Worcester Bosch Diverter Valve Stuck in Heating Position

No hot water but central heating works normally on a Worcester Bosch combi boiler.

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

Jammed diverter valve cartridge, Failed diverter motor/actuator, Debris or scale in diverter body

How to Fix / Troubleshooting

Safety first: Turn off power and isolate cold water supply to the boiler. Allow the appliance to cool.

User checks:

Confirm that the hot water demand light or symbol appears on the boiler when a tap is opened. If not, the issue may be with the flow sensor rather than the diverter.

Engineer actions:

Remove the diverter valve motor/actuator and check if the valve spindle moves freely; if stiff, replace the diverter cartridge or complete valve.
Test the actuator for correct movement when hot water is demanded; replace if not operating.
Flush the system and fit a magnetic filter to reduce future debris build-up.

Repair Difficulty

Hard 4/5

Required Part

Diverter Valve Assembly

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