Hot Water Not Working

The central heating is working, but the hot water is not heating. I switched on the hot water at the timer, and had a look in the airing cupboard. There were two zone valves, and the hot water zone valve was making a slight buzzing noise, but the lever was not moving. I looked at the wiring centre, and there was power at the grey wire to the valve (permanent live) and the brown (calling from the cylinder thermostat).

The valve was a Honeywell V4043H two-port zone valve and the head was jammed, but the spindle was free to turn after the head was removed. I replaced the motorised valve head and the hot water began heating correctly.

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.