Hi all,
Apologies in advance for the long thread, I'm trying not to go insane! I'm fairly sure there's a leak somewhere but before I shell out I just want to make sure it's not something simple and/or obvious that I can check myself...
I'm having some problems with the pressure dropping on my boiler, this is an ongoing saga! As a bit of a back story, we moved in to the house 18 months ago and had some work done to make an open plan area which meant a radiator was removed and capped off and a larger radiator installed.
After this we had issues with the boiler, the plumber used some leak sealer which was not effective. The plumber looked for the most likely culprit and found a leak in the capped off radiator, they did this by knocking a couple of bricks out, getting their hands in and fixing before refitting an air brick. All was well for a while.
During the past couple of months the problem of losing pressure has returned, we have British Gas Homecare included with our gas contract so I've called them out after checking all radiators and not seeing any signs of any leaks.
The pressure was actually rising when the heating was on before then dropping to zero over a few hours. This was immediately diagnosed as the expansion vessel which the engineer then charged up. This did not solve the problem. The engineer came back, fettled with the expansion vessel again and cleaned everything, including the Mag Filter attached to the boiler. Again no solution.
During all of this the heating and hot water was working fine. The only noticeable issue was air getting in to the radiators upstairs and causing noise. I was having to bleed the radiators every other day. Bleeding them often took a long time as a lot of air was in them!
When the plumber was investigating the issue 18 months ago he installed some isolation valves on the pipework which effectively isolated the downstairs heating pipes. I've isolated the downstairs using these valves and the pressure was fine, this would obviously point towards the culprit being a leak somewhere in the system.
I've had the same air brick out from last time and had an inspection camera in there, I can see quite far under the kitchen floor and a number of joints. There are no signs of leaks or dampness anywhere, it's very dusty and dry and no water coming out. However that doesn't mean there isn't a leak somewhere else on the downstairs system.
The British Gas engineer came back and used the leak sealer again to see whether it would help, it didn't. The boiler is losing pressure quicker than before, it's going down to zero in an hour or so. However, it did seem to temporarily stop air getting in the system, however I'm back to bleeding the radiators every other day. I have to top the system up twice to get the air out!
I've topped up the system and isolated the downstairs heating pipes again as a double check and the pressure stays constant over an hour or so, testing the heating going on and off. The pressure climbs from 1.2 to 1.5 and stays constant when heating on, drops back to 1.2 when heating off. When I've opened the isolation valves again the heating comes on and the pressure rises to 1.2ish and stays there. Once the heating has gone off, the pressure drops back down to 0 after an hour.
All this leads me to think there's a leak under the floor and I'll have to get a specialist trace and access company to find it (there's no crawl space). But I can't get my head around the following:
- The boiler still works as normal, besides air in the rads causing them to make noise and rattle.
- The boiler pressure will remain constant if the heating is on. It was explained to me that this will be due to the pipes being hot and expanding which may be stopping the leak. However there is no delay in this, if I were to put the pressure to 1.5 bar now when it was cold then turned the heating on, it would stay at 1.5, it wouldn't drop until it warmed enough to expand?
- Even after the pressure has reached 0 when the heating is off, the pressure will actually climb slightly, I've seen it go as far as 0.5bar from zero after the heating has been on for an hour or so? Surely the pressure would just continue dropping as it is losing water from a leak?
Is there anything else I can do to check before shelling out for a trace and access company?
Cheers,
Simon
Apologies in advance for the long thread, I'm trying not to go insane! I'm fairly sure there's a leak somewhere but before I shell out I just want to make sure it's not something simple and/or obvious that I can check myself...
I'm having some problems with the pressure dropping on my boiler, this is an ongoing saga! As a bit of a back story, we moved in to the house 18 months ago and had some work done to make an open plan area which meant a radiator was removed and capped off and a larger radiator installed.
After this we had issues with the boiler, the plumber used some leak sealer which was not effective. The plumber looked for the most likely culprit and found a leak in the capped off radiator, they did this by knocking a couple of bricks out, getting their hands in and fixing before refitting an air brick. All was well for a while.
During the past couple of months the problem of losing pressure has returned, we have British Gas Homecare included with our gas contract so I've called them out after checking all radiators and not seeing any signs of any leaks.
The pressure was actually rising when the heating was on before then dropping to zero over a few hours. This was immediately diagnosed as the expansion vessel which the engineer then charged up. This did not solve the problem. The engineer came back, fettled with the expansion vessel again and cleaned everything, including the Mag Filter attached to the boiler. Again no solution.
During all of this the heating and hot water was working fine. The only noticeable issue was air getting in to the radiators upstairs and causing noise. I was having to bleed the radiators every other day. Bleeding them often took a long time as a lot of air was in them!
When the plumber was investigating the issue 18 months ago he installed some isolation valves on the pipework which effectively isolated the downstairs heating pipes. I've isolated the downstairs using these valves and the pressure was fine, this would obviously point towards the culprit being a leak somewhere in the system.
I've had the same air brick out from last time and had an inspection camera in there, I can see quite far under the kitchen floor and a number of joints. There are no signs of leaks or dampness anywhere, it's very dusty and dry and no water coming out. However that doesn't mean there isn't a leak somewhere else on the downstairs system.
The British Gas engineer came back and used the leak sealer again to see whether it would help, it didn't. The boiler is losing pressure quicker than before, it's going down to zero in an hour or so. However, it did seem to temporarily stop air getting in the system, however I'm back to bleeding the radiators every other day. I have to top the system up twice to get the air out!
I've topped up the system and isolated the downstairs heating pipes again as a double check and the pressure stays constant over an hour or so, testing the heating going on and off. The pressure climbs from 1.2 to 1.5 and stays constant when heating on, drops back to 1.2 when heating off. When I've opened the isolation valves again the heating comes on and the pressure rises to 1.2ish and stays there. Once the heating has gone off, the pressure drops back down to 0 after an hour.
All this leads me to think there's a leak under the floor and I'll have to get a specialist trace and access company to find it (there's no crawl space). But I can't get my head around the following:
- The boiler still works as normal, besides air in the rads causing them to make noise and rattle.
- The boiler pressure will remain constant if the heating is on. It was explained to me that this will be due to the pipes being hot and expanding which may be stopping the leak. However there is no delay in this, if I were to put the pressure to 1.5 bar now when it was cold then turned the heating on, it would stay at 1.5, it wouldn't drop until it warmed enough to expand?
- Even after the pressure has reached 0 when the heating is off, the pressure will actually climb slightly, I've seen it go as far as 0.5bar from zero after the heating has been on for an hour or so? Surely the pressure would just continue dropping as it is losing water from a leak?
Is there anything else I can do to check before shelling out for a trace and access company?
Cheers,
Simon