Potterton Actuator msv322 motorised valve? HELP.......

10 May 2006
Reaction score
United Kingdom
My central heating is on even when heating switch is off and only water on. By searching web, i narrowed the problem to the actuator ( potterton msv322. Three port 22mm). The switch on top moves freely. With no change. So i was hoping just to change actuator for new one. I took it off and tried spinning valve by hand. This moves freely with water off, but with water on it won't move. Does this mean the valve is broken as well, or is the valve only meant to move when water stops flowing through it?
Sponsored Links
The spring return on the valve head should hold a wedge inside the valve body covering the ch port when hw only is on...yours doesn't block it off properly so you will almost certainly need to replace the body.
Replace the body complete with new head try honeywell or drayton 3 port valves as these are the best.
Sponsored Links
This bit:



Sorry for size but can't be bothered to edit.

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local