What is a 3 port valve (mid position valve) why do radiators come on with hot water intro
19:26
Central Heating - How the mid position Y plan 3 port valve works
11:27
2 Port Central Heating Zone Valve CUT IN HALF Pt.2
7:40
Mid-Position Valve - How it works
12:01
How to Repair a Motorised Central Heating Valve
2:30
Various ways to identify a faulty motorised valve
17:47
How to test 3 port system wiring for issues. Reference Sheet at End of vid
11:17
Why Are Your Radiators Getting Hot When the Heating Is Off?
9:08