When I read the op’s first post mentioning that the pressure dropped to 0.5 bar I also thought of a perforated HWC coil, however the post does not make clear whether the pressure always settles to 0.5 bar or would eventually go to zero.
With the system not isolated or running in any way...
You can save some money by reusing your existing programmer and just moving it to the airing cupboard. If you are doing this then the heating channel can be disconnected.
Again as G4Y says, it would be better to get someone who knows how to do all this in as once you disconnect everything I...
As gas4you said, have your existing programmer on 24/7 for heating and the new programmable stat will take over. Hot water is not affected. Make sure you know how to wire the thing in properly.
Neither. It causes the motorised valve to operate which in turn will fire your boiler and possibly the pump, depending on what sort of boiler you have.
Ah yes I see. Several minutes after someone else identified the problem, I immediately knew what the problem was. I am only surprised that no one else, apart from me, knew the answer. Everyone else has the IQ of a toffee apple.
Not sure if I understand your post as it was making my eyes hurt, but this might answer your questions:-
1) Should not do any harm to manually operate the valve
2) If you are talking about resistance across the windings then I dunno
3) No special settings to replace the motor
Apologies...
Not at all but it seems to me that the OP is going to have to get formal to get any satisfaction on this one.
If he eventually goes down the small claims route then he must show that he has made every effort to enable the original contractor to rectify the work.
The judge would be...