I have an alpha boiler with an intermittant fault. Now and again just before it fires up the RCD will trip. I have had my plumber test the pump ,gas valve , fan etc and all appears fine. As i said there is no time when this will definetaly happen (not funny when you are in the shower).

not good, December 2010

got a bit of a problem with the same boiler. its mounted in an airing cupboard with the flue out the top and through to the outside wall. it trips the rcd when the boiler ignites for heat on the startup. recently its had a new wall stat in the hallway. this isn't affecting the boiler. I am awaiting a call out from a boiler engineer whos alpha trained as the diverter valve is leaking on the flowswitch and wondered if that could be the issue. but even with the flowswitch out of the circuit its still tripping the rcd. everything else in the house is fine. just when the boiler kicks in. any ideas? was wondering about condensation in the thermostat inside the boiler.

Dan, January 2014

Hi, I have the same problem with the RCD tripping. I have a horizontal flue coming straight out from the bolier to the outside wall.
Is there a particular website to get flue extension kits from you could recommend?
Cheers

Keith, January 2011

had the same problem (advised by alpha, condensation dripping on to thermostat) our fix was to raise flue (it has a built in fall back) the condensation is on the outer tube..hope it helps

speako, December 2010