We have a Potterton EP2000 contoller but that seems ok. I think I've isolated the fault to the diverter valve behind the hot water cylinder. Seems its sticky and a bit of pressure on the actuating arm completes the elec circuit for the boiler to start up.

Can I just replace the diverter valve with a new one? Is that a diy job? Would I need to drain the system?

Richard M, September 2007

If the zone valve is a pig to get at it may be worth while trying to replace just the motor on the valve. Works a treat on a honywell two way zone valves. These motors are called synchron motors and you can get them on ebay for around £10 you will pay a bit more at Plumb center the beauty is that there are just two wires to connect . If you live in a hard water area it may be worth replacingthe whole unit.

Tony, September 2007

they can be a pain if you change the whole unit make sure you change the wires one for one as their is 5 wires and if you pull them all out you'll be having fun.

hi-spec plumbing, September 2007

Thanks Mr Hi-Spec
I only wish you had installed my system - I'm sure you wouldn't have put pipes across the front of the motorised valve. The pipes are so close I can't take the powerhead off the motorised valve! Ah well! - (not what I said just now though!)

Richard M

Richard M, September 2007

yes you can replace and drain the whole system below the valve

hi-spec plumbing, September 2007