Boiler displays E11 and locks out during hot water demand.

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 DHW flow sensor or turbine, Blocked DHW inlet filter, Faulty DHW flow switch, Limescale in the DHW flow path.

Safety first: Turn off the power and close the cold water isolation valve to the boiler before removing any DHW components.

Check DHW flow: Open a hot tap fully. If the boiler does not recognise flow (no flame symbol, no start), the DHW flow sensor may be stuck.
Clean inlet filter (engineer): Many Remeha combi boilers have a cold inlet filter that can become blocked. A competent engineer should isolate the boiler, remove, and clean this filter.
Engineer tasks: Inspect and clean or replace the DHW flow sensor/turbine, descale the DHW side if heavily scaled, and verify correct wiring to the PCB.

Hard 4/5

DHW Flow Sensor

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