Dimplex Motorised Valve / Hot Water Control Fault

Boiler does not fire for hot water unless heating is also on (on system/heat-only setups)

Safety Warning

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Possible Causes

Stuck or failed hot water motorised valve, Faulty cylinder thermostat not calling for heat, Wiring fault between cylinder stat, valve, and Dimplex boiler, Failed end switch in motorised valve

How to Fix / Troubleshooting

Safety first: Isolate power before working on motorised valves or wiring.

User checks:

Programmer settings: Ensure hot water channel is set to ON or timed correctly.
Cylinder stat: Turn the cylinder thermostat up and listen for a click indicating it is calling for heat.

Professional actions:

Test and replace the hot water motorised valve if stuck or if the end switch has failed.
Verify wiring between the cylinder stat, valve, and Dimplex boiler.

Repair Difficulty

Medium 3/5

Required Part

Hot water motorised zone valve

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