Hello uk.d-i-y world.

Yesterday, I thought I'd put the heating on... it being June and all.

There was a bit of gurgling from a radiator that usually gurgles, so I
bled it and put a bit more water into the system - by turning a thing
that is a bit like a washing machine tap. System came on and worked for
a bit then it stopped working. I was puzzled but left it to this morning
to have a closer look.

The boiler is a Worcester Bosch Greenstar CDi that was fitted last
November. The plumbing (radiators etc.) are of an older (~90s) vintage.

The hot water is working fine.

This morning, before switching on, the system pressure gauge showed 0,
and the display 72 (I guess degrees). I'm not sure what these numbers
would normally be before switching on.

After I switched it on, the temperature quickly rose past 99 and then
u1.. u9 (which I guess is not right). The radiators didn't come on. I
bled a few and a little bit of air and distant gurgling occurred, but no
actual water.

I'm about to call our service guy, but just to get an idea... Is this
likely to be the boiler? or, more horribly, a pipework issue?

(The house is a bungalow, and I'm a bit worried that the pipework could
be dumping water without us knowing).

Thanks for any ideas.

Bob.

"WeeBob" wrote in message
...
Hello uk.d-i-y world.

Yesterday, I thought I'd put the heating on... it being June and all.

There was a bit of gurgling from a radiator that usually gurgles, so I
bled it and put a bit more water into the system - by turning a thing that
is a bit like a washing machine tap. System came on and worked for a bit
then it stopped working. I was puzzled but left it to this morning to have
a closer look.

The boiler is a Worcester Bosch Greenstar CDi that was fitted last
November. The plumbing (radiators etc.) are of an older (~90s) vintage.

The hot water is working fine.

This morning, before switching on, the system pressure gauge showed 0, and
the display 72 (I guess degrees). I'm not sure what these numbers would
normally be before switching on.

After I switched it on, the temperature quickly rose past 99 and then u1..
u9 (which I guess is not right). The radiators didn't come on. I bled a
few and a little bit of air and distant gurgling occurred, but no actual
water.

I'm about to call our service guy, but just to get an idea... Is this
likely to be the boiler? or, more horribly, a pipework issue?

(The house is a bungalow, and I'm a bit worried that the pipework could be
dumping water without us knowing).

Thanks for any ideas.

Bob.

I'm guess that you have a pressurized system. So if you did have a leak,
there'll be no water left to fill the radiators when you try to bleed them.

Depending on how much you believe you know, you can either wait for the
engineer or try repressurising the system gently whilst you or a
spouse/friend check around the bungalow listening for leaking water. If you
can't find any, bleed, repressure, bleed until the system seems full and try
the heating - you'll probably have to bleed/refill again as there'll be air
moved around once the heating starts up. Then watch the pressure again and
see if it drops indicating a leak.

If the pipes are buried then feel for wet bits of carpet etc. and don't
forget any unused rooms, garage (if there are pipes in there) etc.

Good luck!
Paul DS.

On Mon, 11 Jun 2012 08:59:02 +0100, WeeBob wrote:

Hello uk.d-i-y world.

Yesterday, I thought I'd put the heating on... it being June and all.

There was a bit of gurgling from a radiator that usually gurgles, so I
bled it and put a bit more water into the system - by turning a thing
that is a bit like a washing machine tap. System came on and worked for
a bit then it stopped working. I was puzzled but left it to this morning
to have a closer look.

The boiler is a Worcester Bosch Greenstar CDi that was fitted last
November. The plumbing (radiators etc.) are of an older (~90s) vintage.

The hot water is working fine.

This morning, before switching on, the system pressure gauge showed 0,
and the display 72 (I guess degrees). I'm not sure what these numbers
would normally be before switching on.

After I switched it on, the temperature quickly rose past 99 and then
u1.. u9 (which I guess is not right). The radiators didn't come on. I
bled a few and a little bit of air and distant gurgling occurred, but no
actual water.

