Central heating auto bypass valve - setting?

[Tim Watts]

I've balancing my new CH - noticed the flow and return to the boiler
were virtually the same - and the auto bypass valve was set to minimum
(0.1 bar = 1m head water IIRC)

Closing it down to 0.4 bar has jumped the differential temperature - but
I suspect that's too high.

The Worcester manual says the pump can deliver 2m head for "21C
temperature rise" - nothing else about min flow rates or bypass pressure.

Any ideas? If I turn it to 0.2bar the flow temperature starts to creep up.

Now this may also suggest I have the lockshields all turned down too low
as well (I've opened 1/4 - 3/4 turn as a starting point).

[John Rumm]

I have mine set pretty high - based on the assumption that I only want
it to do anything when nearly all the TRVs are closed off. A highish
differential temperature should keep condensing efficiency up as well.

--
Cheers,

John.

/=================================================================\
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\=================================================================/

[Tim Watts]

On 11/11/17 16:59, John Rumm wrote:
> On 11/11/2017 11:44, Tim Watts wrote:
>> I've balancing my new CH - noticed the flow and return to the boiler
>> were virtually the same - and the auto bypass valve was set to minimum
>> (0.1 bar = 1m head water IIRC)
>>
>> Closing it down to 0.4 bar has jumped the differential temperature - but
>> I suspect that's too high.
>>
>> The Worcester manual says the pump can deliver 2m head for "21C
>> temperature rise" - nothing else about min flow rates or bypass pressure.
>>
>> Any ideas? If I turn it to 0.2bar the flow temperature starts to creep
>> up.
>>
>> Now this may also suggest I have the lockshields all turned down too low
>> as well (I've opened 1/4 - 3/4 turn as a starting point).
>
>
> I have mine set pretty high - based on the assumption that I only want
> it to do anything when nearly all the TRVs are closed off. A highish
> differential temperature should keep condensing efficiency up as well.
>

Thanks John.

After balancing round 1 (a differential thermometer with 2 pipe clamps
certainly makes this quicker!), I have 10-12 across all rads more or
less at a flow to rad of 56C (boiler indicates more like 65C internal).

Fiddling with the bypass, it seems to start shunting big time at a bit
under 0.4bar - so I have set it a smidge over.

The plan is now to turn the boiler down to about 55C flow - I have
oversized the rads as far as possible with a low flow temperature (and
spare in a really cold winter) in mind.

Think I'll have to go around one more time in a couple of weeks.

Next problem - it's bloody hot upstairs and there are no radiators.

But there is about 50-70m of exposed pipework!!!

It's been quite tightly run (linked Talon clips) and I cannot get 13mm
thick insulation on it. So I'm off to peruse the Internet for either
some thinner tube, or I'll have to box it in (and be damned if the flow
heats the return a bit).

Overall - very happy. I have boiled everyone half to death running it
flat out all day. That is very nice - this house has never been this warm :)

[John Rumm]

On 11/11/2017 18:31, Tim Watts wrote:

> Overall - very happy. I have boiled everyone half to death running it
> flat out all day. That is very nice - this house has never been this
> warm :)

Yup its surprising how you notice heat after a long spell without!

I grew up in place that did not have CH until I was about 17ish.

Getting up on a winter's morning to go to college was a well honed
routine - kettle would boil on a time switch. Chuck water in mug left
waiting from the night before with coffee and milk in it, and turn on
the gas fire in bedroom, before leaping back into bed. Drink coffee and
wait for room to become slightly habitable while marvelling at the
frozen condensation on the inside of the windows!

Then one day I came back up in the evening, and the installers had the
new CH fired up, and the place was warm in winter for the first time ever!

[Tim Watts]

On 12/11/17 03:46, John Rumm wrote:
> On 11/11/2017 18:31, Tim Watts wrote:
>
>> Overall - very happy. I have boiled everyone half to death running it
>> flat out all day. That is very nice - this house has never been this
>> warm :)
>
> Yup its surprising how you notice heat after a long spell without!
>
> I grew up in place that did not have CH until I was about 17ish.
>
> Getting up on a winter's morning to go to college was a well honed
> routine - kettle would boil on a time switch. Chuck water in mug left
> waiting from the night before with coffee and milk in it, and turn on
> the gas fire in bedroom, before leaping back into bed. Drink coffee and
> wait for room to become slightly habitable while marvelling at the
> frozen condensation on the inside of the windows!

