"xtinexoop" wrote in message
om...
Hi

We have a problem with the central heating. I think we have narrowed
it down to the motorised valve which is a Myson 3-Port valve.

The problem is that although we have hot water the heating doesn't
come on unless you use the manual override lever. We can see from the
lights on the actuator that the timer control is passing the right
'signals' to it, but it isn't opening the valve.

I had a look on the Myson website and it is possible to buy the
'actuator' bit seperately and its 4 screws and some simple wiring to
replace which having taken the current one off to have a look I think
I could manage. The alternative would be to buy a complete new valve
but I understand that would require draining the system and would be
beyond my capabilities and expensive to have done (a quote to replace
it with a Honeywell valve is £150+VAT).

Can anyone tell me whether it would be false econonmy simply to
replace the actuator - is it like replacing the disks in a car and not
getting new pads at the same time for example?

Any suggestions gratefully accepted.

Thanks


Christine

Hi Christine,

You can buy the individual parts which sit inside the valve head at a
fraction of the cost of buying the whole thing, and they are very easily
replaced.

Test the microswitches to see if they are passing the voltage signal along
to the other parts of the system.

example of a microswitches he http://tinyurl.com/opo0

Make sure that the synchron motor is running when you make a call for
heating (switch the system on) and is opening the valve.

example of synchron motor he http://tinyurl.com/opoc

The parts used inside these valve heads are pretty universal, mainly because
they all come from the same manufacturers, and they only cost pennies
compared to buying the whole head part. Try looking around your local
repair shops for them and save yourself a good few pounds.