I'm about to call our service guy, but just to get an idea... Is this
likely to be the boiler? or, more horribly, a pipework issue?

(The house is a bungalow, and I'm a bit worried that the pipework could
be dumping water without us knowing).

Thanks for any ideas.

Bob.

Is your expansion vessel still pressurised ? I had a problem a few months
ago with our CH - kept on losing pressure by blowing water out of the
safety valve. Turned out the expansion vessel had lost some air. After
some acrobatics on a chair, I managed to connect a bicycle pump to it,
and repressurise. Been fine since.

Can't speak for your model, but expansion vessel on mine was right at the
back of the boiler and a pig to reach . If it needs replacing, most
engineers simply fit one elsewhere !

On Mon, 11 Jun 2012 08:59:02 +0100, WeeBob wrote:

Yesterday, I thought I'd put the heating on... it being June and all.

There was a bit of gurgling from a radiator that usually gurgles, so I
bled it and put a bit more water into the system - by turning a thing
that is a bit like a washing machine tap.

You shouldn't have gurgling radiators or need to regularly bleed
"air" from the system. As you say this is a recent install did the
person who replaced the boiler add inhibitor to the system when they
refilled it?
"Air" is in quotes as it maybe hydrogen, the result of corrosion in
the system due to lack of inhibitor.

This morning, before switching on, the system pressure gauge showed 0,

So it's lost pressure, this does half indicate a leak but it might
not be in the pipe work. A common culprit is a lump of crud in the
pressure relief valve or a failed expansion vessel (pressure shoots
up when the system fires, (opening relief valve allowing crud into
it...), then when the system cools the pressure drops right back.

--
Cheers
Dave.

On 11/06/2012 09:21, Paul D Smith wrote:
"WeeBob" wrote in message
...
Hello uk.d-i-y world.

Yesterday, I thought I'd put the heating on... it being June and all.

There was a bit of gurgling from a radiator that usually gurgles, so I
bled it and put a bit more water into the system - by turning a thing
that is a bit like a washing machine tap. System came on and worked
for a bit then it stopped working. I was puzzled but left it to this
morning to have a closer look.

The boiler is a Worcester Bosch Greenstar CDi that was fitted last
November. The plumbing (radiators etc.) are of an older (~90s) vintage.

The hot water is working fine.

This morning, before switching on, the system pressure gauge showed 0,
and the display 72 (I guess degrees). I'm not sure what these numbers
would normally be before switching on.

After I switched it on, the temperature quickly rose past 99 and then
u1.. u9 (which I guess is not right). The radiators didn't come on. I
bled a few and a little bit of air and distant gurgling occurred, but
no actual water.

I'm about to call our service guy, but just to get an idea... Is this
likely to be the boiler? or, more horribly, a pipework issue?

(The house is a bungalow, and I'm a bit worried that the pipework
could be dumping water without us knowing).

Thanks for any ideas.

Bob.

I'm guess that you have a pressurized system. So if you did have a leak,
there'll be no water left to fill the radiators when you try to bleed them.

Depending on how much you believe you know, you can either wait for the
engineer or try repressurising the system gently whilst you or a
spouse/friend check around the bungalow listening for leaking water. If
you can't find any, bleed, repressure, bleed until the system seems full
and try the heating - you'll probably have to bleed/refill again as
there'll be air moved around once the heating starts up. Then watch the
pressure again and see if it drops indicating a leak.

If the pipes are buried then feel for wet bits of carpet etc. and don't
forget any unused rooms, garage (if there are pipes in there) etc.


Never underestimate the amount of water a ceiling can hold before
breaking through! I reckon mine had been leaking for some months -
pressure to zero after a week or two - before I finally got round to
having a systematic look.

Fixed a pipe under the FF floorboards and replaced all rad valves while
it was drained. Figured it was a false effort/economy not to do the
valves, especially as a couple showed signs of weeping.

Rob

On 11/06/2012 08:59, WeeBob wrote:
Hello uk.d-i-y world.