Sounds like my bedroom in Reading, rented off an old polish bloke:

3kW fan heater on timeswitch. Coin meter ran out and I reckon the dT/dt
was about 1C/min!

[Tim Watts]

On an aside:

Very pleased that my calculations seem to have borne out.

This is my spreadsheet:

https://drive.google.com/open?id=1fWOVvFMhbR4i8WAA_pWRCGHjqxguvxZKXpMbXX-PTdk

I tried to design the biggest radiators in that I could, without taking
up excessive space. It was nice to have a clean sheet... PS the rad
prices were less via the plumber's discount and over half of the costs
were labour, so in the grand scheme of things not too bad.

Today, Heat Genius showed the kitchen/dining room (a difficult room to
heat - large, 2 big bay windows, no door to side lobby) went from

18.4C at 6am to
20.5C at 7am

with a *flow* temperature (external to boiler) of around 55C - that
would be the green column H on the sheet, delta-T=30K

Sadly the WB boilers do not have a simple weather compensation option
(they want you to use their smart programmer to get that and that
doesn't work with an external programmer) - so we're pretty much in the
land of twiddling the knob each month.

However, I'm hoping to reduce that to a simple guide on the boiler -
Novemeber - position 4, January - 5 or 6, or something like that...

[Tim Watts]

On 12/11/17 10:55, Tim Watts wrote:
> On an aside:

On a further aside:

I am *very* impressed with the heat output of Ultraheat Tibrook vertical
rads: (Ultraheat were recommended here last time I asked):


http://www.ultraheat.co.uk/premier-range/tilbrook.html

These have been used in a few difficult locations where there was simply
no long run of wall available for a normal rad.

They're baffled at the bottom forcing water to flow up one half and back
down the other half (disadvantage, only bottom entry pipework is
allowed) - seems to work.

The rest, I used Quinn Compact - a normal typical radiator, but heat
outputs for any given configuration are better than competitors. Plus
they are made in Wales with British steel so +1 for home production.

[Tim Watts]

Towel rail:

Was warned by plumbers to avoid chrome plated.

So went for https://www.screwfix.com/p/a/28451
which is stainless. Looks the same and the miserable amount of heat it
throws off (it's purpose is for drying the bath towel) surprisingly
seems to keep the bathroom warm (islanded, no external walls)

[T i m]

On Sat, 11 Nov 2017 16:59:53 +0000, John Rumm
<see.my.s...@nowhere.null> wrote:

>On 11/11/2017 11:44, Tim Watts wrote:
>> I've balancing my new CH - noticed the flow and return to the boiler
>> were virtually the same - and the auto bypass valve was set to minimum
>> (0.1 bar = 1m head water IIRC)
>>
>> Closing it down to 0.4 bar has jumped the differential temperature - but
>> I suspect that's too high.
>>
>> The Worcester manual says the pump can deliver 2m head for "21C
>> temperature rise" - nothing else about min flow rates or bypass pressure.
>>
>> Any ideas? If I turn it to 0.2bar the flow temperature starts to creep up.
>>
>> Now this may also suggest I have the lockshields all turned down too low
>> as well (I've opened 1/4 - 3/4 turn as a starting point).
>
>
>I have mine set pretty high - based on the assumption that I only want
>it to do anything when nearly all the TRVs are closed off. A highish
>differential temperature should keep condensing efficiency up as well.

Never actually having CH of my own [1] and only dabbling with other
peoples when helping them out, I am not up to speed on all the rules
re 'balancing' the system, especially on something like a combi /
sealed system.

I have a question / interest though because I was round my mates the
other day when they had the plumbers in because they didn't have any
hot water.

I had previously been told they had the gas boiler AND immersion on
because there were 4 of them showering every morning and the hw would
run out otherwise?

Anyway, I while back (a couple of years possibly) I had helped them
(over the phone) conclude that the immersion had probably gone as it
tripped the ELCB in the CU when you turned it on and I thought it had
been replaced (but it may have and had gone again)?

