Central heating system has been losing pressure for a few weeks now. Pressure drop varies from day to day, can be as much as 0.7 bar or as little as 0.3 bar.
Have checked the “overflow” pipe and that is dry as a bone, put a plastic bag over it just to double check. So assume the PRV and expansion tank is OK.
Don’t get clouds of steam out of the flue so assume that the heat exchanger is OK.
Have checked all visible joints and radiators and no leaks there.
So assume that most likely a joint under the floor is leaking. Have checked the ceilings and no visible sign of damp. No sure how much water lose it takes to reduce pressure by 0.7 bar and whether that would show up on the ceiling.
A few year back I put new flooring upstairs so can’t just lift a floor board to check those joints. Did move a radiator at the time and had problems getting water tight compression joints so used silicon jointing compound. Thus quite likely that one of those joints has now failed.
As first recourse going to try leak sealer. Whats the likely chance of it working?
The price seems to vary a lot.
No Nonsense Leak Sealer 1Ltr £2.36
No Nonsense Leak Sealer Tube 310ml £2.99
No Nonsense Central Heating Leak Sealer 500ml £9.19
Sentinel Internal Leak Sealer 1Ltr £9.99
Fernox Heating Leak Sealer Concentrate 500ml £13.99
No Nonsense Central Heating Leak Sealer 310ml Concentrate £14.92
Sentinel Rapid Dose Leak Sealer 400ml £14.99
Fernox Heating Leak Sealer Superconcentrate 290ml £24.99
What is the difference and what is recommended?
Have heard of sealers causing damage to combie boilers so best to drain/flush the system to remove the sealer after it done its work or leave it in to seal any future leaks?
Thanks.
One other question does it damage the boiler if its run on low pressure say around 0.2 bar?
Have checked the “overflow” pipe and that is dry as a bone, put a plastic bag over it just to double check. So assume the PRV and expansion tank is OK.
Don’t get clouds of steam out of the flue so assume that the heat exchanger is OK.
Have checked all visible joints and radiators and no leaks there.
So assume that most likely a joint under the floor is leaking. Have checked the ceilings and no visible sign of damp. No sure how much water lose it takes to reduce pressure by 0.7 bar and whether that would show up on the ceiling.
A few year back I put new flooring upstairs so can’t just lift a floor board to check those joints. Did move a radiator at the time and had problems getting water tight compression joints so used silicon jointing compound. Thus quite likely that one of those joints has now failed.
As first recourse going to try leak sealer. Whats the likely chance of it working?
The price seems to vary a lot.
No Nonsense Leak Sealer 1Ltr £2.36
No Nonsense Leak Sealer Tube 310ml £2.99
No Nonsense Central Heating Leak Sealer 500ml £9.19
Sentinel Internal Leak Sealer 1Ltr £9.99
Fernox Heating Leak Sealer Concentrate 500ml £13.99
No Nonsense Central Heating Leak Sealer 310ml Concentrate £14.92
Sentinel Rapid Dose Leak Sealer 400ml £14.99
Fernox Heating Leak Sealer Superconcentrate 290ml £24.99
What is the difference and what is recommended?
Have heard of sealers causing damage to combie boilers so best to drain/flush the system to remove the sealer after it done its work or leave it in to seal any future leaks?
Thanks.
One other question does it damage the boiler if its run on low pressure say around 0.2 bar?