What is a 3 port valve (mid position valve) why do radiators come on with hot water intro
7:42
No heating? Check the motorised valve.
7:40
Mid-Position Valve - How it works
3:06
Radiators Coming On With Your Hot Water (Even With The Heating Off)? This Is The Cause
19:26
Central Heating - How the mid position Y plan 3 port valve works
12:01
How to Repair a Motorised Central Heating Valve
11:27
2 Port Central Heating Zone Valve CUT IN HALF Pt.2
17:47
How to test 3 port system wiring for issues. Reference Sheet at End of vid
9:08