I've got a sealed central heating system that slowly loses pressure
over a period of a few days. I need to keep adding water to the system
otherwise the pump seizes up and my hot water and heating go off. I've
tried Fernox leak fix but no joy. I've got wooden floors and tiles on
top of the concrete floors, so identifying where the leak might be is
almost impossible, with no evidence of damp as a guide.

How can I go about fixing the leak or who could I get in touch with to
help? Local plumbers haven't come up with any bright ideas, just a
shrug of the shoulders when they replace my pump yet again.

Thanks in advance,

Simon

almost certainly it is because your copper pipes were poor quality when
fitted and were not protected from the corrosion caused by touching the
cement in the concrete. You will have a serious if not impossible job of
fixing the leak(s) due to the whole pipe will be affected. All you can do is
repleace all the heating pipes where buried in concrete. This may be easier
and cheaper to replace all the flow and returns to the rads to a more
convenient position without being buried within the floor screed. I.E. all
within the 1st floor joists then on drops to each rad.
I cannot see how any plumber would be interested in "fixing" the leak as it
will go again tomorrow, day after or next week and you will then blame him.
Best of luck

"Mike Taylor" wrote in
message ...
almost certainly it is because your copper pipes were poor quality when
fitted and were not protected from the corrosion caused by touching the
cement in the concrete. You will have a serious if not impossible job of
fixing the leak(s) due to the whole pipe will be affected. All you can do
is
repleace all the heating pipes where buried in concrete.

....That's assuming the leak IS in the concrete!

Sparks...

In article ,
"Sparks" writes:
"Mike Taylor" wrote in
message ...
almost certainly it is because your copper pipes were poor quality when
fitted and were not protected from the corrosion caused by touching the
cement in the concrete. You will have a serious if not impossible job of
fixing the leak(s) due to the whole pipe will be affected. All you can do
is
repleace all the heating pipes where buried in concrete.

...That's assuming the leak IS in the concrete!

We've had a few threads recently where people can see all the
pipework, and still can't find the leak, so being unable to
immediately see the leak doesn't imply it's out of sight.
Look back over those for some tips.

--
Andrew Gabriel

"sryley" wrote in message
om...
I've got a sealed central heating system that slowly loses pressure
over a period of a few days. I need to keep adding water to the system
otherwise the pump seizes up and my hot water and heating go off. I've
tried Fernox leak fix but no joy. I've got wooden floors and tiles on
top of the concrete floors, so identifying where the leak might be is
almost impossible, with no evidence of damp as a guide.

How can I go about fixing the leak or who could I get in touch with to
help? Local plumbers haven't come up with any bright ideas, just a
shrug of the shoulders when they replace my pump yet again.

Thanks in advance,

Simon

Check the leak is not in fact water being lost out of the overpressure valve
( should vent outside ) when the system fires up. To test, I'd suggest
repressurising the system, and watching the vent outlet when the CH comes
on. The underlying problem might then be your expansion vessel, which may
have lost its air charge. Just a possibility,

Andy.

"andrewpreece" wrote in message ...
"sryley" wrote in message
om...
I've got a sealed central heating system that slowly loses pressure
over a period of a few days. I need to keep adding water to the system
otherwise the pump seizes up and my hot water and heating go off. I've
tried Fernox leak fix but no joy. I've got wooden floors and tiles on
top of the concrete floors, so identifying where the leak might be is
almost impossible, with no evidence of damp as a guide.

How can I go about fixing the leak or who could I get in touch with to
help? Local plumbers haven't come up with any bright ideas, just a
shrug of the shoulders when they replace my pump yet again.

Thanks in advance,

Simon

Check the leak is not in fact water being lost out of the overpressure valve
( should vent outside ) when the system fires up. To test, I'd suggest
repressurising the system, and watching the vent outlet when the CH comes
on. The underlying problem might then be your expansion vessel, which may
have lost its air charge. Just a possibility,

Andy.

Thanks for all the replies. Having found and read the plumbing FAQ it
does sound like the problem is with the release valve rather than the
pipes. I have used it in the past, and when I tried it again recently
it did change the rate at which the pressure was dropping. As
sometimes its over as little as 1 day but other times it takes a week
or more to drop to zero then that would suggest it wasn't the pipes?
(he says hopefully)

I saw the pipes go in and there was plenty of insulation around them
before concrete was poured. I was a bit worried as a big tree in the
back was chopped down which affected the foundations a bit -
doorframes started sticking the following year. I thought that might
have affected the pipes, or that I caused a leak when I turned the
pressure up past 3 bars once, at the time not knowing how much to turn
it up to when it had dropped. Could that have caused a leak or should
pipes be able to handle that ok? Does the variable rate of pressure
dropping suggest the release valve?

