Worcester Bosch Diverter Valve Passing to Heating Circuit

Radiators get hot when only hot water is demanded on a combi boiler.

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

Worn diverter valve seals, Debris preventing full closure, Faulty diverter actuator not returning fully

Safety first: Isolate power and allow system to cool before working on the diverter valve.

Engineer actions:

Inspect the diverter valve for correct movement between DHW and CH positions.
Replace the diverter valve cartridge or complete assembly if it is passing water to the heating circuit when in DHW mode.
Check the actuator for correct operation and replace if sluggish or sticking.
Flush the system to remove debris that may cause future sticking.

Hard 4/5

Diverter Valve Assembly

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