Potterton Profile Problem
Roger
The symptoms are that it fires up normally but over the next 10 or so
seconds the gas flame starts to flicker and then goes out. Depending on
whether or not the pilot light goes out as well (it varies) there is a
delay before the sequence is repeated. Is the most likely problem:
a) A failing thermocouple, (which I can presumably source locally)
b) a failing gas valve (replacement where from) or
c) a failing control board (which needs replacing with a reconditioned
one from Geoff)
The boiler is still producing some heat but it is struggling to get the
house up to temperature while it is relatively warm outside. Something
could of course fail permanently at any time and no doubt there is
another cold spell round the corner when the boiler just won't be able
to cope in its present state.
--
Roger Chapman
adder1969
Usually it's something like this.. controls call for heating or
whatever, pcb says ok open gas valve and light the pilot. The
thermocouple then tells it yep the pilot is lit so it starts the fan.
The fan sensor then says yep the fan is working go ahead and open the
main gas valve. If the temp gets too hot then the boiler thermostat
tells it to switch off. if it gets really really hot then the
overheat stat cuts in. So you need to check all the sensors valves
etc in order and work out which is flaky :-)
Roger
<5ff2aa99-a699-4b55...@i29g2000prf.googlegroups.com>
from adder1969 <adde...@yahoo.co.uk> contains these words:
> Usually it's something like this.. controls call for heating or
> whatever, pcb says ok open gas valve and light the pilot. The
> thermocouple then tells it yep the pilot is lit so it starts the fan.
> The fan sensor then says yep the fan is working go ahead and open the
> main gas valve. If the temp gets too hot then the boiler thermostat
> tells it to switch off. if it gets really really hot then the
> overheat stat cuts in. So you need to check all the sensors valves
> etc in order and work out which is flaky :-)
Thanks for that
The way I see it none of the sensors other than the thermocouple are
seeing heat at that stage as the problem is there at start up. So how do
I check for a flaky themocouple short of just fitting a new one?
--
Roger Chapman
Ed Sirett
Roger, seriously, let's start over on this one.
There is no thermocouple on this boiler.
The black control box (available from cetltd) runs everything.
IME the most common fault on the box is that the internal relay does not
acknowledge the APS. This causes the fan to stop and start repeatedly.
This is not the case for you as if you have ANY flames the fan/APS and
controls are good.
The box open the pilot gas valve and begins sparking. If you have ANY
flames then you must have got this far. The same HT lead that lit the
flames now sense that the pilot flame is good, and the box opens the main
gas valve.
The problem looks like its in flame detection and/or reliable flame
detection.
1) Service or get the boiler serviced. Make sure that all the part are
free of crap and the HT lead is in good order and making good contact at
both ends. The mains electric supply is round the right way and the earth
is good.
2) If that fails to harden or remove the fault then replace the HT lead.
3) If you see the main flames even if only for a second then we know the
gas valve is OK. The gas valve is easy to condemn/clear based on it's
supply voltage.
4) If everything appears to be OK then replace the black box.
--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html
geoff
<5ff2aa99-a699-4b55...@i29g2000prf.googlegroups.com>,
adder1969 <adde...@yahoo.co.uk> writes
>On Jan 25, 10:31 am, Roger <ro...@nospam.zetnet.co.uk> wrote:
>> My elderly boiler is having ignition problems.
>>
>> The symptoms are that it fires up normally but over the next 10 or so
>> seconds the gas flame starts to flicker and then goes out. Depending on
>> whether or not the pilot light goes out as well (it varies) there is a
>> delay before the sequence is repeated. Is the most likely problem:
>>
>> a) A failing thermocouple, (which I can presumably source locally)
>>
>> b) a failing gas valve (replacement where from) or
>>
>> c) a failing control board (which needs replacing with a reconditioned
>> one from Geoff)
>>
>> The boiler is still producing some heat but it is struggling to get the
>> house up to temperature while it is relatively warm outside. Something
>> could of course fail permanently at any time and no doubt there is
>> another cold spell round the corner when the boiler just won't be able
>> to cope in its present state.
>>
>> --
>> Roger Chapman
>
>Usually it's something like this.. controls call for heating or
>whatever, pcb says ok open gas valve and light the pilot. The
>thermocouple then tells it yep the pilot is lit so it starts the fan.
>The fan sensor then says yep the fan is working go ahead and open the
>main gas valve.
Sorry, but that's total bollocks
A call for heat powers up the pcb which, if the stat (white wires)
presents a short circuit, brings on the fan, which transfers the air
pressure switch from normally closed to normally open. This feeds back
to the pcb which a) opens the pilot valve and b) powers the spark
circuit. When the pilot flame is established, the pcb senses the flame
by electronic means (there is no thermocouple), and opens the main gas
valve.
--
geoff
geoff
<ro...@nospam.zetnet.co.uk> writes
>My elderly boiler is having ignition problems.
>
>The symptoms are that it fires up normally but over the next 10 or so
>seconds the gas flame starts to flicker and then goes out. Depending on
>whether or not the pilot light goes out as well (it varies) there is a
>delay before the sequence is repeated. Is the most likely problem:
>
>a) A failing thermocouple, (which I can presumably source locally)
there is no thermocouple
>
>b) a failing gas valve (replacement where from) or
could be - or faulty overheat stat, or reduced circulation for some
reason
>
>c) a failing control board (which needs replacing with a reconditioned
>one from Geoff)
No, I don't think it's likely to be the pcb, if the boiler dies with a
reasonably reliable time period
John or Ed are the people to ask here
--
geoff
cynic
> In message <31303030313134344799BA6...@nospam.zetnet.co.uk>, Roger
Just a thought. I once (and only once) came across a gas valve with a
gauze at the inlet. Said gauze was semi-clogged with dust from inside
the gas pipe and when the main falme lit up it starved the pilot which
became unstable and sporadically the flame sense failed. Does the
flame "look" ok during this problem?
Roger
from Ed Sirett <e...@makewrite.demon.co.uk> contains these words:
Thanks for the advice Ed.
> Roger, seriously, let's start over on this one.
> There is no thermocouple on this boiler.
Whoops! I suppose I must have known that once since I installed the
boiler in the first place and have since repaired it.
> The black control box (available from cetltd) runs everything.
> IME the most common fault on the box is that the internal relay does not
> acknowledge the APS. This causes the fan to stop and start repeatedly.
> This is not the case for you as if you have ANY flames the fan/APS and
> controls are good.
> The box open the pilot gas valve and begins sparking. If you have ANY
> flames then you must have got this far. The same HT lead that lit the
> flames now sense that the pilot flame is good, and the box opens the main
> gas valve.
> The problem looks like its in flame detection and/or reliable flame
> detection.
I did think the spark was looking a bit feeble. I have in the past had
to close the gap up (by brute force there being no means of adjustment).
Could a borderline spark gap be responsible?
> 1) Service or get the boiler serviced. Make sure that all the part are
> free of crap and the HT lead is in good order and making good contact at
> both ends. The mains electric supply is round the right way and the earth
> is good.
> 2) If that fails to harden or remove the fault then replace the HT lead.
The fan and the HT lead have both been replaced in recent years.
> 3) If you see the main flames even if only for a second then we know the
> gas valve is OK. The gas valve is easy to condemn/clear based on it's
> supply voltage.
I will try that if reducing the spark gap doesn't make a difference.
> 4) If everything appears to be OK then replace the black box.
I hope it doesn't come to that although Geoffs prices won't break the bank.
Roger
from geoff <ra...@kateda.org> contains these words:
> No, I don't think it's likely to be the pcb, if the boiler dies with a
> reasonably reliable time period
> John or Ed are the people to ask here
Thanks.
--
Roger Chapman
John Stumbles
> The problem looks like its in flame detection and/or reliable flame
> detection.
I had one recently where it sometimes would stick at pilot light on, no
sparking (so flame sense OK) but would not pass Go or collect £200 ... or
fire up the main burner. Turned out to be a dodgy solder joint between the
Molex and the PCB. (Thanks for the telephone consultation Geoff and John
at CET!)
--
John Stumbles
Who's *really* behind all these conspiracy theories?
