E09 High
Your boiler has shut down because it has detected its internal temperature is getting too hot, usually caused by a blockage or a pump failure.
Technical description: Overheat sensor overheating
Typical repair cost: £120-350 (including labour)
DIY fix possible
Check that your radiator valves are fully open to allow water to flow.Check that your system pressure is between 1 and 1.5 bar on the gauge.Try resetting the boiler to see if the fault clears after the system has cooled down.
Protect yourself from future repair bills
A boiler cover plan would cover faults like E09 — no call-out fees, no surprises.
*Affiliate links — we may earn a commission at no extra cost to you. Prices shown are starting prices.
Parts commonly replaced
- Circulation pump
- Overheat thermostat
- Main heat exchanger
*Affiliate links — we may earn a commission at no extra cost to you.