A new combi boiler was fitted a few weeks ago. Prior to this, the presure on the old Combi boiler dropped to zero every few days. Unfortunately the same problem is still with us and we have to top up the pressure every few days. We have checked all valves and joints on the pipework, but can find no evidence of a water leak.
Is there a way of finding where the leak is?

John Mercer, October 2009

Just a thought - if your CH system is on, ie hot, water will evaporate from any leak more quickly and the leak will be more difficult to find. Good luck!

Threadbare, October 2009

The pipework was not renewed, The property is a bungalow, so only one floor is C/H. We have had all carpets and floor boards up, checked all joints under the floor, but there is no trace of a leak. I was afraid to use a leak sealer in case it would void the guarantee on the Wolsey Boch boiler. Is there any other way of detecting this leak?

John Mercer, October 2009

you didn't mention if all pipework was renewed, under floorboards for instance, if not that's probably where the leak is, have you noticed any patches on ceilings?, one thing you could try is central heating leak sealer which you can get from a good plumbing centre, this works quite well if the leak is not too severe.

tojo, October 2009