Roger
from Roger <ro...@nospam.zetnet.co.uk> contains these words:
> > The problem looks like its in flame detection and/or reliable flame
> > detection.
> I did think the spark was looking a bit feeble.
Well I have closed the spark gap down to the minimum (2.5 mm) and the
spark looks ok but it hasn't made a blind bit of difference to my
problem.
I will have to leave the detective work to another day which may not be
as soon as tomorrow unless the problem gets worse as I have an urgent
appointment with my boundary wall. I discovered today that a 15 foot
section of the wall had collapsed into a narrow public path completely
blocking it and as yet I haven't finished removing the rubble. It is a
dry stone wall so will go up again once I have dug down and relaid the
foundation stones but at 6 feet high there is a lot of stone to play
with and only a couple of days of fine (ish) weather in prospect.
--
Roger Chapman
Roger
from cynic <icel...@talktalk.net> contains these words:
> Just a thought. I once (and only once) came across a gas valve with a
> gauze at the inlet. Said gauze was semi-clogged with dust from inside
> the gas pipe and when the main falme lit up it starved the pilot which
> became unstable and sporadically the flame sense failed. Does the
> flame "look" ok during this problem?
It looks ok colourwise (well perhaps a tinge of yellow) but something is
turning the gas supply off in relatively short order.
--
Roger Chapman
geoff
valve problem or it's losing it's power ?
--
geoff
Roger
from geoff <ra...@kateda.org> contains these words:
> Have you put a meter on the solenoid contacts to see if it is a gas
> valve problem or it's losing it's power ?
Not yet, nor even established where I can get probes in. ISTR that last
time I ferreted about in the boiler electrics I had trouble with
shrouded connectors.
The house was up to temperature when I got up so I am not sure whether
the boiler was misbehaving this morning.
They do say that troubles come in threes and to add to the boiler and
boundary wall problems I now have a domestic hot water leak. There is a
puddle partly under the washing machine machine but luckily the source
was a drip from above so I just have to tear up the bathroom floor
rather than tear the washing machine apart.
--
Roger Chapman
Andrew Gabriel
Roger <ro...@nospam.zetnet.co.uk> writes:
> My elderly boiler is having ignition problems.
>
> The symptoms are that it fires up normally but over the next 10 or so
> seconds the gas flame starts to flicker and then goes out. Depending on
> whether or not the pilot light goes out as well (it varies) there is a
> delay before the sequence is repeated. Is the most likely problem:
>
> a) A failing thermocouple, (which I can presumably source locally)
>
> b) a failing gas valve (replacement where from) or
>
> c) a failing control board (which needs replacing with a reconditioned
> one from Geoff)
If the flame dies down gradually, I doubt that's the boiler
as it has no modulation control of the gas valve; sounds like
a lack of gas. Have you got a gas hob, and if so does a lit
gas burner do the same thing at the same time? If so, check
the main gas cock is fully open, and if it is, sounds like
the main regulator has died.
OTOH, if you can hear the gas valve operating simultaneously
as the flames die, then it's not this.
--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]
Roger
> Have you put a meter on the solenoid contacts to see if it is a gas
> valve problem or it's losing it's power ?
I have now checked the gas valve.
Apart from the earth there are 3 wires, black, blue and white. I assume
that black/blue is the 240V supply and white is the control wire.
When calling for heat there is 240V across black/blue whether the boiler
is firing or not.
While the boiler is firing there are no volts on white. When it is not
firing there are 240V on white.
--
Roger Chapman
geoff
>from geoff <ra...@kateda.org> contains these words:
>
>> Have you put a meter on the solenoid contacts to see if it is a gas
>> valve problem or it's losing it's power ?
>
>Not yet, nor even established where I can get probes in.
You should be able to get them into the molex connector on the pcb (pins
1 & 3 from the top I think)
--
geoff
geoff
>from geoff <ra...@kateda.org> contains these words:
>
>> Have you put a meter on the solenoid contacts to see if it is a gas
>> valve problem or it's losing it's power ?
>
>I have now checked the gas valve.
>
>Apart from the earth there are 3 wires, black, blue and white. I assume
>that black/blue is the 240V supply and white is the control wire.
main, pilot and common
There is a basic diagram on the pcb cover which should give you a clue
>
>When calling for heat there is 240V across black/blue whether the boiler
>is firing or not.
>
>While the boiler is firing there are no volts on white. When it is not
>firing there are 240V on white.
>
--
geoff
Roger
from geoff <ra...@kateda.org> contains these words:
> In message <3130303031313...@nospam.zetnet.co.uk>, Roger
> <ro...@nospam.zetnet.co.uk> writes
> >The message <u79ejrs3...@ntlworld.com>
> >from geoff <ra...@kateda.org> contains these words:
> >
> >> Have you put a meter on the solenoid contacts to see if it is a gas
> >> valve problem or it's losing it's power ?
> >
> >I have now checked the gas valve.
> >
> >Apart from the earth there are 3 wires, black, blue and white. I assume
> >that black/blue is the 240V supply and white is the control wire.
> main, pilot and common
> There is a basic diagram on the pcb cover which should give you a clue
T1/T3 Gas Valve
T4/T5 Air pressure switch
T7/T8 Fan
Sorry but none the wiser.
> >
> >When calling for heat there is 240V across black/blue whether the boiler
> >is firing or not.
> >
> >While the boiler is firing there are no volts on white. When it is not
> >firing there are 240V on white.
So is the gas valve working properly or not?
--
Roger Chapman
geoff
<ro...@nospam.zetnet.co.uk> writes
>The message <fugC20ED...@ntlworld.com>
>from geoff <ra...@kateda.org> contains these words:
>
>> In message <3130303031313...@nospam.zetnet.co.uk>, Roger
>> <ro...@nospam.zetnet.co.uk> writes
>> >The message <u79ejrs3...@ntlworld.com>
>> >from geoff <ra...@kateda.org> contains these words:
>> >
>> >> Have you put a meter on the solenoid contacts to see if it is a gas
>> >> valve problem or it's losing it's power ?
>> >
>> >I have now checked the gas valve.
>> >
>> >Apart from the earth there are 3 wires, black, blue and white. I assume
>> >that black/blue is the 240V supply and white is the control wire.
>
>> main, pilot and common
>
>> There is a basic diagram on the pcb cover which should give you a clue
>
>T1/T3 Gas Valve
>T4/T5 Air pressure switch
>T7/T8 Fan
>
>Sorry but none the wiser.
>
>
>> >
>> >When calling for heat there is 240V across black/blue whether the boiler
>> >is firing or not.
>> >
>> >While the boiler is firing there are no volts on white. When it is not
>> >firing there are 240V on white.
>
>So is the gas valve working properly or not?
>
I think it's T1 - T3 = main valve
T2 - T3 = pilot valve
--
geoff
Roger
from geoff <ra...@kateda.org> contains these words:
> >> There is a basic diagram on the pcb cover which should give you a clue
> >
> >T1/T3 Gas Valve
> >T4/T5 Air pressure switch
> >T7/T8 Fan
> >
> >Sorry but none the wiser.
> >
> >
> >> >
> >> >When calling for heat there is 240V across black/blue whether the boiler
> >> >is firing or not.
> >> >
> >> >While the boiler is firing there are no volts on white. When it is not
> >> >firing there are 240V on white.
> >
> >So is the gas valve working properly or not?
> >
> I think it's T1 - T3 = main valve
> T2 - T3 = pilot valve
Sorry, I should have made it clearer. I have the Installation and
Servicing Instructions so I know which connections are which (if I think
to look at the right diagram) but my problem is more basic than that - I
am having trouble work out for sure what I should expect to see on a
meter at each stage of the process. Which process is not being helped by
the fact that I seem to have recorded volts on white the wrong way round
when looking at the boiler last night.
T1 is white and goes to GV2.
T2 is black and goes to GV1.
T3 is blue and is common to GV1 and GV2.
When calling for heat volts present all the time across T2/T3 so is that
the pilot light valve which remains lit during main firing?
When the main burner is firing there are volts on T1/T3 and loss of
volts turns the main burner out so is the gas valve is OK and I need to
look elsewhere for the fault?
But where and what do I look for?
