Motorised valve issue?

[L_Plate]

I seem to be having a problem with the motorized valve on my CH system. All of the rads have failed to come on but hot water is still plentiful. I switched the manual lever on one of the MVs and this did the trick of bringing on the pump and moving heated water to the rads. Presumably the mechanical side of the valve is functioning correctly, so I am assuming that it is the actuator in the MV or indeed the programmer? Can anybody please recommend what steps I should take to determine which item has failed? Thanks very much in advance.

Also, is there a problem just leaving the lever manually switched. Cheers.

 

[seco services]

sounds like the motor has gone in the valve

 

[kirkgas]

the only prob with manually opening the heating valve is that you will have heating when you only want hot water, but no safety issue, i would advise turning on the timeclock to call for heating then check (if competent/capable/have proper equipment) if 240v at zone valve if no then timeclock (or room stat faulty, check for 240v at room stat) if 240v at zone valve either faulty actuator or valve,

 

[L_Plate]

Thanks very nuch, guys.

Have carried out the test with the multimeter and there is 240v available at the MV. Is there any way of determining as to whether it is the actuator or the motor? I am assuming here that the valve is not defective as it can be operated manually using the lever. Thanks again.