potterton 80 puma ch not working

Please can somone help with the following problem: -
I have a potterton 80 boiler and all of a sudden the central heating won't work properly. It starts up but goes off after about 25 seconds. The pilot light then extinguishes. The hot water is fine though? No problems with that.
Somebody mentioned that it might be the divertor valve? Are these expensive to buy. If so, is it posssible to remove the existing valve, clean it up and replace?
Perhaps it isn't the valve atall. I would be grateful of any help anybody can offer to me.
Thanks
K
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On Fri, 26 Dec 2003 00:33:18 +0000, Kirkjsmith wrote:

This fault is so common. You can check if there is the slightest drip on any hot tap as this can tip the balance when the diverter valve is almost broken.
I did see a trade advert for the diverter valve actuators in the summer (c. 20). I regret not framing it.
This means that you have to buy the whole unit (about 80) to replace the actuator on the end, but you might as well leave the old valve body in place.
HTH
--
Ed Sirett - Property maintainer and registered gas fitter.
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