--
Roger Chapman
John Stumbles
> When the main burner is firing there are volts on T1/T3 and loss of
> volts turns the main burner out so is the gas valve is OK and I need to
> look elsewhere for the fault?
Yup, if you're losing voltage acorss the main valve then you need to look
further upstream, on the PCB itself. As I said earlier I had one recently
with a bad solder joint on the PCB to the Molex connector. However the PCB
will drop the main valve if it doesn't sense a flame so watch and listen
(for a quiet 'tick' about 1-2 a second) to see if it's sparking to try to
re-light the pilot.
--
John Stumbles
Xenophobia? Sounds a bit foreign to me.
geoff
<john.s...@ntlworld.com> writes
it could be the overheat turning it off
--
geoff
geoff
While it's sparking, you expect to see volts across T2/T3, that's the
pilot valve
Once the sparking stops, the pcb has sensed that the pilot is alight and
opens the main valve which is across T1/T3
T2/T3 remains energised
>
>When the main burner is firing there are volts on T1/T3 and loss of
>volts turns the main burner out so is the gas valve is OK and I need to
>look elsewhere for the fault?
>
>But where and what do I look for?
>
--
geoff
John Stumbles
> Does the fan go out ?
>
> it could be the overheat turning it off
yebbut he said the pilot only goes out sometimes.
--
John Stumbles
What do you mean, talking about it isn't oral sex?
Roger
from John Stumbles <john.s...@ntlworld.com> contains these words:
> > When the main burner is firing there are volts on T1/T3 and loss of
> > volts turns the main burner out so is the gas valve is OK and I need to
> > look elsewhere for the fault?
> Yup, if you're losing voltage acorss the main valve then you need to look
> further upstream, on the PCB itself. As I said earlier I had one recently
> with a bad solder joint on the PCB to the Molex connector. However the PCB
> will drop the main valve if it doesn't sense a flame so watch and listen
> (for a quiet 'tick' about 1-2 a second) to see if it's sparking to try to
> re-light the pilot.
Can't guarantee that it is always the case but sometimes the pilot flame
has stayed lit and sometimes it has gone out between attempts to light
the main burner and at least some of the times it has gone out the spark
has been visible almost immediately.
I don't actually know what a Molex connector is but if it does come down
to a bad solder joint then I don't think I could remake it sucessfully.
(Now if only it was a matter of hitting it with a big hammer :-().
However the boiler is currently behaving itself so I will have to wait
awhile before I can do any more checking.
--
Roger Chapman
Roger
from geoff <ra...@kateda.org> contains these words:
> >> When the main burner is firing there are volts on T1/T3 and loss of
> >> volts turns the main burner out so is the gas valve is OK and I need to
> >> look elsewhere for the fault?
> >
> >Yup, if you're losing voltage acorss the main valve then you need to look
> >further upstream, on the PCB itself. As I said earlier I had one recently
> >with a bad solder joint on the PCB to the Molex connector. However the PCB
> >will drop the main valve if it doesn't sense a flame so watch and listen
> >(for a quiet 'tick' about 1-2 a second) to see if it's sparking to try to
> >re-light the pilot.
> >
> Does the fan go out ?
> it could be the overheat turning it off
Not as far as I am aware but I have yet to establish a foolproof way of
checking it is running.
--
Roger Chapman
Ed Sirett
> On Sun, 27 Jan 2008 12:49:54 +0000, geoff wrote:
>
>> Does the fan go out ?
>>
>> it could be the overheat turning it off
>
> yebbut he said the pilot only goes out sometimes.
Furthermore the O/H cut out on this boiler is way upstream. IIRC it
breaks all power to the boiler you get absolutely nothing at all until
you have found the brown recessed button underneath and pressed it in.
John Kenyon
"Ed Sirett" <e...@makewrite.demon.co.uk> wrote in message
news:fnih61$b7c$1$8302...@news.demon.co.uk...
> On Sun, 27 Jan 2008 14:37:48 +0000, John Stumbles wrote:
>
> > On Sun, 27 Jan 2008 12:49:54 +0000, geoff wrote:
> >
> >> Does the fan go out ?
> >>
> >> it could be the overheat turning it off
> >
> > yebbut he said the pilot only goes out sometimes.
>
> Furthermore the O/H cut out on this boiler is way upstream. IIRC it
> breaks all power to the boiler you get absolutely nothing at all until
> you have found the brown recessed button underneath and pressed it in.
It also forces the pump on to keep the water flowing through the boiler.
/john
Si
<etl...@gmx.net> writes
temperature?
--
Si
Si
<e...@makewrite.demon.co.uk> writes
>On Sun, 27 Jan 2008 14:37:48 +0000, John Stumbles wrote:
>
>> On Sun, 27 Jan 2008 12:49:54 +0000, geoff wrote:
>>
>>> Does the fan go out ?
>>>
>>> it could be the overheat turning it off
>>
>> yebbut he said the pilot only goes out sometimes.
>
>Furthermore the O/H cut out on this boiler is way upstream. IIRC it
>breaks all power to the boiler you get absolutely nothing at all until
>you have found the brown recessed button underneath and pressed it in.
>
happened about a month ago and, having pressed the recessed button
(can't see what colour it is), the boiler has been running fine since.
Is there anything I should be concerned about if this happens
occasionally?
--
Si
geoff
<john.s...@ntlworld.com> writes
>On Sun, 27 Jan 2008 12:49:54 +0000, geoff wrote:
>
>> Does the fan go out ?
>>
>> it could be the overheat turning it off
>
>yebbut he said the pilot only goes out sometimes.
>
(pcb) fault and I can't offhand think of an obvious reason for a
reliable and regular main valve drop out
--
geoff
John Stumbles
> Is there anything I should be concerned about if this happens
> occasionally?
If it happens often enough to motivate you to track down the problem you
need to check how hot the flow pipe is getting when the cutout cuts out.
An IR thermometer is useful for this (with a bit of plack insulating tape
stuck on the pipe to give a good reading). If the temperature is OK but
the cutout trips replace it. If the temperature really is getting sky high
you probably need to check the boiler thermostat.
--
John Stumbles
Seagull Management
Management technique characterised by flying in, making a lot of noise,
crapping on everything, and then leaving.
Si
<john.s...@ntlworld.com> writes
>On Sun, 27 Jan 2008 18:29:18 +0000, Si wrote:
>
>> Is there anything I should be concerned about if this happens
>> occasionally?
>
>If it happens often enough to motivate you to track down the problem you
>need to check how hot the flow pipe is getting when the cutout cuts out.
>An IR thermometer is useful for this (with a bit of plack insulating tape
>stuck on the pipe to give a good reading).
(I have both of these due to recent threads herein. :)
> If the temperature is OK but
>the cutout trips replace it. If the temperature really is getting sky high
>you probably need to check the boiler thermostat.
>
Thanks John. Tomorrow I'll take a reading of the pipe where it exits the
boiler to get a baseline reading.
--
Si
Roger
from geoff <ra...@kateda.org> contains these words:
> I'm just checking, since, without flame sense problems, it's a rare
> (pcb) fault and I can't offhand think of an obvious reason for a
> reliable and regular main valve drop out
It has become an intermittent problem, and, thinking about it, it may
have been around at a low level for some considerable time. What
triggered my concern was getting up to a house that was 2 degrees short
of being up to temperature, and that after a relatively warm night.
Is there any chance that the ignition lead (which is relatively new) is
good enough to transmit the spark but not good enough to always pass the
flame detection current (assuming that is the way it works)?
I happening to enter the kitchen (to prepare my tea) just before the
room stat decided to call for heat. The on-off start-up procedure went
through about 3 cycles before I abandoned food preparation and moved to
the boiler. Having wasted a few cycles checking the obvious I set about
watching both the volts on the main valve and the burner flame to see if
the flicker in the flame that precedes cut-off was reflected in the
voltage but the boiler had other ideas and I soon got fed up of waiting
for a sign. After several minutes there was another hic-up, but just the
one, so I had missed the chance to do some more checking.
