Roger Mills wrote:
On 21/08/2010 20:57, DavidA wrote:
Hi

A Honeywell V4043H1056 2-port motorised valve in our CH system has
stuck. I suspect that the synchronous motor has failed.

A replacement Honeywell motor seems to cost around £25. Screwfix do a
Drayton motor for around £13 (page 420 of Spring 2010 catalogue),
which is supposed to fit many valves.

Please can anyone advise whether the Drayton motor is suitable for
this Honeywell valve?

It's probably the same motor - there are very few sources. If Sf says
it fits your valve, it will be ok.


I did see a post on another forum ('diybanter') that stated:

"Change the motor (for Honeywell, they recommend you get a Honeywell
motor as it they are more robust as their valves can remain open
(i.e. powered) to CH if that was the last demand, even if demand has
now ceased, therefore more wear on the motor)."

Is this really true? I would have thought that a microswitch would
stop the motor when it has reached position.


The standard 2-port valve has a spring return rather than being
motored both ways. In the open position the motor is still powered
and runs stalled. When the power is removed, the spring closes it.

I have just been looking at this post. It seems that the same motor is used
in both 3 port and 2 port valves. That is something that I had never
considered before.

Of course the problem with the 3 port valve is explained here

http://www.diyfaq.org.uk/plumbing/co...itionvalve.htm

In a 3 port valve the motor could be held in a stalled position for months.

--
Adam