E125 High
Your boiler is struggling to move water around the system properly, which is causing it to shut down to prevent overheating.
Technical description: Primary circuit error circulation fault
Typical repair cost: £180-450 (including labour)
DIY fix possible
Check that all radiator valves (TRVs) are fully openEnsure your system pressure is between 1.0 and 1.5 bar on the gaugeTry resetting the boiler to see if the error clears
Protect yourself from future repair bills
A boiler cover plan would cover faults like E125 — no call-out fees, no surprises.
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Parts commonly replaced
- Circulation pump
- Diverter valve
- Main heat exchanger (flushing)
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