--
Roger Chapman
geoff
>from geoff <ra...@kateda.org> contains these words:
>
>> I'm just checking, since, without flame sense problems, it's a rare
>> (pcb) fault and I can't offhand think of an obvious reason for a
>> reliable and regular main valve drop out
>
>It has become an intermittent problem, and, thinking about it, it may
>have been around at a low level for some considerable time. What
>triggered my concern was getting up to a house that was 2 degrees short
>of being up to temperature, and that after a relatively warm night.
>
>Is there any chance that the ignition lead (which is relatively new) is
>good enough to transmit the spark but not good enough to always pass the
>flame detection current (assuming that is the way it works)?
>
sparking again to try and ignite the pilot (which the pcb doesn't think
is alight because ...)
--
geoff
geoff
you've eliminated the electronics ...
although I'm not convinced that the fault lies there
--
geoff
Roger
from geoff <ra...@kateda.org> contains these words:
> You might be just as well having a pcb from me and then you know that
> you've eliminated the electronics ...
> although I'm not convinced that the fault lies there
You may be right. Expect a telephone call from me sometime this week.
Will I need a new ignition lead? It is relatively new but the original
started shedding insulation when I disturbed it during a routine
service. And if so where from? In the past I have gone to HRPC but they
charge an arm and a leg.
--
Roger Chapman
geoff
>from geoff <ra...@kateda.org> contains these words:
>
>> You might be just as well having a pcb from me and then you know that
>> you've eliminated the electronics ...
>
>> although I'm not convinced that the fault lies there
>
>You may be right. Expect a telephone call from me sometime this week.
>
>Will I need a new ignition lead? It is relatively new but the original
>started shedding insulation when I disturbed it during a routine
>service.
impossible to tell without seeing it
> And if so where from?
Local CH merchant ?
>In the past I have gone to HRPC but they
>charge an arm and a leg.
>
--
geoff
Ed Sirett
it sounds like there may be a reason why the pilot sometimes drops out
(dirt around pilot burner or pilot injector). It might even be that the
pilot flame needs adjusting (screw on gas valve for this, IIRC).
Should the flame die or move away from the spark electrode then the main
GV will be killed in short order. The PCB is fairly basic and as soon as
the the flame failure has occurred the spark generator will try to light
the pilot again.
If the pilot flame/flame sensing was marginal then it's possible the
boiler would effectively be operating on about a 50% duty cycle. Likely
less than 50% of rated output aswell.
Si
<e...@makewrite.demon.co.uk> writes
>On Mon, 28 Jan 2008 09:39:46 +0000, Roger wrote:
>
>> The message <u4wuz4+E...@ntlworld.com> from geoff
>> <ra...@kateda.org> contains these words:
>>
>>> You might be just as well having a pcb from me and then you know that
>>> you've eliminated the electronics ...
>>
>>> although I'm not convinced that the fault lies there
>>
>> You may be right. Expect a telephone call from me sometime this week.
>>
>> Will I need a new ignition lead? It is relatively new but the original
>> started shedding insulation when I disturbed it during a routine
>> service. And if so where from? In the past I have gone to HRPC but they
>> charge an arm and a leg.
>
>it sounds like there may be a reason why the pilot sometimes drops out
>(dirt around pilot burner or pilot injector). It might even be that the
>pilot flame needs adjusting (screw on gas valve for this, IIRC).
>
>Should the flame die or move away from the spark electrode then the main
>GV will be killed in short order.
What's a GV please?
--
Si
Roger
from geoff <ra...@kateda.org> contains these words:
> >> You might be just as well having a pcb from me and then you know that
> >> you've eliminated the electronics ...
> >
> >> although I'm not convinced that the fault lies there
> >
> >You may be right. Expect a telephone call from me sometime this week.
Probably later rather than earlier. I want to have a look at the pilot
light and I am still trying to see whether the gas valve loses volts at
the same time as the burner goes out but the boiler is now on its almost
best behaviour and I have just one odd occasion where the volts appeared
to drop for upwards of half a second without affecting the main burner
but was that just a probe losing contact.
> >
> >Will I need a new ignition lead? It is relatively new but the original
> >started shedding insulation when I disturbed it during a routine
> >service.
> impossible to tell without seeing it
The lead is relatively new. (Well only 5 years old).
> > And if so where from?
> Local CH merchant ?
> >In the past I have gone to HRPC but they
> >charge an arm and a leg.
I am fairly sure I tried Plumb Center before trying HRPC the only time I
needed one.
--
Roger Chapman
Roger
from Ed Sirett <e...@makewrite.demon.co.uk> contains these words:
> it sounds like there may be a reason why the pilot sometimes drops out
> (dirt around pilot burner or pilot injector). It might even be that the
> pilot flame needs adjusting (screw on gas valve for this, IIRC).
The instructions say the pilot is pre set and no adjustment is required.
I will check further when I can find the time but it is not a job I want
to start late in the day and at present I am trying to rebuild a fallen
boundary wall before the rain returns so am outside for much of the day.
> Should the flame die or move away from the spark electrode then the main
> GV will be killed in short order. The PCB is fairly basic and as soon as
> the the flame failure has occurred the spark generator will try to light
> the pilot again.
> If the pilot flame/flame sensing was marginal then it's possible the
> boiler would effectively be operating on about a 50% duty cycle. Likely
> less than 50% of rated output aswell.
Something was marginal. The activity that prompted me to raise the
problem here was a long sequence of short term firing with nowhere near
enough heat output to get the house up to temperature. However since
then there has been only the occasional failure which has made tracking
down what is going wrong all the harder.
--
Roger Chapman
John Stumbles
> What's a GV please?
gas valve
Roger
from Roger <ro...@nospam.zetnet.co.uk> contains these words:
> Probably later rather than earlier. I want to have a look at the pilot
> light and I am still trying to see whether the gas valve loses volts at
> the same time as the burner goes out but the boiler is now on its almost
> best behaviour and I have just one odd occasion where the volts appeared
> to drop for upwards of half a second without affecting the main burner
> but was that just a probe losing contact.
I was driven in by the rain this pm so have had a look at the pilot
flame. From the inspection window the flame does seen to be enveloping
the electrode but after taking the front off the boiler I found that the
guide wasn't pointing quite straight at the electrode so I twisted that
straight rather than attempting to dismantle the assembly and clean the
pilot jet.
On firing up the boiler again it was playing silly buggers for a time so
I put my meter across the main gas valve and watched. No drop in volts
while the main burner was firing so the drop reported above probably was
a probe losing contact. However ISTM that the main burner might be going
out before the volts drop rather than after which I think points to a
gas valve fault rather than an ignition fault but by the time I came to
that conclusion the boiler had reverted to normal operation and I
couldn't do another check.
What I have noticed is that when the pilot light stays lit there are
still one or two sparks before the main boiler fires which (if I
understand correctly) points in the direction a a flame sense fault.
Needless to say I am now more confused than ever.
Going to rain again on Thursday so I will attempt to dismantle the pilot
light assembly then to see if it does need cleaning. Hopefully I can do
this without damaging the ignition lead.
--
Roger Chapman
Roger
from Roger <ro...@nospam.zetnet.co.uk> contains these words:
> Going to rain again on Thursday so I will attempt to dismantle the pilot
> light assembly then to see if it does need cleaning. Hopefully I can do
> this without damaging the ignition lead.
One of my problems is that I only get a brief glimpse of the pilot flame
before the main burner fires up. Is there any way to persuade the pilot
to light without the main burner firing almost immediately? I tried
disconnecting the lead to the main gas valve but that cut the ignition
for some reason. Too clever by half these modern boilers. :-)
--
Roger Chapman
John Stumbles
> One of my problems is that I only get a brief glimpse of the pilot flame
> before the main burner fires up. Is there any way to persuade the pilot
> to light without the main burner firing almost immediately? I tried
> disconnecting the lead to the main gas valve but that cut the ignition
> for some reason. Too clever by half these modern boilers. :-)
That's because the moulded 3-way connector does the pilot as well as the
main valve. You can pull the main valve connector out of the Molex
(pushing the locking barb down to do so) to get just pilot running.
--
John Stumbles
Who's *really* behind all these conspiracy theories?
