E125 High
Your boiler is struggling to move hot water around the system, which is usually caused by a blockage or a pump issue that is preventing the unit from cooling itself down.
Technical description: Circulation error
Typical repair cost: £150-350 (including labour)
DIY fix possible
Check that all radiator valves are fully openEnsure the boiler pressure is between 1.0 and 1.5 bar on the gaugeGently bleed air from your radiators using a radiator key
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
- Plate heat exchanger
- Main heat exchanger
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