system pressure?
my vailent combi looses pressure every day but i cannot find a leak anywhere. none from the relief valve and none from any rads pipes etc. a small section of pipework is underfloor ( concrete ) but cannot see any evidence of leaks. lots of new parts for the boiler but no change to the pressure losses.how else can i be loosing this much water every day without finding it.
steve, October 2009
