Ravenheat 802/20 Hot water problem

[dc6839]

Suddenly the hot water output on my Ravenheat 820/20 has stopped. When drawing hot water the main burners do not ignite. However if I turn up the room thermostat so that it turns on the central heating the main burners ignite and I can get plenty of hot water. The radiators are cold for as long as I draw hot water but get hot as soon as I stop using hot water, so the central heating side is working well.

Any thoughts on the problem and how to recitify please ?

Thanks

 

[picasso]

there is a diapragm in the divertor valve which is probably worn or stretched, needs to be replaced.

 

[Agile]

On that model its a knuckle scraping job to remove/repair.

Furthermore the large nut can be very difficult to remove now they are 16 years old.

Tony

 

[dc6839]

Thanks for the informative replies.

Is changing the diverter valve something that I can do ? I know, you have no idea of my capabilities but I am good with plumbing having installed the complete central heating system some 11 years ago (only the water side as the gas side was done by a Corgi guy)

Thanks again

 

[Agile]

In theory you could do it yourself.

But if I find it a difficult job even when I have a selection of tools and experience of the problems, then I would suggest that you think twice about doing it.

Tony