motorised valve problem?

[mark306]

Hi,

A couple of radiators are staying cold when the motorised valve is set to CH & DHW.
If it’s set in the CH position the radiators heat to full heat.
I’ve replaced the pump and had a power flush and all radiators have been bled.
I have a three way Myson motorised valve (MPE322). It isn't the head as I've removed this and the problem remains when you manually set the valve.
It seems odd the valve wouldn't work in the in the CH & DHW "mid position" but the others are fine.

Any ideas?
Mark

 

[Agile]

The rads probably need balancing. See FAQ for details.

That is compounded because you dont apparently have a lockshield valve to balance the flow through the cylinder heating coil.

Ideally fit a gate valve is series with the heating coil and set it about one turn open to start with.

Tony

 

[ChrisR]

Or your rad valves could be stuck shut, especially if thermostatic ones.


Or need bleeding.