Leaking central heating system ?

C_Mababejive

It sounds more and more like a faulty pressure vessel..

50Twuncle

UPDATE ...
We had the plumbers who installed the boiler, out yesterday
They could find nothing wrong with the boiler !!
I made a mistake - thinking that the dripping was from the PRV - it is from the exhaust - which I understand is normal (just condensation) - which leaves me with a problem - the fact is that they STILL need to pump up the expansion vessel annually - if not more regularly ...
Plus the leak (monthly topping up required) - presumably now from under the ground floor somewhere - but where ?

macman

You need to be much clearer about terminology here. There is no 'exhaust'. A condensing combi has 3 'pipes': 1) the condensate pipe (in white plastic, which should discharge to a gully or soakaway, 2) a PRV overflow pipe in copper, which just comes through the wall and is turned downwards, and 3) the main boiler flue (a much larger metal pipe), which discharges vapour only. You cannot possibly mistake one of these for another, they're all completely different.
You said that you put a bag on the PRV pipe and it collected water. Am I to understand that you actually put a bag on the flue?! If so, your boiler would not function, as the fumes could nor escape, nor would it be able to take in air for combustion.
If the PRV pipe discharges, then the PRV is defective and needs changing-end of story. If your RGI saw that discharge and says that nothing is wrong with the boiler then he is incompetent, and you need to get in someone who knows what they are talking about (and report him to WB).

50Twuncle

macman wrote: »

You need to be much clearer about terminology here. There is no 'exhaust'. A condensing combi has 3 'pipes': 1) the condensate pipe (in white plastic, which should discharge to a gully or soakaway, 2) a PRV overflow pipe in copper, which just comes through the wall and is turned downwards, and 3) the main boiler flue (a much larger metal pipe), which discharges vapour only. You cannot possibly mistake one of these for another, they're all completely different.
You said that you put a bag on the PRV pipe and it collected water. Am I to understand that you actually put a bag on the flue?! If so, your boiler would not function, as the fumes could nor escape, nor would it be able to take in air for combustion.
If the PRV pipe discharges, then the PRV is defective and needs changing-end of story. If your RGI saw that discharge and says that nothing is wrong with the boiler then he is incompetent, and you need to get in someone who knows what they are talking about (and report him to WB).

I will start again - with the correct terminology
Water drips from the FLUE - which I now understand is normal

Nothing drips from the copper PRV pipe (copper)

Water appears to discharge through the condensate pipe (although that is connected under the sink to the sink drain pipe (via an adapter))

The issue is that the boiler needs pressurising at least annually and needs topping up with water at least monthly
The lack of any stains on 1st floor ceilings tends to imply that, if we have a pipework leak - it is under the ground floor, floor....

bambibashercol

Top the boiler up to 1.5 bar and then isolate the flow and return on the boiler. Use levers underneath the boiler and leave it overnight.
This will prove if there is a leak on the pipework or the boiler.

50Twuncle

bambibashercol wrote: »

Top the boiler up to 1.5 bar and then isolate the flow and return on the boiler. Use levers underneath the boiler and leave it overnight.
This will prove if there is a leak on the pipework or the boiler.

Good idea !!!
thanks

macman

So you either have a leak on the CH circuit or a faulty EV. Did your installer actually check the EV?
There is a logical fault-finding process here that should make things perfectly simple.
If you rule out the EV and pin it down to a leak on the CH circuit, then that's where it get complicated, because the leak could be anywhere. The first place to check is the visible pipework, including the rad connections.

50Twuncle

macman wrote: »

So you either have a leak on the CH circuit or a faulty EV. Did your installer actually check the EV?
There is a logical fault-finding process here that should make things perfectly simple.
If you rule out the EV and pin it down to a leak on the CH circuit, then that's where it get complicated, because the leak could be anywhere. The first place to check is the visible pipework, including the rad connections.

He just ran the CH and commented on the angle that the exhaust went through the wall - at (asking if we had had any subsidence in the wall - I said NO - It had always been like that - since YOU fitted it - apparently it slopes upwards !!

He didn't open the casing - just watched the pressure - which (as expected) - stayed low - told me that we (probably) had a leak in the pipework and left !!!!

There are NO visible leaks in the system - no leaks around rads etc...

keystone

21Twinkle wrote: »

He didn't open the casing - just watched the pressure - which (as expected) - stayed low - told me that we (probably) had a leak in the pipework and left !!!!

Ummmmmm. In which case then:

keystone wrote: »

Perhaps time for someone else?

probably applies. 10 days this thread has been running now. Are you going to do it?

There are NO visible leaks in the system - no leaks around rads etc...

IF you have microleaks then you won't see visible evidence.

Cheers

50Twuncle

keystone wrote: »

Ummmmmm. In which case then:

probably applies. 10 days this thread has been running now. Are you going to do it?

IF you have microleaks then you won't see visible evidence.

Cheers

Yes I will - but how should I pick another company ?
This company are the only registered Worcester fitters for several miles and I don't want just any one turning up with a lump hammer !
As for leaks - the strange thing is that once the pressure is down to 0.8 bar (as it is now) - it appears to "bottom out" - ie not get any worse - does this tell you any thing ??

You say "microleaks" - but the speed of loss from 1.5 bar to 1 bar is not "micro" in my opinion - the amount of water that we need once a month is considerable (abt 10 secs of valve being fully open)