Motorised / Actuated Valve Faulty? Heating wont turn off?

Postby Garland » Mon Oct 22, 2007 8:51 pm


My heating will not turn off, irrelivent of thermostat position, or service selection switch on boiler. The motorised valve in the airing cupboard is not opperating. How do I know if it is the valve that is faulty and not some other part of the system? The valve was replaced at the same time as the pump in 2004.

If it helps the valve has 4 wires going to the circuit board gray, orange, white, and another one (I cannot remember but it went to the motor and I think it was blue!).

Thanks for any help you can offer.

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Simply Build It

Postby htg engineer » Tue Oct 23, 2007 8:36 pm

Isolate electricity supply, normally via a fused spur, next to timer.

There'll be two screws securing the actuator to the three port valve, remove these and the actuator will lift off, lie the actuator down on it's top or side and select heating and see if you can hear the motor and D shaped opening (where it fits onto three port valve) should turn. If it doesn't, then you will probably need a new actuator head.

Turn the three port valve spindle to make sure it is able to move freely.
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