Yesterday, I thought I'd put the heating on... it being June and all.

There was a bit of gurgling from a radiator that usually gurgles, so I
bled it and put a bit more water into the system - by turning a thing
that is a bit like a washing machine tap. System came on and worked for
a bit then it stopped working. I was puzzled but left it to this morning
to have a closer look.

The boiler is a Worcester Bosch Greenstar CDi that was fitted last
November. The plumbing (radiators etc.) are of an older (~90s) vintage.

The hot water is working fine.

This morning, before switching on, the system pressure gauge showed 0,
and the display 72 (I guess degrees). I'm not sure what these numbers
would normally be before switching on.

After I switched it on, the temperature quickly rose past 99 and then
u1.. u9 (which I guess is not right). The radiators didn't come on. I
bled a few and a little bit of air and distant gurgling occurred, but no
actual water.

I'm about to call our service guy, but just to get an idea... Is this
likely to be the boiler? or, more horribly, a pipework issue?

(The house is a bungalow, and I'm a bit worried that the pipework could
be dumping water without us knowing).

Thanks for any ideas.

Bob.





Hm... After checking stuff further, the hot water is not working. I
guess there was just enough left in the tank to have a shower this morning.

On 11/06/2012 10:24, WeeBob wrote:
On 11/06/2012 08:59, WeeBob wrote:
Hello uk.d-i-y world.

Yesterday, I thought I'd put the heating on... it being June and all.

There was a bit of gurgling from a radiator that usually gurgles, so I
bled it and put a bit more water into the system - by turning a thing
that is a bit like a washing machine tap. System came on and worked for
a bit then it stopped working. I was puzzled but left it to this morning
to have a closer look.

The boiler is a Worcester Bosch Greenstar CDi that was fitted last
November. The plumbing (radiators etc.) are of an older (~90s) vintage.

The hot water is working fine.

This morning, before switching on, the system pressure gauge showed 0,
and the display 72 (I guess degrees). I'm not sure what these numbers
would normally be before switching on.

After I switched it on, the temperature quickly rose past 99 and then
u1.. u9 (which I guess is not right). The radiators didn't come on. I
bled a few and a little bit of air and distant gurgling occurred, but no
actual water.

I'm about to call our service guy, but just to get an idea... Is this
likely to be the boiler? or, more horribly, a pipework issue?

(The house is a bungalow, and I'm a bit worried that the pipework could
be dumping water without us knowing).

Thanks for any ideas.

Bob.





Hm... After checking stuff further, the hot water is not working. I
guess there was just enough left in the tank to have a shower this morning.



The pressure should read about 1.0 when the system is cold, so if the
pressure dropped to 0 then the boiler would (should!) refuse to fire,
although it sounds like it may have fired anyway and then tripped an
overheat sensor as you said "After I switched it on, the temperature
quickly rose past 99 and then u1.. u9" so you may need to reset
something once you have taken the pressure back up to 1.0.

I suggest you do the following...

1. Turn off the hot water, so the boiler isn't trying to heat the hot
water cylinder.
2. Turn down your room stat so it is not trying to heat the radiators

3. make sure your bleed valves are all closed on the radiators

3. try letting more water into the system with the valve that looks a
bit like a washing machine tap, and watch the display on the front of
the boiler, you should see it rise from 0 - Stop when you get to 0.5

4. Hunt around the house to see if anything is leaking, including
outside at the back of the boiler, where you should find a metal
(copper) pipe that should either end part way down the wall, or go to
the ground, but not go to a drain

5 If there any any leaks, top it up until it is at 1.0 and check again.

6. If you cant see any leaks, leave it like this for 15 minutes or so,
and see if the pressure drops.

7 If not, go round and bleed your radiators, if there is a lot of air in
them, you will need to go back and fill the system again every so often,
as bleeding the air will result in a loss of pressure.

