Plumbing

2-way valve/wiring problem boiler firing by itself with no demand?

Anonymous user 03/03/2024 - 3.26 PM

Hello! I had a problem with my back boiler not providing central heating (hot water was fine) and the honeywell 2-way valve making a buzzing noise. Got an engineer out, before he arrived the boiler started firing up and running by itself even with the programmer not calling for any heating/hot water (both set to off on programmer). The only way to make it stop was to switch off the boiler/programmer at the spur. Engineer arrived, fitted new honeywell 2-way valve (no drain down). Switched boiler/programmer on at spur, boiler immediately fired up even though the programmer had hot water and heating set to off still. Heating and hot water now coming on together, even though programmer has both set to off! After some discussion with the engineer, I have an electrician visit booked for Friday as he suspects a wiring problem. However I have noticed that the lever on the brand new valve he fitted doesn't seem to move as it's supposed to when it's calling for heat/hot water? It's constantly midway between the AUTO and MAN markings whether boiler is on or off. Can anyone wade through this absolute mess and give me any hint of what is going on here?! The engineer said it's fine to use the (now on together constantly) hot water/heating by switching it on/off at the spur as needed until the electrician gets here, is this ok to do? Many thanks and much gratitude to anyone who can hazard a guess, or at least let me know if it's ok to use the heating and hot water for now! *Edit* I agree that the whole valve should be replaced, the engineer didn't want to do a drain down to do this and insisted the problem must be electrical! Thank you for this answer Mr Bateson.