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I am having a problem with the motorised valve on my Worcester 15/19 heatslave boiler. I always seem to have hot water but the heating does not always come on,also for no apparent reason the radiators get very warm for a short periob with the boiler not firing(usually after running the hot tap. If I move the manual lever on the back of the valve to manual lock it is against resistance and the radiators heat up. When releasing the lever it only moves back to about 50% of the slot, if I move it to the end of the slot it feels as if it is disconnected, there is no resistance. Should the lever move to the end of the slot? Also should I be able to see the lever move when heating or ch is required. A new PCB has been fitted but the problem still persists.
Any help would be gratefully received
Alistair

Alistair,
I asume you have eliminated problems with your thermostat and CH controller. If you can move the manual operator it is unlikely that the problem is with the plumbing side of the valve. If the valve is relatively new you can fit a replacement head without draining down the system. Make sure you check how many wires go into the valve it is usually 6.
end

Hi there
Thanks for coming back so quickly. I had already checked the controller and thermostat and decided to replace the motor on the diverter valve.
I arranged for local plumber to do this job as its a pig to get to.
He noticed that the automatic check valve was venting and then found that when the schrader valve on the expansion vessel fitted to this type of combi boiler water was operated water came out not air!. He replaced the expansion vessel, checked the operation of the motorised valve and every thing was ok. Just as well I got him in otherwise I would have replaced the motor /valve and the problem would have still existed.
Many thanks
Alistair

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