Motorised valve sticking open.

Hedgecutter

Hi have a danfuss motorised valve that is sticking open and switched on. The heating humbs while this happens and is annoying. Is there any way of freeing it up, could I spray it with WD or something similar?

John.G

Assume its a two port valve. If you are happy that the actuator has no power and its still open which will fire the boiler with the end contacts then you can remove the actuator, if the actuator is the problem just power it on/off and see if it opens/closes (while removed) if it doesn't then you can buy a new actuator and fit it, if the actuator is OK just turn the valve spindle with a pliers a few times, generally these take very little force to operate, a drop of WD40 may help. If its a 3 port mid position valve then I would suggest changing the complete valve, including the actuator.

Hedgecutter

Ya it's a two port and it's the actuator that's the problem. I usually hit it lightly with something and you can hear it close. New actuator so? A little spray on the actuator work?

youtheman

Only suggestion I would make is to check that the problem is not with the limit switch itself. I had problems with my zone valves (think they were Myson) whereby the limit switch came loose in the housing and continued to give the wrong signal. I just had to use tie wrap on the switch to secure them in place.

JamesM

https://www.boards.ie/discussion/comment/117897985#Comment_117897985

Read John Gs post again. If a tap usually loosens it, then it's likely the spindle that is stuck. Take off the actuator and turn the spindle a few times to loosen it.

John.G

Agree but suggest also powering the actuator on/off while removed from the valve.