E109 High
Your boiler has detected that water is not circulating correctly before the burner lights, which usually means there is a blockage or a pump issue.
Technical description: Pre-circulation fault
Typical repair cost: £180-350 (including labour)
DIY fix possible
Ensure your radiator valves are open to allow water flowCheck that the boiler pressure is between 1 and 1.5 bar on the gaugeRestart the boiler by pressing the reset button for five seconds
Protect yourself from future repair bills
A boiler cover plan would cover faults like E109 — no call-out fees, no surprises.
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Parts commonly replaced
- Circulation Pump
- Main Heat Exchanger (Descaling)
- Flow Temperature Sensor
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