Cleaning / servicing a 3 way valve.

[Ant1]

I installed a Sunvic MK1453 (3 way valve) around 2 years ago, however the internal mechanism often gets stuck when trying to reach the hot water position. I opened the valve and cleaned it using a plastic brush (as shown in the photo below) not to make any damages:



It worked for a bit but the mechanism is still getting stuck. When it happens, if I tap the 3 way valve (not the actuator), it frees the internal mechanism and it rotates to the required position. If I remove the actuator and try to move the mechanism by hand, I can notice it is quite a bit stiffer than when it was brand new.

Is there a way to clean the internal mechanism of a 3 way valve effectively without causing any damages? I would like to give this a try before having to fork out another £70.

Basically I would like to make it move smoother but I am worried I cause more damages if I use fine sanding paper.

PS: I am also not sure if I can start using product such as WD40 in my system, might be pretty pointless as the water would just remove most of it right away...

Thanks,
Ant

 

[slowdown ave]

iv'e read you should use silicon not wd

 

[Madrab]

Typically 3 way valves do wear out but more so the motors/switches but the valves themselves tend to last for quite a long time, if it's getting sticky though then it'll probably be the spindle that is getting worn out. Lubricating will work for a time but eventually it will just go back to the way it was and undoubtedly get worse. Was it a good quality valve or a cheaper clone?

Probably time to replace TBH.

 

[gas112]

have you tried slightly unscrewing the bolts that hold the head to the body . if they are too tight it can cause this problem on these valves

 

[denso13]

8 year old thread.