radiators on all the time

Hi, we have a Boilermate (circa 1999) system and recently the radiators have been coming on even though the thermostat (Honeywell T40) is off and appears to be switching on and off ok. The Boilermate is set to summer setting, manual over ride on the mechanical clock is off. The system has 2 GrundFos pumps, we are in a hard water area but have had a Scalewatcher system fitted to the mains water inlet for a number of years - it seems like it could be a sticking 3 way valve to me but I can't see one, any ideas or help would be appreciated please.

Hi Paul

The symptoms you describe are exactly the ones relating to a sticking divertor valve. The unit you have is more than likely the Boilermate 3, and the divertor valve is located at the rear right hand corner of the unit (I know your Boilermate is round). It can be sometime tricky getting in to the area to undo/tighten the nuts where space is limited (I've even had occassions when I have had to remove the Boilermate to get to it when the developers installer has been a bit thoughtless).

I cover the Midlands should you need me.

Regards
Dave Hickey
Midland Boilercare Ltd
service@midlandboilercare.co.uk

thanks for that, much as I thought. Do you have to drain the system to remove it and can it be tinkered with or is it a sealed unit? BTW we're in Essex so are probably a bit out of area but thanks anyway. Regards Paul