Glugging Noise/CH Pump
Maxine Evans
heating pump? I am asking because I have had a problem that has been
occuring for nearly 2 years now and this is just about the last thing left.
We've had the boiler manufacturers and the installer out about 30 times and
both say there is nothing wrong with the boiler or the installation.
However, both agree that the noise is a serious problem!!
PROBLEM: We are getting a backwash-type glugging noise (similar to a toilet
flush!!) that is created near or by the pump. Sometimes this is a huge glug
that lasts for many seconds and happens frequently, and at other times it
can be quiet for ages. It nearly always happens when the boiler has reached
temperature and has just cycled off, but can happen at any time. It is worse
on higher pump speeds and also happens more frequently when the boiler is on
higher temperature settings.
SYSTEM: We have pumped central heating and gravity fed hot water. The
boiler is 9 months old and is a Potterton Profile 80e - fed via a feed &
expansion cistern in the loft. We have 9 radiators (all new) and a towel
rail (original) on the gravity circuit. The pump is a 3-speed Grundfos and
is currently on the lowest setting, as higher settings make the problem much
worse.
SOLUTIONS: About a month ago we put Fernox cleanser in to circulate, flushed
the system through and followed this with Fernox inhibitor in the hope that
it might quieten things down - all to no avail. Prior to that we've had
lots of pipework altered, a new pump, more cleanser & inhibitor, the boiler
replaced under warantee (this is the 2nd new boiler in 2 years), the hot
water cylinder has been raised, automatic bleed valves installed - nothing
has worked. We don't get any air in the radiators and the F&E cistern seems
to be working properly.
If it helps, we did have problems with 2 downstairs radiators after flushing
the system and refilling. They were full of water, but stayed absolutely
stone cold when the rest were fully hot. Although there was definitely no
air in them, we "bled" a substantial amount of water from them and they got
hot and have stayed hot ever since. Could the problem with the pump lie
with these 2 radiators? I think that they are the last in line to the
boiler, but am not 100% sure. I am sure however, that the radiators aren't
as hot as they should be. With the pump on 2, they are about right -
however, the glugging noise is terrible with the pump on 2, so we have to
keep it on 1 for the sake of our sanity!!
So, back to my original question, could an incorrectly balanced system cause
a glugging noise in or around the pump? If not, has anyone got an idea as
to what could be? We have been considering converting to a fully pumped
system, but I am worried that this will only double the trouble and cause
problems with the hot water system as well. I am absolutely desperate for a
solution!!!!
Any advice would be greatly appreciated.
Thank you very much for your help.
Kind regards,
Maxine Evans.
gARY
<max...@evans155.freeserve.co.uk> wrote:
>
>Can an incorrectly balanced system cause noise problems with a central
>heating pump?
No.
>If it helps, we did have problems with 2 downstairs radiators after
>flushing the system and refilling. They were full of water, but stayed
>absolutely stone cold when the rest were fully hot. Although there was
>definitely no air in them, we "bled" a substantial amount of water from
>them and they got hot and have stayed hot ever since. Could the problem
>with the pump lie with these 2 radiators? I think that they are the last
>in line to the boiler, but am not 100% sure. I am sure however, that the
>radiators aren't as hot as they should be. With the pump on 2, they are
>about right -however, the glugging noise is terrible with the pump on 2,
You have got air in the pipes! these two radiators must have the air screws
removed (one at a time) and use a bucket to collect the gushing water after
shuting off one of the rad valves and then do the same with the other valve
after another bucket of water, do this until air comes out or air is pushed
into another radiator along the line (the only way to check that the latter
has happend is to bleed the other rads), air block trapped in a pipe between
the pump and these rads . Make sure the heating water is cold of course :)
>I am absolutely desperate for a solution!!!!
>
>Any advice would be greatly appreciated.
>Thank you very much for your help.
>Kind regards,
>Maxine Evans.
--
gARY
Email=> Change "uk.co" to "co.uk".
