Ideal Classic CH always on

[APD54]

I have an Ideal Classic FF270. When I trun the HW on the CH comes on too even if the programmer for CH is off and the room stat is at minimum. There are two solenoid valves in the airing cupboard (not a 3 way).

Any suggestions?

 

[namsag]

Heating motorised(asyou say solenoid) valve has stuck in the partially open position allowing heated water to pass to rad circuit......Sometimes can be freed but usually new valve req

 

[D_Hailsham]

There are two solenoid valves in the airing cupboard (not a 3 way).

Do you mean this type of valve?

View media item 11762
If so, they are motorized zone valves, not solenoid valves. One controls the flow through the radiator circuit, the other the flow through the hot water cylinder.

From your description, the heating valve is stuck open for some reason.

Disconnect the brown wire (this removes any power from the motor) and see what happens.

If the problem goes away, then power is getting to the motor when it shouldn't. This comes from the timer CH ON terminal via the wall thermostat.

If you still have the problem, there are two possibilities: the valve is stuck or the switch within the valve is permanently closed.

On most valves you can remove the actuator (box on top) to reveal the valve spindle. this should rotate easily, but only about 20deg from open to closed. If it is stiff, try a small amount of 3-in-1 or WD40. If very bad, you will have to replace the complete valve.

If the spindle is free, the problem is with the switch in the actuator. The contacts sometimes "weld" together. You may be able to free them and clean with glasspaper. If not, you will have to buy a new actuator.

 

[glasgowgas]

if you have a drayton lifestyle proggrammer this could be fritzed

 

[APD54]

Thanks everyone for advice. The offending valve is a Potterton MSV 222. I removed the actuator and easily moved the valve stem to the closed position. Like this I ran HW without CH coming on.

I have then checked movement of the actuator. It starts closed (spring loaded) and moves to open (vertical) when I put the CH and set thermostat up high. The only thing that seems wrong is when the actuator is in the valve closed position it doesn't look totally horizontal which could be allowing some leakage of boiler water into the CH system. Should the actuator be fully horizontal to shut the valve? Do I need a new actuator?

Thanks again

 

[namsag]

Yep new head req around £30