F08 – A08 High
Your boiler has sensed that parts of the internal system have become too hot, causing it to shut down automatically to prevent damage.
Technical description: Overtemperature protection intervention
Typical repair cost: £120-350 (including labour)
DIY fix possible
Check that your radiator valves are open to allow water to circulate.Ensure there is enough water pressure in the system (typically 1.0 to 1.5 bar).Press the 'Reset' button on the control panel to see if the fault clears.
Protect yourself from future repair bills
A boiler cover plan would cover faults like F08 – A08 — no call-out fees, no surprises.
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Parts commonly replaced
- Circulation Pump
- Heat Exchanger (Cleaning/Descaling)
- NTC Temperature Sensor
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