8. Once they are all bled, and you have topped it back up to 1.0 fire up
the heating and see how it goes.

Let us know if you run into a problem!
--
Toby...
Remove pants to reply

On 11/06/2012 11:18, Toby wrote:
On 11/06/2012 10:24, WeeBob wrote:
On 11/06/2012 08:59, WeeBob wrote:
Hello uk.d-i-y world.

Yesterday, I thought I'd put the heating on... it being June and all.

There was a bit of gurgling from a radiator that usually gurgles, so I
bled it and put a bit more water into the system - by turning a thing
that is a bit like a washing machine tap. System came on and worked for
a bit then it stopped working. I was puzzled but left it to this morning
to have a closer look.

The boiler is a Worcester Bosch Greenstar CDi that was fitted last
November. The plumbing (radiators etc.) are of an older (~90s) vintage.

The hot water is working fine.

This morning, before switching on, the system pressure gauge showed 0,
and the display 72 (I guess degrees). I'm not sure what these numbers
would normally be before switching on.

After I switched it on, the temperature quickly rose past 99 and then
u1.. u9 (which I guess is not right). The radiators didn't come on. I
bled a few and a little bit of air and distant gurgling occurred, but no
actual water.

I'm about to call our service guy, but just to get an idea... Is this
likely to be the boiler? or, more horribly, a pipework issue?

(The house is a bungalow, and I'm a bit worried that the pipework could
be dumping water without us knowing).

Thanks for any ideas.

Bob.





Hm... After checking stuff further, the hot water is not working. I
guess there was just enough left in the tank to have a shower this
morning.



The pressure should read about 1.0 when the system is cold, so if the
pressure dropped to 0 then the boiler would (should!) refuse to fire,
although it sounds like it may have fired anyway and then tripped an
overheat sensor as you said "After I switched it on, the temperature
quickly rose past 99 and then u1.. u9" so you may need to reset
something once you have taken the pressure back up to 1.0.

I suggest you do the following...

1. Turn off the hot water, so the boiler isn't trying to heat the hot
water cylinder.
2. Turn down your room stat so it is not trying to heat the radiators

3. make sure your bleed valves are all closed on the radiators

3. try letting more water into the system with the valve that looks a
bit like a washing machine tap, and watch the display on the front of
the boiler, you should see it rise from 0 - Stop when you get to 0.5

4. Hunt around the house to see if anything is leaking, including
outside at the back of the boiler, where you should find a metal
(copper) pipe that should either end part way down the wall, or go to
the ground, but not go to a drain

5 If there any any leaks, top it up until it is at 1.0 and check again.

6. If you cant see any leaks, leave it like this for 15 minutes or so,
and see if the pressure drops.

7 If not, go round and bleed your radiators, if there is a lot of air in
them, you will need to go back and fill the system again every so often,
as bleeding the air will result in a loss of pressure.

8. Once they are all bled, and you have topped it back up to 1.0 fire up
the heating and see how it goes.

Let us know if you run into a problem!


All good stuff, but if the expansion vessel is shot - or or has just
lost its pressure - no 'leaks' will be found until the system gets hot
again, whereupon the pressure relief valve will open and will discharge
water outside.

So, to the OP . . . When you get to the end of the above list, if you
haven't found any leaks (as seems likely), keep a careful eye on the
pressure gauge as the system heats up - and look for water flowing
outside, wherever the outlet from the PRV discharges - particularly if
the pressure has got above 3 bar. If this *is* happening, report back -
and we'll tell you in a bit more detail how to fix your expansion
vessel. Oh, and if the boiler still refuses to fire when you've restored
the pressure to 1 bar, look for an over=temperature trip which needs to
be manually reset.
--
Cheers,
Roger
____________
Please reply to Newsgroup. Whilst email address is valid, it is seldom
checked.

On 11/06/2012 08:59, WeeBob wrote:
Hello uk.d-i-y world.

Yesterday, I thought I'd put the heating on... it being June and all.