Site => http://www.JustServices.com/
Simon Rance
>Can an incorrectly balanced system cause noise problems with a central
>heating pump?
>PROBLEM: We are getting a backwash-type glugging noise (similar to a
toilet
>flush!!) that is created near or by the pump. Sometimes this is a huge
glug
>that lasts for many seconds and happens frequently, and at other times it
>can be quiet for ages. It nearly always happens when the boiler has reached
>temperature and has just cycled off, but can happen at any time. It is
worse
>on higher pump speeds and also happens more frequently when the boiler is
on
>higher temperature settings.
>The pump is a 3-speed Grundfos and
>is currently on the lowest setting, as higher settings make the problem
much
>worse.
>If it helps, we did have problems with 2 downstairs radiators after
flushing
>the system and refilling. They were full of water, but stayed absolutely
>stone cold when the rest were fully hot. Although there was definitely no
>air in them, we "bled" a substantial amount of water from them and they got
>hot and have stayed hot ever since. Could the problem with the pump lie
>with these 2 radiators? I think that they are the last in line to the
>boiler, but am not 100% sure. I am sure however, that the radiators aren't
>as hot as they should be. With the pump on 2, they are about right -
>keep it on 1 for the sake of our sanity!!
This sounds like cavitation caused by water boiling in the suction of the
pump (I work in the chemicals industry, and it is a common problem when
pumping volatile hydrocarbons near their boiling point) - is the pump by any
chance in the loft or somewhere else near to the top of the system? This may
make things worse.
The technical term for what drives the problem is Net Positive Suction
Head - you need enough pressure at the pump suction to stop whatever it is
you are pumping from boiling (much the same principle as a pressure cooker).
If the problem is due to cavitation, reducing pump speed or boiler
temperature should help, but it may be that doing both means your house
isn't as warm as you'd like it to be!
It *could* be due to balancing, in that if the lockshield valves (the ones
on the rad. outlets) are too far closed, there is too much pressure drop
around the loop. Try opening the lockshields on the two rads. you mention,
maybe a half-turn at a time (keep an note of how far you turn them in case
you change your mind!)
Many systems have a 15mm recirculation line (or kickback) around the pump
(ie. from the discharge back to the inlet), with a gate valve in it which
you can adjust to reduce the loop pressure drop until the system quietens
down (this is a bit of a black art) - if you don't have a bypass, I would
suggest fitting one - it should not be particularly expensive.
Last inute thought: if you have thermostatic rad. valves fitted on ALL
rads., you can sometimes dead-head the pump - you need one or two without
to maintain a flow!
Hope this helps.
Simon Rance
John
Maxine Evans wrote in message
<7ccmps$kn0$1...@news4.svr.pol.co.uk>...
>Can an incorrectly balanced system cause noise problems
with a central
that has been
>occuring for nearly 2 years now and this is just about
the last thing left.
>We've had the boiler manufacturers and the installer
out about 30 times and
>both say there is nothing wrong with the boiler or the
installation.
>However, both agree that the noise is a serious
problem!!
>
(similar to a toilet
>flush!!) that is created near or by the pump.
Sometimes this is a huge glug
>that lasts for many seconds and happens frequently, and
at other times it
>can be quiet for ages. It nearly always happens when
the boiler has reached
>temperature and has just cycled off, but can happen at
any time. It is worse
>on higher pump speeds and also happens more frequently
when the boiler is on
>higher temperature settings.
Balancing is VERY UNLIKELY to have any bearing on your
problem
>
>SYSTEM: We have pumped central heating and gravity fed
hot water. The
>boiler is 9 months old and is a Potterton Profile 80e -
fed via a feed &
>expansion cistern in the loft. We have 9 radiators
(all new) and a towel
>rail (original) on the gravity circuit. The pump is a
3-speed Grundfos and
>is currently on the lowest setting, as higher settings
make the problem much
>worse.
