BGMVSP-23 Mid-position actuator sticking

[ghobbs]

Hi. I've got this problem with my HW/CH 3-way valve. When the HW is selected the CH partially comes on as well. In testing the actuator, the indicator lever on the side of the actuator can move to M (mid) and C (central heating) positions, but it doesn't seem to be fully moving to the W (hot water) position.

I've removed the actuator from the valve body and tried to turn the spindle with a spanner. Again, it doesn't seem to want to fully turn to the position that would be the W position. If I force it a little then it moves, but then springs back once I release the spanner force.

So, I'm thinking that perhaps the valve is faulty. Perhaps there is some debris stuck in the workings of the valve that is preventing full operation. Or, is the valve designed to be turned with a higher torque, so perhaps the actuator is not working correctly?

If I need to replace the valve, then I understand that I need to drain the system. Or, could I freeze the 3 pipes around the valve and replace it that way? What would people recommend?

Any help much appreciated.

 

[45yearsagasman]

There is only approx 20 deg of travel on those valves. Try closing the ch port with the head removed, but use only gentle force to keep it closed. If that proves ok then maybe just a change of head will do the trick, as the return spring may be weakened. Does the spindle move freely by hand?

 

[ghobbs]

Thanks Pete. Yes, that 20 deg makes sense. The spindle moves freely, no sign of anything wrong. I will try what you suggest.

 

[petit_pablo]

Generally ive found that if i can move the valve spindle with my fingers its ok and only the head will need changing. If it will only move with a spanner then the spring in the motorhead isnt strong enough to overcome that and the body needs changing.

Alot of the BG/Drayton heads that wont spring back to W have snapped the little peg the spring latches onto. Turn the power off and remove the plastic cover. Both springs should be anchored on opposite corners.