On Sunday, 29 January 2017 15:26:30 UTC, Bob Minchin wrote:
tabbypurr wrote:

35 year old 3 way valve had stripped its gearteeth, so the head was replaced with an identical one. Or so I thought. The new one won't work though, it stays on HW only all the time. Taking the head off reveals that the socket that engages onto the valve shaft sits at a different angle, so that at one end of the head's travel, the valve is at the other end of its travel.. Hence any control of the valve is impossible, it sits at one end only. Any ideas before I copy Simon?


NT

When I had one that failed (2way) it was the motor pinion that had
dental decay and so a new motor sorted it out. It only has about 8 teeth
and so much more subject to wear

If your gear wear is elsewhere then you might have to bite the bullet
and fit a new valve. Sometimes there are new valve bodies on ebay to go
with your replacement head to save buying a whole new valve.

That's what was done. And I explained why it hasn't worked.


NT