Does the pump push water away from the boiler (pumped
flow) or does it draw it back from the radiators to the
boiler? (pumped return)
>
>SOLUTIONS: About a month ago we put Fernox cleanser in
to circulate, flushed
>the system through and followed this with Fernox
inhibitor in the hope that
>it might quieten things down - all to no avail. Prior
to that we've had
>lots of pipework altered, a new pump, more cleanser &
inhibitor, the boiler
>replaced under warantee (this is the 2nd new boiler in
2 years),
Since Potterton don't usually replace boilers simply
because they are noisy can you tell us WHY they replaced
yours - did you by any chance suffer a leaking unit and
does your comment 2nd new boiler mean you have had one
new one plus one replacement or have you had the new
boiler replaced twice i.e. three boilers all together?
> the hot
>water cylinder has been raised, automatic bleed valves
installed - nothing
>has worked. We don't get any air in the radiators and
the F&E cistern seems
>to be working properly.
How high above the pump is the F&E tank?
>
>If it helps, we did have problems with 2 downstairs
radiators after flushing
>the system and refilling. They were full of water, but
stayed absolutely
>stone cold when the rest were fully hot. Although
there was definitely no
>air in them, we "bled" a substantial amount of water
from them and they got
>hot and have stayed hot ever since. Could the problem
with the pump lie
>with these 2 radiators? I think that they are the last
in line to the
>boiler, but am not 100% sure. I am sure however, that
the radiators aren't
>as hot as they should be. With the pump on 2, they are
about right -
>however, the glugging noise is terrible with the pump
on 2, so we have to
>keep it on 1 for the sake of our sanity!!
I suspect there may be a restriction in the pipes which
feed these two radiators either in the form of a partial
airlock (bubble of air trapped in a bend or kink in your
pipes OR you have a section of pipe with a partial
blockage of sludge. Try shutting off both valves on each
rad, disconnecting the rad, connecting a hose to the
valve and passing the other end into a big bucket or a
drain. Turn on the valve and fast flush about a gallon
or two through. Then restore as previous. When you are
satisfied about the pipes being clear then you can read
up in the FAQ and balance your system, however if there
are TRVs on some rads there isn't any point in going mad
about balancing try initially setting each lockshield
valve at about 3/4 turn open and progress from there
>
>So, back to my original question, could an incorrectly
balanced system cause
>a glugging noise in or around the pump? If not, has
anyone got an idea as
>to what could be? We have been considering converting
to a fully pumped
>system, but I am worried that this will only double the
trouble and cause
>problems with the hot water system as well. I am
absolutely desperate for a
>solution!!!!
I strongly suspect that you have either or both an air
weep on the suction side of the pump and/or the pump is
pulling water back from the radiators to the boiler and
causing sub-atmospheric pressure in parts of your
heating system, drawing a little air in which then
seperates out again in the boiler and passes up the open
vent and out of the system. Some of the air will
dissolve in the water and the dissolved oxygen will
corrode your system internally creating black sludge
which may account for your poor flow to the two rads you
mentioned. This can occasionally happen with a pump on
the flow if the head tank is not high enough above the
pump as well but pumped return is the most common cause.
>
>Any advice would be greatly appreciated.
>Thank you very much for your help.
>Kind regards,
>Maxine Evans.
>
>
>
Please try out the advice above and come back to us with
the data asked for
--
Please note antispam measures - do not hit reply
Warning to Spammers - I ALWAYS complain to your ISP
Regards,
John
Maxine Evans
>This sounds like cavitation caused by water boiling in the suction of the
>pump (I work in the chemicals industry, and it is a common problem when
>pumping volatile hydrocarbons near their boiling point) - is the pump by
any
>chance in the loft or somewhere else near to the top of the system? This
may
>make things worse.
No, the pump is at the lowest part of the system by the boiler on the ground
floor. We were having trouble with "kettling" - water boiling in the
boiler. Is this cavitation or a form of it?? This has improved somewhat
since we cleansed the system and added inhibitor, but I have a feeling that
it will be back
with a vengeance.
