Recent content by MarkDavis

Thanks to both for helpful replies. It's a Glow-Worm Space-Saver 75, installed around 1984 (yes, I know we should have replaced it, but it keeps working and a 1-for-1 replacement by condensing boiler isn't that easy because it's mounted on an inside wall). It does seem likely that the boiler...

I have a conventional CH system: gas boiler, Grundfos pump and 2 Honeywell motorized valves controlling separate circuits for radiators (with thermostat-timer control) and HW (timer control). Here's my problem. The motorized valves close, the pump stops and the boiler shuts down as normal...