We've recently purchased our first home, and I have been updating the controls for the Central Heating / Hot Water.
Our original programmer/timer was the SwitchMaster 400, that allowed [Hot Water] or [Hot water + Central Heating].
We wanted to be able to control these individually and so purchased a Drayton LP722, which is now fitted and working.
However, When the Central Heating is signalled (without hot water) the boiler doesn't switch on.
I've traced this to the HSA3B triport valve that we have.
When Central heating is requested, the motor moves ALMOST all the way, just before the micro switch is activated inside the valve.
If you use the manual over-ride lever, and move it 1mm at most, the heating switches on as expected.
The actuator looks new, I've stripped it down and confirmed the switches operate cleanly, the gears are in good health, the spring is strong and all electrical connections are solid.
I can move the valve manually by hand without tools as well.
Is it likely the motor has given up its ghost? Or might there be problems with the valve as it will have not been used in a Central Heating only position from when ever it was fitted before we moved in?
Thanks in advance,
Conoral11