Many thanks,

Simon

"andrewpreece" wrote in message ...
"sryley" wrote in message
om...
I've got a sealed central heating system that slowly loses pressure
over a period of a few days. I need to keep adding water to the system
otherwise the pump seizes up and my hot water and heating go off. I've
tried Fernox leak fix but no joy. I've got wooden floors and tiles on
top of the concrete floors, so identifying where the leak might be is
almost impossible, with no evidence of damp as a guide.

How can I go about fixing the leak or who could I get in touch with to
help? Local plumbers haven't come up with any bright ideas, just a
shrug of the shoulders when they replace my pump yet again.

Thanks in advance,

Simon

Check the leak is not in fact water being lost out of the overpressure valve
( should vent outside ) when the system fires up. To test, I'd suggest
repressurising the system, and watching the vent outlet when the CH comes
on. The underlying problem might then be your expansion vessel, which may
have lost its air charge. Just a possibility,

Andy.

Thanks for all the replies. Having found and read the plumbing FAQ it
does sound like the problem is with the release valve rather than the
pipes. I have used it in the past, and when I tried it again recently
it did change the rate at which the pressure was dropping. As
sometimes its over as little as 1 day but other times it takes a week
or more to drop to zero then that would suggest it wasn't the pipes?
(he says hopefully)

I saw the pipes go in and there was plenty of insulation around them
before concrete was poured. I was a bit worried as a big tree in the
back was chopped down which affected the foundations a bit -
doorframes started sticking the following year. I thought that might
have affected the pipes, or that I caused a leak when I turned the
pressure up past 3 bars once, at the time not knowing how much to turn
it up to when it had dropped. Could that have caused a leak or should
pipes be able to handle that ok? Does the variable rate of pressure
dropping suggest the release valve?

Many thanks,

Simon

"sryley" wrote in message
om...
"andrewpreece" wrote in message
...
"sryley" wrote in message
om...
I've got a sealed central heating system that slowly loses pressure
over a period of a few days. I need to keep adding water to the system
otherwise the pump seizes up and my hot water and heating go off. I've
tried Fernox leak fix but no joy. I've got wooden floors and tiles on
top of the concrete floors, so identifying where the leak might be is
almost impossible, with no evidence of damp as a guide.

How can I go about fixing the leak or who could I get in touch with to
help? Local plumbers haven't come up with any bright ideas, just a
shrug of the shoulders when they replace my pump yet again.

Thanks in advance,

Simon

Check the leak is not in fact water being lost out of the overpressure
valve
( should vent outside ) when the system fires up. To test, I'd suggest
repressurising the system, and watching the vent outlet when the CH
comes
on. The underlying problem might then be your expansion vessel, which
may
have lost its air charge. Just a possibility,

Andy.

Thanks for all the replies. Having found and read the plumbing FAQ it
does sound like the problem is with the release valve rather than the
pipes. I have used it in the past, and when I tried it again recently
it did change the rate at which the pressure was dropping. As
sometimes its over as little as 1 day but other times it takes a week
or more to drop to zero then that would suggest it wasn't the pipes?
(he says hopefully)

I saw the pipes go in and there was plenty of insulation around them
before concrete was poured. I was a bit worried as a big tree in the
back was chopped down which affected the foundations a bit -
doorframes started sticking the following year. I thought that might
have affected the pipes, or that I caused a leak when I turned the
pressure up past 3 bars once, at the time not knowing how much to turn
it up to when it had dropped. Could that have caused a leak or should
pipes be able to handle that ok? Does the variable rate of pressure
dropping suggest the release valve?

Many thanks,

Simon

I think your CH pipes should handle 3 bar with ease, unless faulty. My over-
pressure valve blows at 3 bar. If you pressurise your system and note the
pressure,
then don't use the CH at all for a while ( difficult perhaps in winter ) the
pressure
should hold unless there is a leaky pipe ( or radiator ). If the system is
venting
via the blowoff valve due to overpressure, this should only occur when the
system's
in use and the water in the CH loop gets hot, expands, and finds it has no
expansion
vessel to expand into, so causing an overpressure and a blow off. If you
can't be
done with this method, can you stick a balloon or receptacle over the
blowoff
vent ( whereever it emerges from your wall, presumably very close to the
boiler )
and check and see after a few days, or a pressure loss, whether it has
vented any water.

Andy.

I would look at total replcement of the suspected pipes. It might be work bodging in a bit of hose pipe (run over the floor) to test your theory - but this might just turn into its own leak ridden
nightmare.

If you are *REALLY" lucky you might be able to get a new small pipe inside the old pipe, but if you have sharp bends you are stuffed. Even if you do this, you will reduce the flow, possibly so much the
heating does not work.

