We have a recently overhauled pressurised heating system, with the big, red pressure balancing ball in the airing cupboard.
We know that the pressure in the system should not be allowed to drop below 1 bar and generally we fill it to about 2 bar.
However, we are finding that the system is losing about 0.25bar every week.
So far as I can tell, none of the TRVs on the radiators (or the return valves) are leaking. There are no tell-tale wet spots on carpets around any radiators. None of the seals seems to be weeping. There are no obvious signs of leaks showing through on the ceiling from where pipes might be leaking from the first floor.
So far, I've not left the system to see how far it drops, I've always topped it back up to 2 bar once it nears the dreaded 1 bar.
What's likely happening to be causing the drop in pressure and, short of having all the floorboards up on the ground floor to look for leaks there, is there anything else I can do to stop it?
Is this constant dropping in pressure normal or healthy? SHOULD I be trying to do anything about it?
The system has 14 rads (13 of which have TRVs) working off a Glowworm 18HXi boiler. I probably have to bleed a rad a little (1 of 2 or 3 usual suspects upstairs), every 3 weeks or so, but the pressure drops irrespective of this.
