Brittony Combi 80 Keeps Cutting out

[tcreedy]

I have a 5 year old brittony combi 80 and for the last 2 days it keeps cutting out. When you turn on the hot tap it works fine for a min or so and then the boiler cuts out. The power light stays on but becomes alot dimmer and the water goes cold. You then have to turn it off at the isolation switch and wait for a while then turn it back on and it will work again for a little while before cutting out.
Any ideas would be greatly appreciated as this is driving me mad.
Thanks

 

[kevplumb]

whilst i apreciate this may be a bit tecchy
the dhw h/e is full of crud

on the primary side

 

[bones001]

what i would do is take the front off, and on the left hand side you will see a plastic thing with a load of wires connected to it, thats the diverter and they are prone to sticking. whack it with a screwdriver a good few hard hard times until your dhw pipe starts runnin hot

 

[tcreedy]

thanks very much for your replies will get husband to have a look and see what he can do this weekend.