Actuator or Valve problem?

[match]

I've got a BGMVSP-23 actuator (aka Drayton MA1) set up on my boiler system. I noticed the other day that some of the radiators were staying on when HW was selected, and that the hot water seemed to be less hot than usual.

Having taken the actuator off the valve and switched the controls, the actuator moves (slowly and with some clunky noises) between the 3 positions of W, M and H. Manually turning the valve with pliers to these 3 positions also works to correctly isolate the right bits of the system.

With the actuator is fitted to the valve, it will happily turn from W to H. However, when turning from H to W it seems to stop just after M. If I take off the actuator at this point (so there's no resistance from the valve) it completes the turn to W.

Is this a problem with the actuator (i.e. it should be more 'beefy' and be able to turn the valve), or a problem with the valve (it should be less 'sticky')? If its the valve at fault, is there any way to 'loosen' it or grease it? I'm happy doing electrical work, so replacing the actuator would be simple, but I'm not as keen to work on anything wet

Thanks!

 

[Agile]

Those actuators are not the best. The plastic gears may have worn or the motor may not be delivering the full torque.

The valve should move by finger pressure.

Sounds like a new head will be needed.

Tony

 

[match]

Thanks for that info - I'll look into replacing the actuator. Is the valve screw/couplings a standard fitting that will take any actuator, or do I need to purchase one of the same range/model as the current one?

 

[petit_pablo]

You will need to replace with a similar model drayton actuator head. Other makes will not fit on that body.

With the body itself, if you cant move the spindle with your fingers then its probably best to replace this as well. I find that as the spindle gets stiffer to turn it increases the wear on the actuator.