E9 High
Your boiler has shut down because it has detected an unsafe build-up of heat or a lack of water circulation within the internal system.
Technical description: Safety temperature limiter in central heating (CH) flow has tripped
Typical repair cost: £120-250 (including labour)
DIY fix possible
Check if your boiler pressure gauge is below 1 bar and top it up if necessaryEnsure all radiator valves and the main isolation valves under the boiler are fully openGently press the 'Reset' button on the boiler control panel after the system has cooled down
Protect yourself from future repair bills
A boiler cover plan would cover faults like E9 — no call-out fees, no surprises.
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Parts commonly replaced
- Overheat Thermostat (Limit Switch)
- Circulation Pump
- Main Heat Exchanger (if blocked)
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