>If the problem is due to cavitation, reducing pump speed or boiler
>temperature should help, but it may be that doing both means your house
>isn't as warm as you'd like it to be!
This is the trouble, the pump is already on the lowest setting and turning
the
boiler down means the house is no where near warm enough.
>It *could* be due to balancing, in that if the lockshield valves (the ones
>on the rad. outlets) are too far closed, there is too much pressure drop
>around the loop. Try opening the lockshields on the two rads. you mention,
>maybe a half-turn at a time (keep an note of how far you turn them in case
>you change your mind!)
I'm pretty sure that our upstairs radiators had to be closed off quite a lot
so that the downstairs ones could get hot. Perhaps they've been shut off too
much?? I'll give it a go and let you know how it goes.
>Many systems have a 15mm recirculation line (or kickback) around the pump
>(ie. from the discharge back to the inlet), with a gate valve in it which
>you can adjust to reduce the loop pressure drop until the system quietens
>down (this is a bit of a black art) - if you don't have a bypass, I would
>suggest fitting one - it should not be particularly expensive.
We haven't got a bypass in our system and this will definitely be a
consideration if the balancing doesn't work.
>Last inute thought: if you have thermostatic rad. valves fitted on ALL
>rads., you can sometimes dead-head the pump - you need one or two without
>to maintain a flow!
We have TRV's fitted to 8 out of 9 radiators. Could this still be too many??
Hope this isn't a stupid question, but what do you mean by dead-head the
pump?
Thank you very much for your help,
Kind regards,
Maxine :-))
Maxine Evans
> >Can an incorrectly balanced system cause noise problems with a central
> >heating pump? >No.
Oh well, never mind - I was getting rather desperate!! <g>
>You have got air in the pipes! these two radiators must have the air screws
>removed (one at a time) and use a bucket to collect the gushing water after
>shuting off one of the rad valves and then do the same with the other valve
>after another bucket of water, do this until air comes out or air is pushed
>into another radiator along the line (the only way to check that the latter
>has happend is to bleed the other rads), air block trapped in a pipe
between
>the pump and these rads . Make sure the heating water is cold of course :)
The radiators are now red-hot and so I assume that any blockage has been
cleared now. However, the pump is still making it's lovely noise so if you
have any other thoughts on this matter, I would really appreciate it.
Thank you very much for your help and advice,
Kind regards,
Maxine Evans.
Maxine Evans
>Balancing is VERY UNLIKELY to have any bearing on your
>problem
Oh well, it was just a thought <g>
>Does the pump push water away from the boiler (pumped
>flow) or does it draw it back from the radiators to the
>boiler? (pumped return)
Pumped flow - However, it has also been tried on the return but that didn't
cure the problem either.
>Since Potterton don't usually replace boilers simply
>because they are noisy can you tell us WHY they replaced
>yours.
We've had one new boiler and one replacement - 2 boilers in all. Potterton
replaced the original boiler because the installer had tried everything that
they had suggested to cure the noise i.e. raising the HW cylinder, putting
in automatic bleed valves, cleanser & inhibitor etc. etc. Potterton thought
that we might have a faulty heat exchanger - iron filings left inside?? -
but it was apparently easier to replace the whole boiler. Both Potterton and
the installer agree that something is wrong and that apart from the
possibility of corrosion - it is extremely annoying to listen to! There
weren't any leaks as far as I'm aware.
>How high above the pump is the F&E tank?
The F&E tank is on it's own platform in the loft - as high as it can go, and
the pump is on the ground floor by the boiler - the lowest it can go.
>I suspect there may be a restriction in the pipes which
>feed these two radiators either in the form of a partial
>airlock (bubble of air trapped in a bend or kink in your
>pipes OR you have a section of pipe with a partial
>blockage of sludge.
These radiators are red-hot now - Can I safely assume that any blockage has
been cleared?
>When you are
>satisfied about the pipes being clear then you can read
>up in the FAQ and balance your system, however if there
>are TRVs on some rads there isn't any point in going mad
>about balancing try initially setting each lockshield
>valve at about 3/4 turn open and progress from there.
