HELP NEEDED PLEASE!! C/W not working but water hot!!

[8valverpaul]

Turn the cylinder stat down and the room stat up and select the heating and hot water. The valve motor should allow flow to port A and the lever will have no resistance. If this doesn't happen the motor may be dead.

This however still doesn't explain why there is no flow when the heating is selected.

The small MV lever has no resistance in any position!?!?! Only at the very end of the movement when putting into manual!! The CH system looks like its working when I leave it in manual, does this point to the MV being knackered??

 

[Gasguru]

If there is resistance felt when putting it to manual with the controls calling for heat the motor is probably stuffed.

Put your thick marigolds on (you are an electrician). Take off the actuator top and test for 240v AC accross the motor with a call for heat.

Remove small screw and remove motor. The small cog should be imposible to stop turning if the motor is OK. Remember the motor is not earthed once removed from the actuator.

 

[8valverpaul]

Cheers mate i'll try that tommorrow (hopefully) and let you know how I get on with it!!
Cheers again for all your help, its very much appreciated!!

 

[8valverpaul]

I hav'nt managed to test the valve motor but I have got hold of a new pump relatively cheaply and i'm gonna replace the Honeywell MV (V4073A) aswell!!
I've left the system in manual and everything is working fine so I reckon this should solve the problem!! Whatya think??