Anyroadup, the plumbers this time had previously replaced a motorised
valve (apparently, a couple of weeks earlier) and they thought it had
gone again (faulty) but then found a valve marked up 'Balance, do not
touch' that they had been completely turned off and opening it, seemed
to have fixed the problem?

Now the only time I was aware of a bypass was in the two way motorised
valves where when both were off you could potentially short out the
boiler so a 15mm pipe was placed in parallel with the HW cylinder and
before the mv to ensure there was always a path back to the boiler (or
somesuch)?

So, my question is 'could it be possible that a 'balance valve' is
likely to be (nearly) fully closed and for it to be right' please? I'm
asking in case the plumber doing what they did is not a real solution
and it will cause issues further down the line?

FWIW they have a fairly big HW cylinder and a mix of UF and
conventional radiator CH.

Cheers, T i m

[1] I did actually have the boiler and cylinder fitted here but then
my Uncle's coal fired floor standing CH failed so I took my stuff out
and fitted it (and some more rads) in his. In fact, because it was a
'low capacity' wall mounted boiler with a copper heat exchanger I also
fitted delayed stop relay to the pump and seemed to make the system
run very well (and never went wrong once in probably ~20 years). ;-)

[Tim Watts]

It could be a shunt. Normally you use a designated radiator. Or if you
don't want to (or don't trust it not to be fiddled with), you could do
as I did and put a pressure bypass in, which should only open to protect
the boiler pump.

[T i m]

On Sun, 12 Nov 2017 12:41:34 +0000, Tim Watts <tw_u...@dionic.net>
wrote:

<snip>

>> Anyroadup, the plumbers this time had previously replaced a motorised
>> valve (apparently, a couple of weeks earlier) and they thought it had
>> gone again (faulty) but then found a valve marked up 'Balance, do not
>> touch' that they had been completely turned off and opening it, seemed
>> to have fixed the problem?
>>
>> Now the only time I was aware of a bypass was in the two way motorised
>> valves where when both were off you could potentially short out the
>> boiler so a 15mm pipe was placed in parallel with the HW cylinder and
>> before the mv to ensure there was always a path back to the boiler (or
>> somesuch)?
>>
>> So, my question is 'could it be possible that a 'balance valve' is
>> likely to be (nearly) fully closed and for it to be right' please? I'm
>> asking in case the plumber doing what they did is not a real solution
>> and it will cause issues further down the line?
>
>It could be a shunt.

As I describe above (but with some control)?

>Normally you use a designated radiator.

So this would be on all the time, no stat-valve etc?

>Or if you
>don't want to (or don't trust it not to be fiddled with), you could do
>as I did and put a pressure bypass in, which should only open to protect
>the boiler pump.

Ah, that makes more sense and as you eluded to above, less chance of
being 'fiddled with'.

It will be interesting to see how it all went on Friday (when the
plumbers were due back to replace both motorised valves) and whilst
they were there the other day I overheard talk of 'one of the
motorised valves not being moveable by hand' ... but are they all (as
they could have been different makes / designs)?

Cheers, T i m

[Roger Hayter]

My WB Greenstar oil boiler has two ways to do weather compensation.
Either via a fancy controller or via a separate sensor (plastic case,
choc block connector, one thermistor, not even a PCB, 26GBP!) with it's
own dedicated terminals on the boiler. Are you sure yours can't do it
that way?


--

Roger Hayter

[Tim Watts]

On 12/11/17 13:05, T i m wrote:
> On Sun, 12 Nov 2017 12:41:34 +0000, Tim Watts <tw_u...@dionic.net>

>> Normally you use a designated radiator.
>
> So this would be on all the time, no stat-valve etc?

Yes.

And with lockshield valves both ends so normal users don't fiddle.

>> Or if you
>> don't want to (or don't trust it not to be fiddled with), you could do
>> as I did and put a pressure bypass in, which should only open to protect
>> the boiler pump.
>
> Ah, that makes more sense and as you eluded to above, less chance of
> being 'fiddled with'.
>
> It will be interesting to see how it all went on Friday (when the
> plumbers were due back to replace both motorised valves) and whilst
> they were there the other day I overheard talk of 'one of the
> motorised valves not being moveable by hand' ... but are they all (as
> they could have been different makes / designs)?

Usually they have an override lever that can be pushed and dropped into
a locking slot, for when the motor fails.