There was a bit of gurgling from a radiator that usually gurgles, so I
bled it and put a bit more water into the system - by turning a thing
that is a bit like a washing machine tap. System came on and worked for
a bit then it stopped working. I was puzzled but left it to this morning
to have a closer look.

The boiler is a Worcester Bosch Greenstar CDi that was fitted last
November. The plumbing (radiators etc.) are of an older (~90s) vintage.

The hot water is working fine.

This morning, before switching on, the system pressure gauge showed 0,

Its not right (typically it would show around 1 bar on a cold system and
more on a hot one), but may not be a leak...

It could also be a classic symptom of inadequate expansion space. See
the sealed system FAQ:

http://www.makewrite.demon.co.uk/SealedCH.html



--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 11/06/2012 11:18, Toby wrote:
On 11/06/2012 10:24, WeeBob wrote:
On 11/06/2012 08:59, WeeBob wrote:
Hello uk.d-i-y world.

Yesterday, I thought I'd put the heating on... it being June and all.

There was a bit of gurgling from a radiator that usually gurgles, so I
bled it and put a bit more water into the system - by turning a thing
that is a bit like a washing machine tap. System came on and worked for
a bit then it stopped working. I was puzzled but left it to this morning
to have a closer look.

The boiler is a Worcester Bosch Greenstar CDi that was fitted last
November. The plumbing (radiators etc.) are of an older (~90s) vintage.

The hot water is working fine.

This morning, before switching on, the system pressure gauge showed 0,
and the display 72 (I guess degrees). I'm not sure what these numbers
would normally be before switching on.

After I switched it on, the temperature quickly rose past 99 and then
u1.. u9 (which I guess is not right). The radiators didn't come on. I
bled a few and a little bit of air and distant gurgling occurred, but no
actual water.

I'm about to call our service guy, but just to get an idea... Is this
likely to be the boiler? or, more horribly, a pipework issue?

(The house is a bungalow, and I'm a bit worried that the pipework could
be dumping water without us knowing).

Thanks for any ideas.

Bob.





Hm... After checking stuff further, the hot water is not working. I
guess there was just enough left in the tank to have a shower this
morning.



The pressure should read about 1.0 when the system is cold, so if the
pressure dropped to 0 then the boiler would (should!) refuse to fire,
although it sounds like it may have fired anyway and then tripped an
overheat sensor as you said "After I switched it on, the temperature
quickly rose past 99 and then u1.. u9" so you may need to reset
something once you have taken the pressure back up to 1.0.

I suggest you do the following...

1. Turn off the hot water, so the boiler isn't trying to heat the hot
water cylinder.
2. Turn down your room stat so it is not trying to heat the radiators

3. make sure your bleed valves are all closed on the radiators

3. try letting more water into the system with the valve that looks a
bit like a washing machine tap, and watch the display on the front of
the boiler, you should see it rise from 0 - Stop when you get to 0.5

4. Hunt around the house to see if anything is leaking, including
outside at the back of the boiler, where you should find a metal
(copper) pipe that should either end part way down the wall, or go to
the ground, but not go to a drain

5 If there any any leaks, top it up until it is at 1.0 and check again.

6. If you cant see any leaks, leave it like this for 15 minutes or so,
and see if the pressure drops.

7 If not, go round and bleed your radiators, if there is a lot of air in
them, you will need to go back and fill the system again every so often,
as bleeding the air will result in a loss of pressure.

8. Once they are all bled, and you have topped it back up to 1.0 fire up
the heating and see how it goes.

Let us know if you run into a problem!


Thanks for that really detailed list.

Briefly, switched it all off. Filled it all up. Waited for 10mins,
pressure back at 0.

On 11/06/2012 08:59, WeeBob wrote:
Hello uk.d-i-y world.

Yesterday, I thought I'd put the heating on... it being June and all.

There was a bit of gurgling from a radiator that usually gurgles, so I
bled it and put a bit more water into the system - by turning a thing
that is a bit like a washing machine tap. System came on and worked for
a bit then it stopped working. I was puzzled but left it to this morning
to have a closer look.

