Hi everyone - a newbie here ! I returned home from holiday to find the house freezing ! The heating hadn't kicked in and I know from time to time air builds up in one specific radiator at the top of my hallway stairs about 5yrd from the boiler cupboard! I decided to tamper with what I now know to be the mid position valve (3 way) ! It went to heating by pressing the end plastic plunger! The heating kicked in ! I can get it to go to h -m -w with the plunger and depending how it feels it heats both or not at all! Is the valve the fault and is it a drain the system job ?

Thanks all who read !

Are you in the USA?

You are welcome

Take care