[Tim Watts]

No - I read the installer's manual and rang WB tech. They also confirmed
that the CDi fancy "Wave" IIRC programmer could not accept an external
control input - so not very fancy.

[Roger Hayter]

That's a shame, I thought that it was one of the big selling points of
condensing boilers that you could do this. Not that there appears to be
any choice about getting a condensing boiler! I suppose an alternative
would be to adjust the flow temperature according to the return
temperature, but it probably varies too rapidly for this to work. How
does the fancy controller do it without any external informaion? One
thing I don't think is common in oil boilers is modulation of heat
ouput, It would I think be dfficult to achieve without multiple burners.
I don't know how modulation in gas boilers is controlled without
external temperature - speed of temperature rise or something?





--

Roger Hayter

[T i m]

On Sun, 12 Nov 2017 13:48:20 +0000, Tim Watts <tw_u...@dionic.net>
wrote:

>On 12/11/17 13:05, T i m wrote:
>> On Sun, 12 Nov 2017 12:41:34 +0000, Tim Watts <tw_u...@dionic.net>
>
>
>>> Normally you use a designated radiator.
>>
>> So this would be on all the time, no stat-valve etc?
>
>Yes.
>
>And with lockshield valves both ends so normal users don't fiddle.

Check.
>
<snip>

>> It will be interesting to see how it all went on Friday (when the
>> plumbers were due back to replace both motorised valves) and whilst
>> they were there the other day I overheard talk of 'one of the
>> motorised valves not being moveable by hand' ... but are they all (as
>> they could have been different makes / designs)?
>
>Usually they have an override lever that can be pushed and dropped into
>a locking slot, for when the motor fails.

That's what I remember from seeing other peoples systems but I wasn't
sure if it was always the case?

eg, Can you (could you) 'commonly' get a motorised valve where you
can't override it manually? If the answer is 'no', then one that
wouldn't move with the lever was very likely to be stuck?

Cheers, T i m

[Johnny B Good]

I believe the primary purpose of the locking lever is to force the 3
port diverter valve to keep both ports open to facilitate draining and
reduce air locks during refilling operations whilst the system is powered
down.

It doesn't (or shouldn't) stay in the latched position once the system
is powered up and running. I can't say whether this also applies to the
two port valves since I only have experience of the 35 yo single 3 port
diverter valve (Y or S plan ?) setup used here.

--
Johnny B Good

[John Rumm]

On 12/11/2017 14:02, Roger Hayter wrote:
> Tim Watts <tw_u...@dionic.net> wrote:


>> No - I read the installer's manual and rang WB tech. They also confirmed
>> that the CDi fancy "Wave" IIRC programmer could not accept an external
>> control input - so not very fancy.
>
> That's a shame, I thought that it was one of the big selling points of
> condensing boilers that you could do this.

Some you can easily. Others may require a bit more intervention / invention.

You can do stuff with a controlled blending valve on the output of the
boiler, that mixes some of the return flow back into the output before
its gets reheated. (much as some of the UFH mixers do), but in this case
use the external temp to control the mix (when low temps result in less
mixing, and hotter effective flow temps)

> Not that there appears to be
> any choice about getting a condensing boiler!

There are a limited set of cases where you can still legally fit a non
condenser.

> I suppose an alternative
> would be to adjust the flow temperature according to the return
> temperature, but it probably varies too rapidly for this to work. How
> does the fancy controller do it without any external informaion?

In the case of the one on mine, via an external temperature sensor. You
select a response curve on the programmer based on the heat loss
characteristics of the house, and then the programmer picks a flow
temperature on that curve based on the current external (and possibly
current internal) temperature.

> One
> thing I don't think is common in oil boilers is modulation of heat
> ouput, It would I think be dfficult to achieve without multiple burners.

IIUC modern oil boilers do support *some* modulation - but not nearly as
wide a range as with gas ones.

> I don't know how modulation in gas boilers is controlled without
> external temperature - speed of temperature rise or something?

Usually based on the return temperature and the flow set point
temperature. As they start to see the return temp start to rise toward
the flow temp, they modulate the power down so as not to exceed the flow
maximum set temp. If they reach minimum power output and still the
return temp is too close to the flow, then they cycle off much like a
fixed output boiler would on its stat.