Roger
from John Stumbles <john.s...@ntlworld.com> contains these words:
> > One of my problems is that I only get a brief glimpse of the pilot flame
> > before the main burner fires up. Is there any way to persuade the pilot
> > to light without the main burner firing almost immediately? I tried
> > disconnecting the lead to the main gas valve but that cut the ignition
> > for some reason. Too clever by half these modern boilers. :-)
> That's because the moulded 3-way connector does the pilot as well as the
> main valve. You can pull the main valve connector out of the Molex
> (pushing the locking barb down to do so) to get just pilot running.
Thanks John but I can't see why that would be be different from pulling
the connector off the terminal at the other end of the white wire.
I had the pilot assembly to bits and gave it a clean it didn't really
need and the end result is the same as before - no change. Boiler
misbehaves for longer than I am prepared to watch it for before
reverting to normal, or almost normal working.
So I am now in the position that so many repair men find themselves in
constantly. :-) About to replace components one by one until the problem
is solved. On the assumption that the control module is going to be
cheaper than a gas valve and more easily sourced Geoff can expect a
telephone call some time tomorrow (Thursday).
Any pointers for a gas valve supplier. (Honeywell VR4700E1034. Potterton
G.C. part numbers 907704 and 395796).
--
Roger Chapman
Nearest Marilyn
geoff
>from John Stumbles <john.s...@ntlworld.com> contains these words:
>
>> > One of my problems is that I only get a brief glimpse of the pilot flame
>> > before the main burner fires up. Is there any way to persuade the pilot
>> > to light without the main burner firing almost immediately? I tried
>> > disconnecting the lead to the main gas valve but that cut the ignition
>> > for some reason. Too clever by half these modern boilers. :-)
>
>> That's because the moulded 3-way connector does the pilot as well as the
>> main valve. You can pull the main valve connector out of the Molex
>> (pushing the locking barb down to do so) to get just pilot running.
>
>Thanks John but I can't see why that would be be different from pulling
>the connector off the terminal at the other end of the white wire.
>
I know of no reason why disabling the main valve by removing one of the
connectors should prevent the pcb from sparking
If you remove the common from the two gas valves, of course, you would
stop the pilot valve from opening
--
geoff
Roger
from geoff <ra...@kateda.org> contains these words:
> I know of no reason why disabling the main valve by removing one of the
> connectors should prevent the pcb from sparking
> If you remove the common from the two gas valves, of course, you would
> stop the pilot valve from opening
No, the blue (common) was not disturbed.
The boiler was firing this am when I got up although the house was not
up to temperature so I turned the supply off and removed the white wire
from the main gas valve before restoring the supply. The start-up
sequence didn't so I left it on just in case the turn-off had triggered
the over-run phase.
After some minutes the start-up did commence but not to the extent of
ignition of the pilot light so I touched the detached wire to its
terminal and the boiler fired up. Removing the wire again left the pilot
flame alight (at long last!) and FWIW the flame looked perfectly healthy
to me.
--
Roger Chapman
Roger
thanks) which further muddies the waters. Fault could be with the
pressure switch.
John's detailed advice was to check the resistance of both the NC and NO
connections on the micro-switch and to check for air leakage. The
resistance on the NC circuit was OK but I was unable to persuade the
pressure switch to switch by blowing in either tube (I didn't want to
blow too hard having been warned about possible damage) so couldn't
complete the tests.
As I see it the pressure switch is the most likely candidate (not
withstanding my failure to check it out properly) as the boiler problem
certainly seems worse when there is a gale blowing outside so I intend
to replace that first.
Pressure swithes don't appear to be on Cetltds supply list.
A quick google throws up keeptheheaton.com as a supplier. Before I
commit to them has anybody got any experience dealing with them?
--
Roger Chapman
geoff
>thanks) which further muddies the waters. Fault could be with the
>pressure switch.
>
>John's detailed advice was to check the resistance of both the NC and NO
>connections on the micro-switch and to check for air leakage. The
>resistance on the NC circuit was OK but I was unable to persuade the
>pressure switch to switch by blowing in either tube (I didn't want to
>blow too hard having been warned about possible damage) so couldn't
>complete the tests.
>
>As I see it the pressure switch is the most likely candidate (not
>withstanding my failure to check it out properly) as the boiler problem
>certainly seems worse when there is a gale blowing outside so I intend
>to replace that first.
>
>Pressure swithes don't appear to be on Cetltds supply list.
>
--
geoff
John Stumbles
> John's detailed advice was to check the resistance of both the NC and NO
> connections on the micro-switch and to check for air leakage. The
> resistance on the NC circuit was OK but I was unable to persuade the
> pressure switch to switch by blowing in either tube (I didn't want to
> blow too hard having been warned about possible damage) so couldn't
> complete the tests.
It should click over with a very gentle blow - sort of as much as you'd
give to make a candle flame flicker but nowhere near as much as to
make it go out.
--
John Stumbles
Bob the builder / it'll cost 'yer
Bob the builder / loadsa dosh
Roger
from John Stumbles <john.s...@ntlworld.com> contains these words:
> > John's detailed advice was to check the resistance of both the NC and NO
> > connections on the micro-switch and to check for air leakage. The
> > resistance on the NC circuit was OK but I was unable to persuade the
> > pressure switch to switch by blowing in either tube (I didn't want to
> > blow too hard having been warned about possible damage) so couldn't
> > complete the tests.
> It should click over with a very gentle blow - sort of as much as you'd
> give to make a candle flame flicker but nowhere near as much as to
> make it go out.
Does it matter which tube?
Because the ends of the tubes close to the pressure switch was so
ackward to get to I was using the remote ends. Perhaps they are just too
remote for the switch to notice a shortish blow.
--
Roger Chapman
geoff
as long as it goes into the APS
it only depends whether you suck or blow, obviously
--
geoff
Roger
from Roger <ro...@nospam.zetnet.co.uk> contains these words:
> As I see it the pressure switch is the most likely candidate (not
> withstanding my failure to check it out properly) as the boiler problem
> certainly seems worse when there is a gale blowing outside so I intend
> to replace that first.
Pressure switch now on order and should be delivered Monday.
If that doesn't do the trick it will have to be the pcb and after that
the gas valve. I wonder at what point I should start thinking about a
new boiler.
--
Roger Chapman
adder1969
>
> Pressure switch now on order and should be delivered Monday.
>
> If that doesn't do the trick it will have to be the pcb and after that
> the gas valve. I wonder at what point I should start thinking about a
> new boiler.
>
> --
> Roger Chapman
I've missed a lot of this thread but can you not hard wire the
pressure switch just to see if that makes it reliable?
Roger
<468880fc-d320-4f6d...@j78g2000hsd.googlegroups.com>
from adder1969 <adde...@yahoo.co.uk> contains these words:
> > Pressure switch now on order and should be delivered Monday.
> >
> > If that doesn't do the trick it will have to be the pcb and after that
> > the gas valve. I wonder at what point I should start thinking about a
> > new boiler.
> I've missed a lot of this thread but can you not hard wire the
> pressure switch just to see if that makes it reliable?
I may have got the wrong end of the stick but I am under the impression
that the switch needs the normally closed contacts in the initial
sequence and that just shorting out the normally open contacts was not
an option. I don't have either the equipment or the ability to wire an
over ride switch in parallel to the NO contacts and in any case the die
is cast so unless the boiler completely ceases to work I don't intend to
try anything else untill the new switch is delivered.
--
Roger Chapman
Ed Sirett
The online suppliers are all OK.
Part Centre (HRPC IIRC) are part of the Wolseley group and have taken up
an anti-diy policy, how they police this on line? I expect they don't.
Ed Sirett
There are flow restrictors in the tubes which slow everything down, but
in principal you should be able to use the end of the tubes.
geoff
<468880fc-d320-4f6d...@j78g2000hsd.googlegroups.com>,
adder1969 <adde...@yahoo.co.uk> writes
No
The pcb tests that the APS is in the NC position initially to prevent a
false signal in the event that the APS contacts had stuck (welded
themselves) in the normally open position
--
geoff
John Stumbles
> Part Centre (HRPC IIRC) are part of the Wolseley group and have taken up
> an anti-diy policy, how they police this on line? I expect they don't.
The same way they police it at our local TC then :-)
--
John Stumbles
87.5% of statistics are made up
Mike Tomlinson
<john.s...@ntlworld.com> writes
>Turned out to be a dodgy solder joint between the
>Molex and the PCB.
