Ed Sirett wrote:
It's almost certainly the diverter valve inside the combi.
Make,model and date of installation would be useful.


Its a Potterton Combi 100 - installed approx 6 years ago I believe.


I think that model has a conventional water flow diaphragm and diverter
valve unit. I'm surprised that it is an intermittent fault though.

Its literally 4 times in the last 2 years (since we've been in the
house) for a max of 2 days at a time (3 of those times have been on a
Friday evening, conveniently (not) enough!!).

The water from the rad's is fairly grimy when I've vented them, so its
certainly not the cleanest system in the world. I'm sure some TLC
wouldn't go amiss. The radiators are a mix of old and new too.

Anyway, got a recommended plumber coming round next week. Shame it
will all be working fine by then though!!

Matt