Does having TRV's mean that balancing isn't *so* important then? Also, does
having too many TRV's have an adverse effect on the system? We have them on
8 of the 9 radiators and I have wondered if this could cause a problem. One
more thing, is there a way to work out what speed the pump should be on? I
have a feeling that it should be on 2 and if so, will the radiator balance
be totally different than when the pump speed is on 1?
>I strongly suspect that you have either or both an air
>weep on the suction side of the pump and/or the pump is
>pulling water back from the radiators to the boiler and
>causing sub-atmospheric pressure in parts of your
>heating system, drawing a little air in which then
>seperates out again in the boiler and passes up the open
>vent and out of the system.
It does sound as though the glug goes backwards through the pump towards the
boiler - as though the pump is drawing water back from the radiators.
If it gives you any clues, the only thing that is pretty consistent about
the noise is that it nearly always occurs just after the boiler cuts out
when it has reached temperature. The boiler clicks off and then almost
immediately we get the glugging - however, it doesn't happen every time.
>This can occasionally happen with a pump on
>the flow if the head tank is not high enough above the
>pump as well but pumped return is the most common cause.
The F&E tank is as high as it can go and the pump is on the flow. Are there
any other reasons for a drop in pressure?
I am really sorry to ask so many questions!! This could turn out to be
quite a lengthy problem, so please feel free to tell me to go away at any
time!!
Thank you very much for your help,
Kind regards,
Maxine :-)
Dave
<max...@evans155.freeserve.co.uk> wrote:
>
> It does sound as though the glug goes backwards through the pump towards
> the
> boiler - as though the pump is drawing water back from the radiators.
>
> If it gives you any clues, the only thing that is pretty consistent about
> the noise is that it nearly always occurs just after the boiler cuts out
> when it has reached temperature. The boiler clicks off and then almost
> immediately we get the glugging - however, it doesn't happen every time.
This sounds as if the boiler is kettling when the pump switches off due to
the thermostat being satisfied, but the boiler still live. A pump overrun
circuit will cure this, I made my own. But I thought most modern systems had
this. Could be it's all down to electrics
--
Dave dave....@NOSPAMargonet.co.uk
(remove NOSPAM to reply)
Nigel Orr
<dave....@NOSPAMargonet.co.uk> wrote:
> This sounds as if the boiler is kettling when the pump switches off due to
>the thermostat being satisfied, but the boiler still live. A pump overrun
>circuit will cure this, I made my own. But I thought most modern systems had
>this. Could be it's all down to electrics
I think this is what is happening in my system- at switch-off time,
there is about a minute of 'gurgles'. I don't see why it should be
worse at switch-off than at any other time- is it because the pump and
gas supply both switch off, but there is still some heat which has not
been transferred to the water, so it boils over? I can't see any
other sensible reason.
So a pump overrun circuit presumably just runs the pump for a minute
or two after the room thermostat is satisfied?
Wouldn't the same problem arise when the boiler is on for water
heating only? It reaches maximum temperature, its thermostat cuts
off, but more heat goes into the water? Is the solution to run the
pump for a minute every time the gas valve closes, whether room
heating is enabled or not?
Nigel
Ken Redman
quietly) whizzing through radiators and valves while the pump is
running. When the pump stops, they accumulate in high points of the
piping and can make quite a lot of gurgling noises. If this persists
after radiator bleeding, there may be a point in your system where the
pressure drops below atmospheric while the pump is running and sucks air
in (this could include the vent pipe!).
Nigel Orr wrote:
> I think this is what is happening in my system- at switch-off time,
> there is about a minute of 'gurgles'. I don't see why it should be
> worse at switch-off than at any other time- is it because the pump and
> gas supply both switch off, but there is still some heat which has not
> been transferred to the water, so it boils over? I can't see any
> other sensible reason.
>
> So a pump overrun circuit presumably just runs the pump for a minute
> or two after the room thermostat is satisfied?
