Hi, looking for some advice. My timer fired up my boiler this morning but my radiators did not heat up. Hot water was working fine.
I checked a couple of things. Found two of these (hopefully picture attached) only one, labelled as H/W had an operating light on. Once the boiler stopped I pressed the heating boost button and the second unit operating light came on and the radiators heated up.
It seems that if I have both H/W and heating I only get H/W but if heating is used independently it works fine.
Any suggestions?