Rick

On 6 Jan 2004 08:42:09 -0800, (sryley) wrote:
I've got a sealed central heating system that slowly loses pressure
over a period of a few days. I need to keep adding water to the system
otherwise the pump seizes up and my hot water and heating go off. I've
tried Fernox leak fix but no joy. I've got wooden floors and tiles on
top of the concrete floors, so identifying where the leak might be is
almost impossible, with no evidence of damp as a guide.

How can I go about fixing the leak or who could I get in touch with to
help? Local plumbers haven't come up with any bright ideas, just a
shrug of the shoulders when they replace my pump yet again.

Thanks in advance,

Simon

"Rick Dipper" wrote in message
...
I would look at total replcement of the suspected pipes. It might be work
bodging in a bit of hose pipe (run over the floor) to test your theory - but
this might just turn into its own leak ridden
nightmare.

If you are *REALLY" lucky you might be able to get a new small pipe inside
the old pipe, but if you have sharp bends you are stuffed. Even if you do
this, you will reduce the flow, possibly so much the
heating does not work.

Rick

On 6 Jan 2004 08:42:09 -0800, (sryley) wrote:
I've got a sealed central heating system that slowly loses pressure
over a period of a few days. I need to keep adding water to the system
otherwise the pump seizes up and my hot water and heating go off. I've
tried Fernox leak fix but no joy. I've got wooden floors and tiles on
top of the concrete floors, so identifying where the leak might be is
almost impossible, with no evidence of damp as a guide.

How can I go about fixing the leak or who could I get in touch with to
help? Local plumbers haven't come up with any bright ideas, just a
shrug of the shoulders when they replace my pump yet again.

Thanks in advance,

Simon


I've come into this thread quite late, and haven't read any of it other than
the above. See "How does air get into a pressurised system" below.
I've got exactly the same problem. So far I've identified most of the leaks
(and fixed them).
Some tips:
Check all pipes for green staining - if it is there clean it off and see if
it comes back.
Check the ceilings for barely visible staining
Check the door frames for rot where they go into the floor.
Keep all your doors shut and go away for the weekend (remembering to top the
system up first). The smelly rooms have leaks.
Slide a piece of paper under the wooden floor and leave it there for a
couiple of hours. If it feels damp when it comes out, then you've a leak
somewhere in the room.
Check any self bleeding valves
Finally, set aside a week in the summer to drop down new pipes and box them
in.......

Do you live in Surrey?
Jon (whose CH pipes have caused more hassle than his Saniflo clone......)

On 6 Jan 2004 08:42:09 -0800, (sryley) wrote:
I've got a sealed central heating system that slowly loses pressure
over a period of a few days. I need to keep adding water to the system
otherwise the pump seizes up and my hot water and heating go off. I've
tried Fernox leak fix but no joy. I've got wooden floors and tiles on
top of the concrete floors, so identifying where the leak might be is
almost impossible, with no evidence of damp as a guide.

How can I go about fixing the leak or who could I get in touch with to
help? Local plumbers haven't come up with any bright ideas, just a
shrug of the shoulders when they replace my pump yet again.

Thanks in advance,

Simon


How come you get to a point where the pump seizes up ??
Is there a pressure guage on your system ??
If not it is quite easy to have one fitted, this will tell you when to top
up the system and will give you a bit more warning as to the pressure level
in your system.
see link
http://www.plumbworld.co.uk/acb/show...=403&CATID=109

If you order, ask the salesman, for the fitting that goes with it, depends
on where you are going to fit it. 15mm or 22mm
I have fitted a few of these on systems without guages and they are great.

Finding leaks are a nightmare, they could be anywhere,
I suppose all you have to do is trace all pipework, mark everything that you
have inspected so as not to go over it twice, look at where the pipes go
into walls , they could be rubbing the wall, sprung a small leak, and
empties into a cavity.

hope it helps
mike

I've come into this thread quite late, and haven't read any of it other
than
the above. See "How does air get into a pressurised system" below.
I've got exactly the same problem. So far I've identified most of the
leaks
(and fixed them).
Some tips:
Check all pipes for green staining - if it is there clean it off and see
if
it comes back.
Check the ceilings for barely visible staining
Check the door frames for rot where they go into the floor.
Keep all your doors shut and go away for the weekend (remembering to top
the
system up first). The smelly rooms have leaks.
Slide a piece of paper under the wooden floor and leave it there for a
couiple of hours. If it feels damp when it comes out, then you've a leak
somewhere in the room.
Check any self bleeding valves
Finally, set aside a week in the summer to drop down new pipes and box
them
in.......

Do you live in Surrey?
Jon (whose CH pipes have caused more hassle than his Saniflo clone......)

I agree with all that, the green staining is usually residue from power
flux, left from the installation and soldering of the pipes, this should be
cleaned off before it corrodes the pipes. It takes years to corrode, so its
probably not going to be your main problem

mike