>
> Wouldn't the same problem arise when the boiler is on for water
> heating only? It reaches maximum temperature, its thermostat cuts
> off, but more heat goes into the water? Is the solution to run the
> pump for a minute every time the gas valve closes, whether room
> heating is enabled or not?
--
Ken Redman
'Semper in faecibus sumus: sole profundum variat'
To reply remove dot. from email address
Nigel Orr
<ken.r...@mround.bt.co.uk> wrote:
>piping and can make quite a lot of gurgling noises. If this persists
>after radiator bleeding, there may be a point in your system where the
>pressure drops below atmospheric while the pump is running and sucks air
>in (this could include the vent pipe!).
Is this a bad thing (presumably causes corrosion?)- the radiators have
been bled, and no noticeable amounts of air came out- should I
investigate further, or just let it go on?
Nigel
Ken Redman
of the heat exchanger and may cause it to leak, the latter will
encourage corrosion.
If you don't get any air out when you bleed the system, it probably
means that no air is getting in....
If it worries you, investigate it! ;-)
Nigel Orr wrote:
> Is this a bad thing (presumably causes corrosion?)- the radiators have
> been bled, and no noticeable amounts of air came out- should I
> investigate further, or just let it go on?
--
Dave
<nigel.orr@ncl_dot_ac.uk> wrote:
>
> So a pump overrun circuit presumably just runs the pump for a minute
> or two after the room thermostat is satisfied?
>
> Wouldn't the same problem arise when the boiler is on for water
> heating only? It reaches maximum temperature, its thermostat cuts
> off, but more heat goes into the water? Is the solution to run the
> pump for a minute every time the gas valve closes, whether room
> heating is enabled or not?
Mine is a fully pumped system with 3-way valve. If the boiler was running
(and it's set on maximum) when either thermostat told the pump to stop, it
briefly boiled before shutting down, I assumed by the slight hysteresis in
the system. It was all wired up exactly as per the Honeywell diagram
supplied with the 3 way valve. It's a cast iron boiler, so would come to no
harm, but I though this to be wasted energy. So I built an 'overrun' circuit
using a U6047B timer chip of which I had several spare (used for 'one shot'
windows and sunroof on the old Rover, but that's another story) which is
designed to drive a relay. All the bits I used I had 'in stock'. Designing
one from scratch I would do it more cheaply.
It runs the pump for 1 minute and just dumps the extra heat into either the
heating or hot water, whichever the valve is feeding.
But I thought most new systems did this anyway.
Richard Gethin
can't tell you what the problem is but I do have a few observations.
The gravity pipework up to the cylinder. I assume it's 28mm? Does the
flow pipe come out of the highest point of the boiler? I wonder what
size the tappings in the boiler are? If they have to be reduced to the
size of the pipework, is the reduction done in the horizontal plane or
in the vertical?
It seems that the noise you can hear is water vapour rather than air
because you are not getting air in the radiators. The water vapour is
condensing back to water once it gets past the pump?
I wonder if localized boiling is taking place in the boiler. Perhaps
because of a gas rate that is too high?
Is the boiler really suitable for use on a gravity system?
I wonder if water vapour is building up in the top of the boiler,
especially as it reaches its top temperature, until it cannot hold any
more so it gets sucked into the pump?
Are both the isolating valves by the pump fully open?
What is the arrangement at the boiler with the pipework? Do all four
pipes use separate tappings or is an injector tee used to aid the
gravity circulation?
Lot of wondering, eh?
In article <7ccmps$kn0$1...@news4.svr.pol.co.uk>, Maxine Evans <maxine@evan
s155.freeserve.co.uk> writes
>Can an incorrectly balanced system cause noise problems with a central
>heating pump? I am asking because I have had a problem that has been
>occuring for nearly 2 years now and this is just about the last thing left.
>We've had the boiler manufacturers and the installer out about 30 times and
>both say there is nothing wrong with the boiler or the installation.
