On Sunday, 29 January 2017 18:58:55 UTC, Roger Mills wrote:
On 29/01/2017 18:16, Roger Hayter wrote:
Bob wrote:

Correct me if I'm wrong but I think you might have changed the whole
head and integral gearbox.

yes

The individual motors within the heads are
also available as spares on ebay for £10-12 IIRC and should work as I
explained. You then can retain the old gear head with its particular
spigot arrangement.

But this is perhaps less useful when, as in this case, the problem is
stripped gear teeth rather than motor failure.



It depends on which teeth have stripped. There is a small gear on the
output of the motor assembly. If the teeth on that have stripped, a new
motor will replace them.

This small gear drives a larger (partial) gear connected to the valve.
If *its* teeth have stripped, a new motor won't fix it.

The problem has nothing to do with gear teeth or motor. The movement of the valve itself has become very restricted. So drain down & clean out seems the only option. If it turns out there is a persisting compatibility problem, hopefully I can fit the new base, which I still have, to match the new head. I hate plumbing.


NT