"Neil" wrote in message
...
Hi,

I have a problem with the radiators being hot when the hot water only
option is selected.

I have taken the motor assembly off the diverter valve to expose the
shaft as i suspected the valve had jammed.

Grasping it with the mole grips it seems very free between 1130 and
1230 on the clock, if you see what I mean....it rotates about 20
degrees, but then its solid in either direction. This isn't right is
it ? Should it go right round 360? 180?

I don't want to force it.


Neil

Some might tell you that the shaft does go right round, but in my experience
they don't. If you look at the 'T' shape of the pipework you can see that a
valve - which may be a ball on a stick, or a 'v' shaped piece of hard
rubber - only needs to be moved a relatively short distance. Don't force
it, or the actuator assembly might not go back on in the right position.

Just check that when as far as it will go on one side the CH only pipe gets
hot; when fully the other way only the hot water pipe gets hot. If that's
the case. it is almost 100% certain that the microswitches in the actuator
have burned out and the thing has defaulted to the mid position.

From my thread on the same subject you will see this is an extremely common
and annoying occurrence, and the replacement actuators all seem to be made
the same crappy way and fail after a relatively short time. It is - if you
are handy with a soldering iron - possible to replace the microswitches in
the actuator, but therest of the mechanism is so fussy, that even then it
can be difficult to get the thing to balance at all three positions.

The problem typically shows up at this time of the year when people expect
their rads to be cold and find they are not, but during the winter it also
means that your rads never get the full flow of hot water and you waste vast
amounts of time trying to balance rads or even replace pumps before you
finally realise what is inside that curious little box with the wire coming
out of it...

See if anyone comes up with a reliable actuator on my thread, otherwise, a
new and probably rubbish Danfoss seems to be going for around £35 at the
mo - which incidentally, is a fair bit cheaper than the last one I had to
buy.

S