E109 High
Your boiler is struggling to move water around the system effectively, which is causing it to shut down to prevent overheating.
Technical description: Poor circulation
Typical repair cost: £120-280 (including labour)
DIY fix possible
Check that the boiler pressure is between 1 and 1.5 bar on the pressure gauge.Ensure all radiator valves and internal stop taps are fully open.Gently bleed your radiators to remove any trapped air pockets.
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
- Central heating pump
- Magnetic system filter
- Main heat exchanger
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