>However, both agree that the noise is a serious problem!!
>
--
Richard Gethin
John
Maxine Evans wrote in message
>Hi John,
SNIP
>
>Pumped flow - However, it has also been tried on the
return but that didn't
>cure the problem either.
No it wouldn't
>
>>Since Potterton don't usually replace boilers simply
>>because they are noisy can you tell us WHY they
replaced
>>yours.
>
>We've had one new boiler and one replacement - 2
boilers in all. Potterton
>replaced the original boiler because the installer had
tried everything that
>they had suggested to cure the noise i.e. raising the
HW cylinder, putting
>in automatic bleed valves, cleanser & inhibitor etc.
etc. Potterton thought
>that we might have a faulty heat exchanger - iron
filings left inside?? -
>but it was apparently easier to replace the whole
boiler. Both Potterton and
>the installer agree that something is wrong and that
apart from the
>possibility of corrosion - it is extremely annoying to
listen to! There
>weren't any leaks as far as I'm aware.
What brand and grade of cleanser and inhibitor are we
talking about?
>
>>How high above the pump is the F&E tank?
>
>The F&E tank is on it's own platform in the loft - as
high as it can go, and
>the pump is on the ground floor by the boiler - the
lowest it can go.
So we are probably talking of 25 feet or more?
>These radiators are red-hot now - Can I safely assume
that any blockage has
>been cleared?
Sounds feasible did they clear themselves or did you
purge the pipes?
>
SNIP
>
>Does having TRV's mean that balancing isn't *so*
important then? Also, does
>having too many TRV's have an adverse effect on the
system? We have them on
>8 of the 9 radiators and I have wondered if this could
cause a problem. One
>more thing, is there a way to work out what speed the
pump should be on? I
>have a feeling that it should be on 2 and if so, will
the radiator balance
>be totally different than when the pump speed is on 1?
If the pump is on setting one and all your radiators are
now clear and hot lets leave that for a moment
>
SNIP
>
>It does sound as though the glug goes backwards through
the pump towards the
>boiler - as though the pump is drawing water back from
the radiators.
>
>If it gives you any clues, the only thing that is
pretty consistent about
>the noise is that it nearly always occurs just after
the boiler cuts out
>when it has reached temperature. The boiler clicks off
and then almost
>immediately we get the glugging - however, it doesn't
happen every time.
Can you be specific about what the pump is doing at that
moment - does it stop at the same time or does it carry
on running while the glugging is going on?
>
>>This can occasionally happen with a pump on
>>the flow if the head tank is not high enough above the
>>pump as well but pumped return is the most common
cause.
>
>The F&E tank is as high as it can go and the pump is on
the flow. Are there
>any other reasons for a drop in pressure?
>
>I am really sorry to ask so many questions!! This
could turn out to be
>quite a lengthy problem, so please feel free to tell me
to go away at any
>time!!
>
Can you describe more fully the exact arrangement of the
pipes around the boiler?
For example (and I'm guessing here) does the flow pipe
to the pump come off the top of the boiler and turn
downwards to the pump then carry on down further after
the pump. If this is the case is there any means of
clearing air from the pipes above the pump when the pump
stops such as a vent or another pipe going up say to the
cylinder coil and hopefully to the F&E vent pipe. If
there is a manual vent above the pump do you get
repeated quantities of air/hydrogen out of it when the
pump is stopped after a run? If it has been fitted with
an auto vent here can you try closing the nipple off for
a day or so and then opening it to see if a quantity of
air accumulates.
Could you sketch out a pipe arrangement and email it to
me (take the AS out of my address to get through)
If you can't do this please email me privately for my
address
Maxine Evans
regarding my glugging pump and associated problems.
My grandmother is in hospital at the moment and so I have not been able to
use my computer very much. I will answer everyone's messages, but it might
not be for another week or so.
Just thought I'd let you know that I haven't forgotten to reply and that I
will answer your questions as soon as possible.
Thanks for all your help,
Kind regards,
Maxine Evans :-))