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Plumbing

Boiler doesn't respond to hot water demand until central heating is turned on

Anonymous user 9 September 2019 - 7.26 AM

I have a Worscester Greenstar System Boiler and Drayton LP522Si Programmer. All has been fine till this weekend. When hot water is demanded by the controller, I can see the Drayton Motorised Valve turning to let the water through the valve but then nothing happens after that. The boiler doesnt fire up to heat the water for the tank. When I then turn the central heating on, CH Motorised Valve turns the valve then both start working. Both of the motorised valves seem to be working fine. Not sure what could be causing the problem. Want to get an idea of what could be wrong so I know if someone I call out is advising me correctly. If anyone could suggest, would greatly appreciate it. Edit: Unplugged the new actuator I replaced for heating and plugged it into the valve for hot water and voila! Ordered a new one for hot water aswell. Hopefully that'll be the end of it. Thanks for your responses.

4 answers from MyBuilder tradespeople

Anonymous user

I would say 100% hot water motorised valve. Not making contact with the switch inside.

Answered

9 September 2019

Anonymous user

Most likely the motorised valve for hot water. Quickest cheapest option would be to change the Synchron motor. But a good plumber would check to see if the valve is stiff. Otherwise replace the head/body. If the system is drained down, add a corrosion inhibitor when filling back up.

Answered

11 September 2019

Anonymous user

motorised valve faulty, replace, some time lime scale affect, the good working order,

Answered

10 September 2019

BS Heating

Rating: 5 out of 5552 reviews

Slough

Faulty zone valve

Answered

11 September 2019