The filling loop has a tap either end and both of these are in the closed position.
When you say the fan gasket, do you mean the the gasket around the edge of the chamber cover, if so - yes.
So what do you think the problem is?
over the past couple of years I've fitted a new Grundfos pump and new Vokera fan unit (which cured a few problems). The two micro switches that operate off the valves appear to be working - point me in a direction please.
I think I've sussed the extra pressure issue - my next door neighbour has been having some major plumbing work carried out and because we are a large house split into two, somehow we share some of the water system and if they change their pressure it affects us (we had trouble in the past).
I...
Had my shower this morning, turned it off, wife went to take shower a few minutes later and no hot water.
Went to check boiler and pilot light on but not fired up. I noticed the pressure was up to 3.5 Bar and as the 3 Bar had a red indicator by it, I wonder if the boiler had a failsafe device...