2 port valve partial fault

14 May 2004
Reaction score
United Kingdom

I have a honeywell 2 port valve. When the hot water is called for, the synchron motor works and opens the valve but the lever stops just short of the micro switch so the boiler does not fire up. If I give it a little push with my finger the hot water comes on.

I was going to replace the whole head but doing the motor would obviously be cheaper. Do these motors ever partially fail like this? I have only heard of them either working or not working so thought it might be an issue with the valve being sticky towards one end?
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Unless it is a very old valve, you can remove the head. Check by feeling for the raised dimple on the top. If there, move the lever to the manual position and undo the two screws that retain the head. this gives you access to the valve stem; this should move freely over about 50 - 60 degrees. If there is evidence of leakage or corrosion, the whole valve will need to be changed. In the short term, using pliers or grips, operate the valve and give it a spray with WD40 or other lubricant. If you try to operate the head away from the valve, you will find it slips. This is not a fault unless it slips when fitted.
Thanks oilhead.

I just took the head off and the valve stem seemed a little stiff about halfway. I worked it a few times with the pliers and it loosened up. The head is back on and it seems to be working perfectly at the moment. Hopefully is won't seize up again.

Thanks for the tip.
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If WD40 has done the trick, I'd put a couple of drops of 3in1 or other light oil on it as well. WD40 has its uses but will dry out quite quickly when the system is working, oil wont.

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