Those Molex connectors are notorious for developing dry joints. I came
across literally hundreds when I was working in monitor repair.
--
(\__/) Bunny says NO to Windows Vista!
(='.'=) http://www.cs.auckland.ac.nz/~pgut001/pubs/vista_cost.html
(")_(")
geoff
<mi...@jasper.org.uk> writes
>In article <Z5tmj.5259$L73....@newsfe1-win.ntli.net>, John Stumbles
><john.s...@ntlworld.com> writes
>
>>Turned out to be a dodgy solder joint between the
>>Molex and the PCB.
>
>Those Molex connectors are notorious for developing dry joints.
I spend my life telling people about cracked joints
They're not dry joints, are they ?
--
geoff
Tim Lamb
writes
Hmm..
I think electronics industry speak (of about 40 years ago) was that
solder *wet* the copper track in forming a sound joint. Hence any failed
solder joint was referred to as *dry*.
The Potterton profile that you and others kindly helped me fix 2 years
back had two *dry* joints where the mains connector is soldered to the
circuit board. As was pointed out at the time, a magnifying glass is
essential to spot this fault.
regards
>
>
--
Tim Lamb
geoff
<t...@marfordfarm.demon.co.uk> writes
>In message <DysFx7RP...@ntlworld.com>, geoff <ra...@kateda.org>
>writes
>>In message <tZeoysA0...@jasper.org.uk>, Mike Tomlinson
>><mi...@jasper.org.uk> writes
>>>In article <Z5tmj.5259$L73....@newsfe1-win.ntli.net>, John Stumbles
>>><john.s...@ntlworld.com> writes
>>>
>>>>Turned out to be a dodgy solder joint between the
>>>>Molex and the PCB.
>>>
>>>Those Molex connectors are notorious for developing dry joints.
>>
>>I spend my life telling people about cracked joints
>>
>>They're not dry joints, are they ?
>
>Hmm..
>
>I think electronics industry speak (of about 40 years ago) was that
>solder *wet* the copper track in forming a sound joint. Hence any
>failed solder joint was referred to as *dry*.
No hence about it
Yes, a dry joint is one where the solder has not wet the metal
That's completely different to one where the solder has actually cracked
>
>The Potterton profile that you and others kindly helped me fix 2 years
>back had two *dry* joints where the mains connector is soldered to the
>circuit board. As was pointed out at the time, a magnifying glass is
>essential to spot this fault.
>
>regards
>>
>>
>
--
geoff
Roger
First I changed the pressure switch - problem remains.
So I changed the pcb. In doing so I noticed the connection from ignition
lead to pcb connection was slack so fitted new ignition lead as well but
the problem still remains.
So now on the horns of a delemma. Change the gas valve on the basis that
it is now the obvious candidate or investigate further first to see if I
can eliminate for sure the whole fan/pressure switch area.
Or just wait till the boiler finally expires and fit a replacement boiler.
Must say I am impressed with the speed with which the repacement pcb
arrived. It was after 3pm yesterday when I phoned Geoff but City Link
delivered it at 9.05am today. Doesn't look as if I will be using them
for the return though. Can't get their services page to load.
--
Roger Chapman
adder1969
> Update.
>
> First I changed the pressure switch - problem remains.
>
> So I changed the pcb. In doing so I noticed the connection from ignition
> lead to pcb connection was slack so fitted new ignition lead as well but
> the problem still remains.
>
> So now on the horns of a delemma. Change the gas valve on the basis that
> it is now the obvious candidate or investigate further first to see if I
> can eliminate for sure the whole fan/pressure switch area.
>
> Or just wait till the boiler finally expires and fit a replacement boiler.
>
>
I guess it depends on how valuable your time is. At the risk of
showing my ignorance can you not either test the output from the PCB
to the valve to see if it's stable and/or test the valve in place with
a reliable power supply?
Roger
from adder1969 <adde...@yahoo.co.uk> contains these words:
> I guess it depends on how valuable your time is. At the risk of
> showing my ignorance can you not either test the output from the PCB
> to the valve to see if it's stable and/or test the valve in place with
> a reliable power supply?
Being retired my time doesn't have much value although I have had to
break off from digging out a blocked field drain to fit the pcb and d/w
the follow-up. However when it comes to messing with 240 volts I am
rather cautious. Holding the probes of a meter will watching both flame
and meter is about my limit. I am considering wiring neons across the
relevant connections but not having any piggy-back connectors any such
wiring would be rather insecure and so would I be.
The supply to the gas valve broadly matches whether the valve is on or
off but I cannot be sure whether the valve failing triggers the switch
off or whether the switch off is in response to another factor. Geoff
thinks it might be the fan but all it would take is a leak in the
pipework twixt fan and pressure switch.
One of the puzzling (to me) factors is that the problem usually clears
after a period. My past experience with a failing fan was that much the
reverse was the case with the boiler dying after a period in operation
rather than problems mainly at start-up.
--
Roger Chapman
Ed Sirett
I'm still not convinced that pilot flame stays in the electrode.
There is an alternative connector for the gas valve which allows the
pilot only (IIRC) to operate and also for the pcb to be swung down. This
allows more involved live testing.
Roger
from Ed Sirett <e...@makewrite.demon.co.uk> contains these words:
> I'm still not convinced that pilot flame stays in the electrode.
> There is an alternative connector for the gas valve which allows the
> pilot only (IIRC) to operate and also for the pcb to be swung down. This
> allows more involved live testing.
The destructions mention this only in the commissioning section and
specifically say "Gas will flow to the pilot only. It will not be
ignited as the ignition system is de-energised."
As I mentioned in a previous post I managed to get the pilot to light by
touching the detached main gas valve lead to the terminal until it fired
and then removing it again. Pilot remained lit. I only let this carry on
for as long as it took to establish that the pilot flame did what it
said it should do in the book. Perhaps I should have left it on for an
extended period to see if it went out although I am still not sure what
that would have told me. Under fault conditions sometime the pilot goes
out and sometimes it doesn't and sometimes I could see it sparking even
though it stayed alight and sometimes I didn't see sparking. (There is
an outside possibility that I have been misled but a very rapid
relight).
--
Roger Chapman
Ed Sirett
If it's sparking then the PCB 'thinks' the pilot has gone out even though
it hasn't actually gone out.
1) Earth OK and polarity OK.
2) electrode in the pilot flame
3) ignition lead.
4) pcb.
3 and 4 have been checked /replaced.
IIRC you checked 1 yonks ago.
That leaves 2. Maybe the pilot flame is too small? So maybe the pilot
injector needs cleaning.
Roger
from Ed Sirett <e...@makewrite.demon.co.uk> contains these words:
> That leaves 2. Maybe the pilot flame is too small? So maybe the pilot
> injector needs cleaning.
The pilot flame looked alright when I finally got to see it for more
than an instant but by then I had already dismantled and cleaned the
pilot assembly although it didn't look to me as as though it needed
cleaning.
--
Roger Chapman
Nearest Marilyn still to be visited - Great Orme.
89 miles as the crow flies,
considerably more as the walker drives.
John Stumbles
> The supply to the gas valve broadly matches whether the valve is on or
> off but I cannot be sure whether the valve failing triggers the switch
> off or whether the switch off is in response to another factor. Geoff
> thinks it might be the fan but all it would take is a leak in the
> pipework twixt fan and pressure switch.
>
> One of the puzzling (to me) factors is that the problem usually clears
> after a period. My past experience with a failing fan was that much the
> reverse was the case with the boiler dying after a period in operation
> rather than problems mainly at start-up.
Er, have you checked the flexi pipes to the APS? They can split and leak
intermittently, which might cause the symptoms you're seeing.
--
John Stumbles
Roger
from John Stumbles <john.s...@ntlworld.com> contains these words:
> > One of the puzzling (to me) factors is that the problem usually clears
> > after a period. My past experience with a failing fan was that much the
> > reverse was the case with the boiler dying after a period in operation
> > rather than problems mainly at start-up.
> Er, have you checked the flexi pipes to the APS? They can split and leak
> intermittently, which might cause the symptoms you're seeing.
