E03 High
Your boiler has become too hot and has shut itself down as a safety precaution to prevent damage.
Technical description: Boiler overheat – check that any valves to the heating circuit have not been shut down, no air in the system and that the water pressure is correct
Typical repair cost: £100-£350 (including labour)
DIY fix possible
Check that the boiler pressure is between 1.0 and 1.5 bar on the gauge.Ensure all radiator valves and internal isolation valves are fully open.Bleed your radiators to remove any trapped air pockets from the system.
Protect yourself from future repair bills
A boiler cover plan would cover faults like E03 — no call-out fees, no surprises.
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Parts commonly replaced
- Circulation Pump
- Overheat Thermostat
- Thermistor (NTC Sensor)
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