Honeywell 3 port valve Problems!!

[haydencookdonna]

Problem is I can only get heating, when tank stat is calling for hot water. I've got a Baxi Solo, with Drayton controller, and Honeywell room and tank stats, and a Honeywell mid position 3 port valve. Thought the valve may be sticking, so removed the head, and the valve with pliers moves freely. when moved over makes no difference, to heating or not. Voltage to room stat ok. Voltages at 3 port as follows.

ch+hw on White 234v Green 51v Orange 237v.
ch+hw off W 3v G 240V O 77v.
Hw only on. W 5.7v G 240v O 77v.
Ch only on. W 240v G240v O 80v.

Motor on head seems to move when not attached to valve body.

It's freezing, and i'm fed up drawing off hot water every hour or two, to fire up my heating system. Help Please!!!!!!!!! Thanks in advance. Greg

[gas man]

call in a pro mate your valve has died

[doitmyself]

Voltages at 3 port as follows.

ch+hw on White 234v Green 51v Orange 237v.
ch+hw off W 3v G 240V O 77v.
Hw only on. W 5.7v G 240v O 77v.
Ch only on. W 240v G240v O 80v.

Presumably you mean Grey, not Green.

The actuator is faulty - that's the box on top of the valve.

You can replace the actuator on its own. Cut the cable without disconnecting the wires, then you will know where they go when fitting the new actuator.

Any plumber's merchant will stock the actuator.

[haydencookdonna]

Yes Sorry! I meant Grey and not green. If the actuator is faulty, why does removing it and moving the valve with pliers manually not ake a difference? Thanks. Greg

[clydey]

according to honeywell site faultfinding guide on mid position y plan
suspect the v4073a valve is faulty only if the valve does not operate as specified in the following checks.
Valve open for heating only
procedure
switch off mains supply.
disconnect grey and white wires from appropriate junction box terminals.
reconnect both grey and white wires to permanent live in junction box.
switch on mains supply,
valve motor should now move to fully open heating port A.
the motor should stop automatically when port A is open, and stay in this position as long as power is applied to white and grey wires.
when port A is fully open , the orange wire becomes live, to start pump and boiler.
double check by feeling that port A is getting progressively warmer.
hope this helps as although fully qualified sparks and done a honeywell course ive still to get to grips with these plans as i do not get to work on them often cheers

[doitmyself]

If the actuator is faulty, why does removing it and moving the valve with pliers manually not make a difference?

You said that all you can get is heating when the tank stat is calling.

A quick explanation:

HW only - boiler lit from cylinder thermostat Call terminal
HW and CH - boiler lit from cylinder thermostat Call terminal
CH only - boiler lit from orange wire

You will find that there are three wires to the same terminal: Cyl Stat Call, Valve Orange and Boiler ON.

The reason you can only have CH with HW is that the voltage on the orange is only 80V, which is not sufficient. The solution is a new actuator.