Gents
I've checked/done what you both suggested, in particular:
1. I left the boiler on but didnt use the HW or CH and put a bag over the end of the condensate pipe. It didnt fill with any water and the boiler still lost pressure. The bag did fill when you put the HW/CH on and it starts...
How much leakage is needed from a central heating system before it loses pressure?
We have a Saunier Duval Thema Condens f30e combi boiler (fitted 2006)that loses pressure in matter of hours after refilling the system. System feeds a 3 bed Victorian house (8 rads).
We've tested the prv...