The boiler is a Worcester Bosch Greenstar CDi that was fitted last
November. The plumbing (radiators etc.) are of an older (~90s) vintage.

The hot water is working fine.

This morning, before switching on, the system pressure gauge showed 0,
and the display 72 (I guess degrees). I'm not sure what these numbers
would normally be before switching on.

After I switched it on, the temperature quickly rose past 99 and then
u1.. u9 (which I guess is not right). The radiators didn't come on. I
bled a few and a little bit of air and distant gurgling occurred, but no
actual water.

I'm about to call our service guy, but just to get an idea... Is this
likely to be the boiler? or, more horribly, a pipework issue?

(The house is a bungalow, and I'm a bit worried that the pipework could
be dumping water without us knowing).

Thanks for any ideas.

Bob.


To reiterate what I just posted to Toby, I switched it all off. Filled
it up, and after 10minutes the pressure was back at 0. Tried it a couple
of times with the same result.

I have to conclude now that I've got a leak.

Diagnosing where about is going to be "interesting" and probably
expensive. There is nothing visible above the floor surface, so I guess
it's underneath someplace.

Ah well.

Sincere thanks to everyone for the very useful posts. What a great
newsgroup!

On Mon, 11 Jun 2012 19:14:48 +0100, WeeBob wrote:

Briefly, switched it all off. Filled it all up. Waited for 10mins,
pressure back at 0.

You have a leak. ouch

Have you checked that the outlet from the pressure relief valve is
still dry?

--
Cheers
Dave.

On 11/06/2012 19:22, WeeBob wrote:

I have to conclude now that I've got a leak.

Diagnosing where about is going to be "interesting" and probably
expensive. There is nothing visible above the floor surface, so I
guess it's underneath someplace.


To rule out the boiler, close the flow and return isolators on the
boiler and pressurise to around 1.5 bar, if it drops, the leak lies
within the boiler. If it is a condensing boiler the water can also be
lost through the condensate pipe.

--
David

On 11/06/2012 19:14, WeeBob wrote:
On 11/06/2012 11:18, Toby wrote:
On 11/06/2012 10:24, WeeBob wrote:
On 11/06/2012 08:59, WeeBob wrote:
Hello uk.d-i-y world.

Yesterday, I thought I'd put the heating on... it being June and all.

There was a bit of gurgling from a radiator that usually gurgles, so I
bled it and put a bit more water into the system - by turning a thing
that is a bit like a washing machine tap. System came on and worked for
a bit then it stopped working. I was puzzled but left it to this
morning
to have a closer look.

The boiler is a Worcester Bosch Greenstar CDi that was fitted last
November. The plumbing (radiators etc.) are of an older (~90s) vintage.

The hot water is working fine.

This morning, before switching on, the system pressure gauge showed 0,
and the display 72 (I guess degrees). I'm not sure what these numbers
would normally be before switching on.

After I switched it on, the temperature quickly rose past 99 and then
u1.. u9 (which I guess is not right). The radiators didn't come on. I
bled a few and a little bit of air and distant gurgling occurred,
but no
actual water.

I'm about to call our service guy, but just to get an idea... Is this
likely to be the boiler? or, more horribly, a pipework issue?

(The house is a bungalow, and I'm a bit worried that the pipework could
be dumping water without us knowing).

Thanks for any ideas.

Bob.





Hm... After checking stuff further, the hot water is not working. I
guess there was just enough left in the tank to have a shower this
morning.



The pressure should read about 1.0 when the system is cold, so if the
pressure dropped to 0 then the boiler would (should!) refuse to fire,
although it sounds like it may have fired anyway and then tripped an
overheat sensor as you said "After I switched it on, the temperature
quickly rose past 99 and then u1.. u9" so you may need to reset
something once you have taken the pressure back up to 1.0.

I suggest you do the following...

