How do you use F4 leak sealer through filling loop. Not sure if I have to drain the system down and which end of the filling loop do I disconnect? Got a leak in pipe which I can hear but cant locate as hidden behind a wall, want to try this before I have to demolish half my living room wall. Already lifted 3 floors upstairs trying to trace it.

Rockchick, November 2009

Its losing pressure over a matter of hours, 1 + 1/2 bars over 5 hours or so, but when heating is kept on permanent, it is staying pressurised quite well. I have now found a drip coming from the boiler as well, so that will be causing loss of pressure as well. Was hoping sealer would give me at least a short term fix. Thanks for answering.

Rockchick, November 2009

If you can hear the Leak then a lorry load of leak sealer will not work save your cash and demolish the wall and fix the leak properly, F4 leak sealer is for Very small leaks only i.e pressure going down after a couple of days, it soundss like your system is loosing pressure after a couple of minuites!!

www.elanar.co.uk, November 2009