[John Rumm]

On 12/11/2017 15:15, Johnny B Good wrote:
> On Sun, 12 Nov 2017 13:48:20 +0000, Tim Watts wrote:
>
>> On 12/11/17 13:05, T i m wrote:
>>> On Sun, 12 Nov 2017 12:41:34 +0000, Tim Watts <tw_u...@dionic.net>
>>
>>
>>>> Normally you use a designated radiator.
>>>
>>> So this would be on all the time, no stat-valve etc?
>>
>> Yes.
>>
>> And with lockshield valves both ends so normal users don't fiddle.
>>
>>>> Or if you don't want to (or don't trust it not to be fiddled with),
>>>> you could do as I did and put a pressure bypass in, which should only
>>>> open to protect the boiler pump.
>>>
>>> Ah, that makes more sense and as you eluded to above, less chance of
>>> being 'fiddled with'.
>>>
>>> It will be interesting to see how it all went on Friday (when the
>>> plumbers were due back to replace both motorised valves) and whilst
>>> they were there the other day I overheard talk of 'one of the motorised
>>> valves not being moveable by hand' ... but are they all (as they could
>>> have been different makes / designs)?
>>
>> Usually they have an override lever that can be pushed and dropped into
>> a locking slot, for when the motor fails.
>
> I believe the primary purpose of the locking lever is to force the 3
> port diverter valve to keep both ports open to facilitate draining and
> reduce air locks during refilling operations whilst the system is powered
> down.

Yup. On many it does not activate the microswitch in the same way normal
activation would - so does not provide a temporary fix for all ills.

> It doesn't (or shouldn't) stay in the latched position once the system
> is powered up and running. I can't say whether this also applies to the
> two port valves since I only have experience of the 35 yo single 3 port
> diverter valve (Y or S plan ?) setup used here.

Yup two port ones have a similar feature (or at least the Honeywell ones do)

[T i m]

On Mon, 13 Nov 2017 14:23:56 +0000, John Rumm
<see.my.s...@nowhere.null> wrote:

>On 12/11/2017 15:15, Johnny B Good wrote:

<snip>

>> It doesn't (or shouldn't) stay in the latched position once the system
>> is powered up and running. I can't say whether this also applies to the
>> two port valves since I only have experience of the 35 yo single 3 port
>> diverter valve (Y or S plan ?) setup used here.
>
>Yup two port ones have a similar feature (or at least the Honeywell ones do)

So that's 'the two port ones *can* have a similar feature ...' as
that is my question ... are we assured that all makes and models do?

The point was that if someone was expecting some form of manual
control and thought they saw one, but it didn't move, does that alone
guarantee that the valve was faulty / stuck, or could there be some
valves that simply couldn't be overridden manually or can only be
overridden in one direction or some other conditions(s) etc?

I'm not expecting a definitive answer from anyone in particular, just
putting the question out there as a definitive answer may suggest my
friend is being 'duped' by the plumber ... ;-(

Cheers, T i m

[John Rumm]

On 13/11/2017 15:59, T i m wrote:
> On Mon, 13 Nov 2017 14:23:56 +0000, John Rumm
> <see.my.s...@nowhere.null> wrote:
>
>> On 12/11/2017 15:15, Johnny B Good wrote:
> <snip>
>
>>> It doesn't (or shouldn't) stay in the latched position once the system
>>> is powered up and running. I can't say whether this also applies to the
>>> two port valves since I only have experience of the 35 yo single 3 port
>>> diverter valve (Y or S plan ?) setup used here.
>>
>> Yup two port ones have a similar feature (or at least the Honeywell ones do)
>
> So that's 'the two port ones *can* have a similar feature ...' as
> that is my question ... are we assured that all makes and models do?

Not having seen all of them, I can't answer.

> The point was that if someone was expecting some form of manual
> control and thought they saw one, but it didn't move, does that alone
> guarantee that the valve was faulty / stuck, or could there be some
> valves that simply couldn't be overridden manually or can only be
> overridden in one direction or some other conditions(s) etc?

I would expect that of someone was suggesting the valve were "stuck",
they would not be talking about the manual leaver. In these situations
is more common to take the motor head right off, and see if the spindle
sticking out of the top of the wet bit will turn (with pliers and
lubrication etc). If its seized, then replacement of the wet part
becomes necessary.