They look OK but were too short for me to (as advised by John) trim the
ends back. I had hoped the pressure switch might have come complete with
pipes as I don't have a part number for the pipes. Given the hot
environment I presume any old pipe won't do as a substitute.
The metal intermediate pipe is largely concealed so I can't check that
accept by doing a leak test. When I get round to buying a manometer I
can use that to check the integrity of the pipes.
--
Roger Chapman
Ed Sirett
> The message <foapjt$qmi$2$8300...@news.demon.co.uk> from Ed Sirett
> <e...@makewrite.demon.co.uk> contains these words:
>
>> That leaves 2. Maybe the pilot flame is too small? So maybe the pilot
>> injector needs cleaning.
>
> The pilot flame looked alright when I finally got to see it for more
> than an instant but by then I had already dismantled and cleaned the
> pilot assembly although it didn't look to me as as though it needed
> cleaning.
Is the electrode nicely in the flame and not shorting out anywhere?
Roger
from Ed Sirett <e...@makewrite.demon.co.uk> contains these words:
> > The pilot flame looked alright when I finally got to see it for more
> > than an instant but by then I had already dismantled and cleaned the
> > pilot assembly although it didn't look to me as as though it needed
> > cleaning.
> Is the electrode nicely in the flame and not shorting out anywhere?
Was when I got a good look and the ignition lead is new so the should be
no problem there.
I have just had a computer glitch that kept me off the internet. It may
well return so if I don't respond to a future message it may be that I
have been prevented from reading it. IOf something got at my computer
once it could easily do it again.
(Had to restore to yesterday (first restore I have ever had to do) and
McAfee is doing its nut. Signature file more than 30 days old and some
parts missing - reinstall required and I haven't a clue where the
original disk is. Oh well, initial info was apparently wrong as it now
says protection restored and UTD.)
--
Roger Chapman
John Stumbles
> They look OK but were too short for me to (as advised by John) trim the
> ends back. I had hoped the pressure switch might have come complete with
> pipes as I don't have a part number for the pipes. Given the hot
> environment I presume any old pipe won't do as a substitute.
You can buy silicone pipe for this at HRPC (Parts Center), and probably
other places. Quite handy for rescuing ignition leads whose insulation is
breaking down to chassis if you haven't got a suitable replacement lead.
--
John Stumbles
Testiculate [v.t]
To wave one's arms around while talking bollocks.
Roger
from John Stumbles <john.s...@ntlworld.com> contains these words:
> > They look OK but were too short for me to (as advised by John) trim the
> > ends back. I had hoped the pressure switch might have come complete with
> > pipes as I don't have a part number for the pipes. Given the hot
> > environment I presume any old pipe won't do as a substitute.
> You can buy silicone pipe for this at HRPC (Parts Center), and probably
> other places. Quite handy for rescuing ignition leads whose insulation is
> breaking down to chassis if you haven't got a suitable replacement lead.
Thanks John
The reason I haven't posted any more on this subject is because I
haven't been doing any further investigation since fitting the ignition
module. Partly that is because I have been taking advantage of the
unseasonal weather but mostly because the only time I have seen (or
heard) the boiler malfunction since I fitted the new module was on
start-up after said fitting. It might just be coincidence but the wind
has dropped since then.
--
Roger Chapman
Roger
earlier thread the problem is intermittent running with periods
typically of about 10 seconds firing followed by a brief shut-down,
particularly on start-up but also at other times. Pressure switch,
ignition lead and ignition module have been changed and the pilot jet,
pilot flame and spark gap checked.
Since changing the ignition module there was only one brief period
during which the boiler misbehaved. Since then the weather has been calm
and the problem not noticeable. This afternoon the wind got up and the
problem returned. I must get my finger out and get some replacement
tubing as suggested earlier in the thread as the problem surely must be
in the pressure sensing area.
--
Roger Chapman
geoff
bit of a breeze and the bugger drops out
?
email me some photos esp. of the flue outside, I'll see if John can
shine some light on the problem
--
geoff
Roger
from geoff <ra...@kateda.org> contains these words:
> So - no wind, no problem
> bit of a breeze and the bugger drops out
> ?
Bit more than a bit of a breeze. My wind gauge only updates every few
minutes but the last few times I have looked it has been circa 20 mph
and it certainly sounds worse than that. (I think I need a new weather
station, wind and rain are the only sensors left working and I don't
trust either of them).
> email me some photos esp. of the flue outside, I'll see if John can
> shine some light on the problem
Thanks. Will do when it is light. It is not an ideal placement being
close to the corner on the windy (West) of the house.
If you want an aerial view and have the updated version of Google Earth
stick Marley, England in the box and it will take you here. :-)
--
Roger Chapman
geoff
It seems that the problem is that, for some reason, wind conditions are
creating a reduction in pressure which is causing the APS to drop out
--
geoff
Roger
from geoff <ra...@kateda.org> contains these words:
> >> email me some photos esp. of the flue outside, I'll see if John can
> >> shine some light on the problem
> >
> >Thanks. Will do when it is light. It is not an ideal placement being
> >close to the corner on the windy (West) of the house.
> >
> >If you want an aerial view and have the updated version of Google Earth
> >stick Marley, England in the box and it will take you here. :-)
> >
> More interested in the placement of the flue than proximity of trees
> It seems that the problem is that, for some reason, wind conditions are
> creating a reduction in pressure which is causing the APS to drop out
Photo dispatched.
Trees not an issue. The large sycamore that used to standing in my
neighbours field overshadowing the west end of the house was condemned
and cut down a few years back.
The remark about Google Earth was really prompted by the coincidence of
just finding that the new version had plonked a big red dot in my
locality that, when viewed from altitude, obscured my house. You won't
find this Marley in any road atlas, indeed it isn't properly identified
even on the OS 1:25,000.
--
Roger Chapman
Roger
from geoff <ra...@kateda.org> contains these words:
> It seems that the problem is that, for some reason, wind conditions are
> creating a reduction in pressure which is causing the APS to drop out
Just an afterthought.
About 4 inches from the end of the flue there is a chevron shaped hole
between the inlet and the exhaust about one square inch in area,
presumably where the condensate had managed to pool. Is this likely to
have any effect?
--
Roger Chapman
Tim Lamb
>just finding that the new version had plonked a big red dot in my
>locality that, when viewed from altitude, obscured my house. You won't
>find this Marley in any road atlas, indeed it isn't properly identified
>even on the OS 1:25,000.
Huh! The map overlay puts an access roadway cutting diagonally across
one of my fields.
If they got this stuff from O.S. you have to wonder what was being
mooted at the time.
regards
>
--
Tim Lamb
geoff
--
geoff
Roger
from Tim Lamb <t...@marfordfarm.demon.co.uk> contains these words:
> >The remark about Google Earth was really prompted by the coincidence of
> >just finding that the new version had plonked a big red dot in my
> >locality that, when viewed from altitude, obscured my house. You won't
> >find this Marley in any road atlas, indeed it isn't properly identified
> >even on the OS 1:25,000.
Just to make another point about Marley there are several square miles
of it and I am right on the boundary so Google Earth haven't got it
entirely right.
> Huh! The map overlay puts an access roadway cutting diagonally across
> one of my fields.
A nonexistent road rather than just a misplaced road?
> If they got this stuff from O.S. you have to wonder what was being
> mooted at the time.
In my experience the OS is almost always expensive and out of date. They
do however incorporate deliberate errors to catch copyright thieves so
it is possible. It should have been cheaper for Google to source their
road maps from one of the road map specialists but they don't always get
it right. My in-car sat-nav has several times tried to take me down
tracks I would not consider unless driving a tractor.
--
Roger Chapman
Tim Lamb
>> one of my fields.
>
>A nonexistent road rather than just a misplaced road?
Yes.
It is likely that alternative routes to reach a prospective tip site
would have been under discussion around 1990. The Google photo is
perhaps later as it shows the route that was agreed and begun.
We purchased the land as sitting tenants so were not party to any
discussions with highway road planners.
>
>> If they got this stuff from O.S. you have to wonder what was being
>> mooted at the time.