1. Turn off the hot water, so the boiler isn't trying to heat the hot
water cylinder.
2. Turn down your room stat so it is not trying to heat the radiators

3. make sure your bleed valves are all closed on the radiators

3. try letting more water into the system with the valve that looks a
bit like a washing machine tap, and watch the display on the front of
the boiler, you should see it rise from 0 - Stop when you get to 0.5

4. Hunt around the house to see if anything is leaking, including
outside at the back of the boiler, where you should find a metal
(copper) pipe that should either end part way down the wall, or go to
the ground, but not go to a drain

5 If there any any leaks, top it up until it is at 1.0 and check again.

6. If you cant see any leaks, leave it like this for 15 minutes or so,
and see if the pressure drops.

7 If not, go round and bleed your radiators, if there is a lot of air in
them, you will need to go back and fill the system again every so often,
as bleeding the air will result in a loss of pressure.

8. Once they are all bled, and you have topped it back up to 1.0 fire up
the heating and see how it goes.

Let us know if you run into a problem!


Thanks for that really detailed list.

Briefly, switched it all off. Filled it all up. Waited for 10mins,
pressure back at 0.



As Dave said, I would check the "PRV" outlet, normally a copper pipe
leading outside, should be run down to the ground or just turned into
the wall. If water is coming out of this then it could be the PRV
(Pressure relief valve) that has failed, or maybe it has some crud in it
that is making it pass water (I have had this before, and manually
exercising it sorted it out), also check the condensate pipe, this
should come out the boiler (usually a plastic pipe, sometimes ribbed
flexible, like a washing machine's drain pipe) and lead to a drain
somewhere, so you will need to find the end of that and watch it to see
if it is dripping, it shouldn't drip at all when the boiler is off.

On the central heating pipes (should be 22mm) you usually have some
isolation valves you can turn off, if you turn these off and then
pressurise the boiler again, that will tell you if the water is escaping
out the boiler, or somewhere else (so if the pressure still drops, then
the problem is in the boiler, or they are passing water when off)

Do you have a copper hot water cylinder and then hot taps supped at low
pressure (that you could easily stop with your thumb)? If so, you may
have a leaking coil in the hot water cylinder which would mean water
from the boiler's circuit you pressurised is getting lost in the lower
pressure cylinder, so you wont see that anywhere - to test that you need
to check the level in your cold water tank in the loft, then pressurise
the boiler (probably a few times, depending how much water it takes to
get to 1.0 bar), and see if the level rises in the tank (obviously don't
run any taps during this test), if so, that is the problem.


--
Toby...
Remove pants to reply

On 11/06/2012 19:14, WeeBob wrote:



Thanks for that really detailed list.

Briefly, switched it all off. Filled it all up. Waited for 10mins,
pressure back at 0.


How much water did you have to put in to get from zero to 1 bar? I would
expect it to take several litres. If it only takes a small amount, it
indicates there's very little expansion capacity - pointing to a problem
with the expansion vessel. In that case, only a small amount has to
disappear somewhere else for the pressure to fail again.

Similarly, if it takes several litres, that several litres has to be
going somewhere when the pressure drops. Is it a combi boiler, or do you
have a stored hot water cylinder?
--
Cheers,
Roger
____________
Please reply to Newsgroup. Whilst email address is valid, it is seldom
checked.

On 11/06/2012 19:40, gremlin_95 wrote:
On 11/06/2012 19:22, WeeBob wrote:

I have to conclude now that I've got a leak.

Diagnosing where about is going to be "interesting" and probably
expensive. There is nothing visible above the floor surface, so I
guess it's underneath someplace.


To rule out the boiler, close the flow and return isolators on the
boiler and pressurise to around 1.5 bar, if it drops, the leak lies
within the boiler. If it is a condensing boiler the water can also be
lost through the condensate pipe.

Yup, a good test. Another check is to tie a plastic bag over the PRV
pipe with a rubber band, and see if it collects any water (it should not
normally)


--
Cheers,

John.

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