Boiler displays E10 and will not start central heating.

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

Seized circulation pump, Air lock in the pump or system, Closed isolation valves on flow/return, Faulty flow switch or flow sensor.

Safety first: Isolate the power supply before touching the pump or opening any bleed points.

Check isolation valves: Ensure the flow and return isolation valves under the boiler are fully open.
Bleed the pump (if fitted with bleed screw): With the power off, carefully loosen the pump vent screw to release trapped air, then retighten it. Have a cloth ready for any small water drips.
Listen for pump operation: Restore power and call for heat. The pump should hum and vibrate slightly. If silent, it may be seized or not powered.
Engineer tasks: Test the pump electrically, free or replace the pump, and check the flow switch or flow sensor for correct operation.

Hard 4/5

Primary Circulation Pump

Check Price on Amazon

We may earn a commission from links on this page.