> I'm not expecting a definitive answer from anyone in particular, just
> putting the question out there as a definitive answer may suggest my
> friend is being 'duped' by the plumber ... ;-(

[T i m]

On Mon, 13 Nov 2017 16:46:26 +0000, John Rumm

<see.my.s...@nowhere.null> wrote:

>On 13/11/2017 15:59, T i m wrote:
>> On Mon, 13 Nov 2017 14:23:56 +0000, John Rumm
>> <see.my.s...@nowhere.null> wrote:
>>
>>> On 12/11/2017 15:15, Johnny B Good wrote:
>> <snip>
>>
>>>> It doesn't (or shouldn't) stay in the latched position once the system
>>>> is powered up and running. I can't say whether this also applies to the
>>>> two port valves since I only have experience of the 35 yo single 3 port
>>>> diverter valve (Y or S plan ?) setup used here.
>>>
>>> Yup two port ones have a similar feature (or at least the Honeywell ones do)
>>
>> So that's 'the two port ones *can* have a similar feature ...' as
>> that is my question ... are we assured that all makes and models do?
>
>Not having seen all of them, I can't answer.

No, quite, it was just the possibility / chance I was talking about.
;-)

>
>> The point was that if someone was expecting some form of manual
>> control and thought they saw one, but it didn't move, does that alone
>> guarantee that the valve was faulty / stuck, or could there be some
>> valves that simply couldn't be overridden manually or can only be
>> overridden in one direction or some other conditions(s) etc?
>
>I would expect that of someone was suggesting the valve were "stuck",
>they would not be talking about the manual leaver.

Ok ...

>In these situations
>is more common to take the motor head right off, and see if the spindle
>sticking out of the top of the wet bit will turn (with pliers and
>lubrication etc). If its seized, then replacement of the wet part
>becomes necessary.

Ah, so the manual lever isn't actually a manual lever but a manually
operated switch to override the timer / controller electrical input?

>
>> I'm not expecting a definitive answer from anyone in particular, just
>> putting the question out there as a definitive answer may suggest my
>> friend is being 'duped' by the plumber ... ;-(

The issues seemed to be (from what I was overhearing from the
plumbers) was the possibility that the 'new valve' they had fitted
previously (days / weeks before) wasn't working properly but I also
heard them saying to the householder that they 'weren't electricians'
so I questioned (in my head) just how much they knew about any of it?
;-(

Maybe they were just plumbers and what my friends needed was 'Heating
engineers'?

Time will tell etc. ;-)

Cheers, T i m

[Johnny B Good]

When I was looking to fix the problem of the 1st floor radiators warming
up when hot water only was called for some two or three years ago, I was
initially looking at prices for a complete 3 port Honeywell valve
assembly around the 150 quid mark.

After a bit of researching, I discovered that I could retain the
expensive brass part of the valve body by upgrading the all in one motor/
valve plate to a modern (post 1982!) two part motor and valve plate that
would allow any future motor head problems to be fixed without the need
for a drain down. I got the valve plate from, I think, my local Plumb
Centre[1] and a modern detachable motor head from Tool Station in the end
for just under 70 quid all in.

One thing that tripped me up was testing the motor head in isolation
from the valve plate spindle which revealed a slipping gears problem. It
was only *after* experiencing the same "fault" with the replacement from
Tool Station that it finally dawned on me that it was the lack of support
to the final sector cog normally provided by the valve spindle and the
only thing that had been at fault was my testing technique.

I felt so bad about returning a fully functioning part as being faulty
that I went back to Tool Station, with the second motor unit in hand,
just to apologise and explain my mistake to the very accommodating sales
member who had dealt with my returned "faulty" motor head just so he
could know that there hadn't been anything wrong with the original part
in the first place.

Compared to Screwfix, the Tool Station counter staff are a joy to deal
with so I felt I owed them the courtesy of an apology. Besides which, TS
prices are generally lower than SF's prices so yet another reason to show
due respect.

[1] That was my first port of call because I had hopes of being able to
cannibalise the rubber ball to replace the hardened and misshapen one in
the original unit which had been the root cause of the problem. Only then
did it become clear that I'd need to buy yet another part, a compatible
motor head unit before I could complete the repair.

