locating a central heating leak, or can I just use a sealant

[jerrytaff]

I have a system with a combi-boiler. From the pressure gauge it is clear there is a leak - over a day the pressure (cold) drops from 1.25 bar to <0.5 bar. There is no sign of moisture anywhere. I deduce the leak is under the (ground) floor. Floorboards are covered with laminates, vinyl laid on hardboard, fitted furniture, fitted carpets etc, and even one section where the pipes were laid before the solid floor was completed, How do I locate the leak without ripping up all the flooring until I stumble on it?
Alternatively, would you recommend the use of a leak sealant or might that damage my Ravensheat combi boiler?

 

[ChrisR]

Check inside the boiler - locate the automatic air vent.

Be extra sure it isn't the pressure relief pipe. (Shove some tissue up it and leave it for a day)

Quite a leak that is, LS might work, have known it take 2 - 3 doses.
You could check with Ravers but I doubt it would harm it.