E125 High
Your boiler has detected that hot water isn't moving through the system properly, which is causing it to shut down to prevent overheating.
Technical description: Primary water circulation error
Typical repair cost: £150-£350 (including labour)
DIY fix possible
Check that your system pressure is between 1 and 1.5 bar on the pressure gauge.Ensure all radiator valves and any isolation valves under the boiler are fully open.Listen for air trapped in the system and bleed your radiators if necessary.
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
- Water Pressure Sensor
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