just fault finding on a friends CH system and looking for some advice.
Is it possible to by pass the roomstat to confirm that its the
3 way valve that is faulty rather than the room stat.
hot water but no central heating, pump is working and obviously once
the 3 way valve is pushed to manual and left there all is ok.
just wanted to confirm really that its not the roomstat.
Whats the best plan of attack in these cases please - your advice sort.