>
>In my experience the OS is almost always expensive and out of date. They
>do however incorporate deliberate errors to catch copyright thieves so
>it is possible. It should have been cheaper for Google to source their
>road maps from one of the road map specialists but they don't always get
>it right. My in-car sat-nav has several times tried to take me down
>tracks I would not consider unless driving a tractor.
Yes again.
Byways, strictly BOATS are included in sat nav info. Legally there is a
right to pass with a vehicle.
regards
>
--
Tim Lamb
Roger
The basic problem is that at certain times the boiler refuses to fire
continuously for any length of time. Typically it is at start-up. After
the pilot flame lights the main burner will fire for a period of maybe
10 seconds during which time the main burner flame starts to flutter and
eventually quite abruptly goes out. This cycle can repeat time after
time but after I have given up watching it the boiler will start
functioning normally. Well almost every time. This thread was triggered
by the boiler continuing to misbehave one very cold and windy morning
and the house not getting anywhere near up to temperature before I got
up. There does seem to be a close connection between boiler malfunction
and wind strength but that could be a coincidence.
The pressure switch, ignition lead and ignition module have all been
replaced without significant changes.
During the extended course of the investigation I noticed that although
I could hear the ignition sparking I couldn't at times see it so the
whole pilot and electrode assembly has now been changed. There is now a
possible explanation for the hidden spark. With the new assembly I can
actually see that at times the spark prefers the larger gap between the
pilot flame shroud to the side of the electrode to the proper spark gap
at the end of the electrode.
The other difference is that with the boiler casing on and viewing
through the little porthole I can now actually see at least part of the
pilot flame when the main burner is firing. Previously the pilot flame
was masked by the main burner in the background.
Last night I found a major difference between the way in which the
boiler operated with or without the casing on. With the casing off the
pilot fame started with something of a roar and with the flame foot
nowhere near the jet. Up to more than a second could elapse before the
pilot flame became normal and during this time the ignition continued to
spark. Once the main burner fired the boiler functioned normally. With
the casing back on the pilot flame lit normally but the main burner went
into misbehave mode. Again might just be coincidence but if so a
consistent coincidence IYSWIM.
I have at long last bought an el cheapo U tube manometer. According to
that the burner pressure is a fraction over 15 mb (perhaps 15.2 or 15.3)
while according to the book it should be 14.9. The meter reading was
about 24 mb without usage and about 20.5 when the boiler was on but with
the boiler kicking in and out it was difficult to get a steady reading.
The reason I have been quiet on this for so long is that I have been
picking Geoff's brains by e-mail (for which many thanks Geoff) but I
think it is about time I gave him a rest.
Being at long last able to see the pilot flame while the boiler is
misbehaving I can see that that flame is not consistent. The flame foot
keeps moving away from the jet and at times even seems to extend past
the the end of the pilot shroud. This may well be the trigger for boiler
malfunction.
About the only think of note I haven't replaced is the gas valve and
that as much because of a reluctance to mess with gas soundness as for
any other reason but before I do take that step please has anyone any
further views on this seemingly intractable problem.
--
Roger Chapman
Ed Sirett
There a pilot flame adjustment screw on the gas valve see the book to
find the exact location. Although the book says that the pilot needs no
adjustment it looks like it might just need it in this case. Especially
try to make sure the setting lights reliably, reliably lights the main
burner and never lifts off.
geoff
<e...@makewrite.demon.co.uk> writes
Ha
ROger - it might be worth forwarding some of our email correspondence to
Ed
Ed - there are several problems - spark tracking along the ceramic,
flame lift off, possible recirculation of POC
--
geoff
Roger
from Ed Sirett <e...@makewrite.demon.co.uk> contains these words:
> > About the only think of note I haven't replaced is the gas valve and
> > that as much because of a reluctance to mess with gas soundness as for
> > any other reason but before I do take that step please has anyone any
> > further views on this seemingly intractable problem.
> There a pilot flame adjustment screw on the gas valve see the book to
> find the exact location. Although the book says that the pilot needs no
> adjustment it looks like it might just need it in this case. Especially
> try to make sure the setting lights reliably, reliably lights the main
> burner and never lifts off.
My boiler is fitted with the Honeywell valve. The destructions I have
only document the main burner pressure adjustment which is a tiny screw
set in the face of the valve casing midway along the bottom edge.
There is also a similar sized screw in a little turret at the bottom
left hand corner of the valve which is the pilot flame side. Doesn't
seem to want to turn though, at least not easily.
--
Roger Chapman
Roger
from geoff <ra...@kateda.org> contains these words:
> Ha
> ROger - it might be worth forwarding some of our email correspondence to
> Ed
OK with you Ed?
> Ed - there are several problems - spark tracking along the ceramic,
> flame lift off, possible recirculation of POC
The tracking may have been on the ceramic before I changed the pilot
assembly but currently the misplaced spark is from the metal shroud of
the pilot flame to the metal stem of the electrode rather than across
the smaller gap from the tip of the electrode to the earthing strip.
Given that these two elements are part of the same metal assembly I
can't understand why that should be. I will have the assembly out again
later today and see if using the new jet and electrode in the old frame
makes any difference.
What I can't get out of the back of my mind is that with the main burner
flame playing up before the main gas valve switches off there has to be
something wrong with the gas valve itself rather than the control system
outwith the valve.
I didn't notice any fumes being expelled into the room when the boiler
case was off but if I can find the spare gaskets I will take the fan out
and check that the exhaust is clear downstream of the fan.
--
Roger Chapman
John Stumbles
> There is also a similar sized screw in a little turret at the bottom
> left hand corner of the valve which is the pilot flame side. Doesn't
> seem to want to turn though, at least not easily.
I think you'll find that's a pressure test point: you loosen the screw and
stick your manometer tube onto the turret bit.
--
John Stumbles
Pessimists are never disappointed
John Stumbles
> The pressure switch, ignition lead and ignition module have all been
> replaced without significant changes.
And the pressure switch rubber hoses?
Not very likely to be the problem but cheap & easy enough to do.
--
John Stumbles
Xenophobia? Sounds a bit foreign to me.
Roger
from John Stumbles <john.s...@ntlworld.com> contains these words:
> > There is also a similar sized screw in a little turret at the bottom
> > left hand corner of the valve which is the pilot flame side. Doesn't
> > seem to want to turn though, at least not easily.
> I think you'll find that's a pressure test point: you loosen the screw and
> stick your manometer tube onto the turret bit.
That makes sense. Presumably needed to adjust the pilot flame.
There is another possible adjustment screw near the top edge but that is
more than twice the size of the main burner one.
Much of this morning I spent cleaning the heat exchanger. More muck in
there than I expected.
Boiler currently back on to warm the house up again. Wind is relatively
light and the boiler is only occasionally misbehaving.
The view through the observation porthole is not very good but I remain
convinced I can see the foot of the pilot flame oscillating between the
jet and the end of the pilot flame shroud.
Not had time as yet to mess with the pilot flame assembly again.
--
Roger Chapman
Roger
from John Stumbles <john.s...@ntlworld.com> contains these words:
> > The pressure switch, ignition lead and ignition module have all been
> > replaced without significant changes.
> And the pressure switch rubber hoses?
> Not very likely to be the problem but cheap & easy enough to do.
There are not a problem. I eventually fitted a neon from the NO on the
pressure switch to neutral and the switch definitely stays on while the
boiler malfunctions. I ran it that way for several days and there was
never any suggestion the pressure switch wasn't working as it should.
--
Roger Chapman
Ed Sirett
> On Thu, 28 Feb 2008 11:36:56 +0000, Roger wrote:
>
>> The pressure switch, ignition lead and ignition module have all been
>> replaced without significant changes.
>
> And the pressure switch rubber hoses?
>
> Not very likely to be the problem but cheap & easy enough to do.
I don't think there can be any APS problems as you would not even get any
a pilot flame.
Ed Sirett
OK I've been out of the loop on this one. The (flame) lift off I'm
referring to is when the pilot flame loses contact with the pilot
assembly. It might also accompanied by a small roaring sound (which you
probably can't hear inside the casing over the sound of the fan).
What is the gas pressure from the meter at the boiler inlet? Does any
similar flame lift happen on the gas rings (if you have them)?.