I think the valve plate was around 23 quid in all with, to my surprise,
Tool Station proving to be the cheapest source of a compatible motor head
at a mere 45 quid or so compared to on line sources quoting 65 quid or
more.

And, whilst I remember, the only other expense involved was the 4 quid
spent on the purchase of a 39mm AF open ended chrome vanadium spanner
from a second hand tool store my missus had insisted was no longer in
business (such insistence resulting in a fruitless search via a 22 mile
round trip to the next town's market) to grip the flats of the Honeywell
3 port valve body. Thanks to the upgrade to a modern two piece motor head/
valve plate, a tool I may never use again in anger to repair the central
heating system in my lifetime.

Thank goodness it was only a mere 4 quid! In all honesty, I think it's
more likely to see service as a defensive weapon kept under the bed for
use against night time intruders than as a plumbing tool.

--
Johnny B Good

[John Rumm]

On 13/11/2017 22:19, T i m wrote:
> On Mon, 13 Nov 2017 16:46:26 +0000, John Rumm
> <see.my.s...@nowhere.null> wrote:
>
>> On 13/11/2017 15:59, T i m wrote:
>>> On Mon, 13 Nov 2017 14:23:56 +0000, John Rumm
>>> <see.my.s...@nowhere.null> wrote:

>> I would expect that of someone was suggesting the valve were "stuck",
>> they would not be talking about the manual leaver.
>
> Ok ...
>
>> In these situations
>> is more common to take the motor head right off, and see if the spindle
>> sticking out of the top of the wet bit will turn (with pliers and
>> lubrication etc). If its seized, then replacement of the wet part
>> becomes necessary.
>
> Ah, so the manual lever isn't actually a manual lever but a manually
> operated switch to override the timer / controller electrical input?

No, its a leaver that moves the gearbox mechanism through some of its
normal travel - usually enough to move the valve position, but not
always enough to bump into the micro switches at the end of the normal
motorised travel (and which would be required to fire the boiler with
the conventional wiring plan).

Its possible for the gearbox or motor to fail, or simply be unable to
exert enough force to turn the spindle (either at all, or far enough).
In many cases, adding some lubrication to the spindle and working it
back and forth with pliers etc will free it enough to work normally after.

>>
>>> I'm not expecting a definitive answer from anyone in particular, just
>>> putting the question out there as a definitive answer may suggest my
>>> friend is being 'duped' by the plumber ... ;-(
>
> The issues seemed to be (from what I was overhearing from the
> plumbers) was the possibility that the 'new valve' they had fitted
> previously (days / weeks before) wasn't working properly but I also
> heard them saying to the householder that they 'weren't electricians'
> so I questioned (in my head) just how much they knew about any of it?
> ;-(
>
> Maybe they were just plumbers and what my friends needed was 'Heating
> engineers'?
>
> Time will tell etc. ;-)

[T i m]

On Tue, 14 Nov 2017 02:57:32 +0000, John Rumm
<see.my.s...@nowhere.null> wrote:

<snip>

>> Ah, so the manual lever isn't actually a manual lever but a manually
>> operated switch to override the timer / controller electrical input?
>
>No, its a leaver that moves the gearbox mechanism through some of its
>normal travel - usually enough to move the valve position, but not
>always enough to bump into the micro switches at the end of the normal
>motorised travel (and which would be required to fire the boiler with
>the conventional wiring plan).

Ah, thanks.

>
>Its possible for the gearbox or motor to fail, or simply be unable to
>exert enough force to turn the spindle (either at all, or far enough).

(We have that now and again with the electric curtains where the track
gets damp and the current limit trips before the max travel).

>In many cases, adding some lubrication to the spindle and working it
>back and forth with pliers etc will free it enough to work normally after.

Yeah, been there and done that with enough stuff over my life, the
last being a mates mates motorcycle rear drum brake lever that was
actually seizing up. He was going to just spray it with WD40 (that may
have worked, especially short time) but I recommended we 'do it
properly'. So we removed the rear wheel, stripped the brake drum,
cleaned and *re-greased* the lever and replaced the missing O ring /
seal.

Probably not so easy or appropriate to replicate on a valve full of
water though. ;-(


Cheers, T i m