Glowworm Spacesaver No Heating

I was asked to look at a heating system the other day because the customer's central heating was not working. The customer could see that the pilot light on their Glowworm Spacesaver was alight but the heating was not working when the controls were calling for heat and the boiler was no firing up.

I tested the hot water and sure enough the boiler fired up and the system was running perfectly for hot water. I then turned the hot water off and put the central heating on and nothing happened. I checked in the junction box to make sure there was power on the grey and white wires to the motorised valve, which there was.

I then drained the system and replaced the Boss three-port valve with another motorised valve, refilled and heat tested the system and all was working well again.

Disclaimer: The works described in this blog are a record of work undertaken and should not be taken as guaranteed to solve your problem. Work should only be carried out by persons qualified and competent to do so.