Pressure dropping / leaks

[gordie]

Pressure is dropping on our combi boiler to below 0.5 and a couple of radiators upstairs fill with air, so we refill boiler and bleed radiators. Same thing happens every few days and I think we've got a leak.

Problem is that downstairs radiators are under concrete or under wooden floors (we'd know if upstairs was leaking). Is it possible to "isolate" each radiator to find out exactly which one is leaking before we start to dig up floors ?

Any suggestions would be most welcome.

 

[bab]

Before any major work try to eliminate the boiler as the problem. if you set the pressure on the boiler @ 1 bar after running the heating does the gauge rise fast or do u notice any water leaking outside through the pressure relief pipe when the boiler is running.

 

[gordie]

Thanks for your reply.

No, the pressure release valve is not leaking at all and gauge does not rise fast.

 

[bab]

I'm not douting u but do check both . The leaks probably on pipework downstairs. u r probably loosing 1/2 to a pint a water a day so it should be showing some where if it was above ground. it depends how your downstairs pipe work is fed but it will have to be isolated step by step to find it.

 

[gordie]

Thanks - I have checked both (in fact I've been watching the pressure gauge for a few weeks).

I'll have good look round for signs of leakage but we recently had an extension and much of the pipework is below concrete or below tiled floors.

Do you know if it's possible to isolate radiators until we find which one is leaking, as it's an impossible (or at least very expensive) job to check them all ?

 

[Bahco]

Put isolaters on the 2 pipes just before they enter the concrete and turn off.
If the pressure remains sound, you have found your source of leak.

Bet you are glad you have buried your pipes.