H.01 – .05 High
Your boiler has detected that the water is heating up too quickly or isn't circulating properly through the system.
Technical description: Difference between the flow and return temperature is too high, sensor error or insufficient 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 gaugeEnsure all radiator valves are fully openCheck for any visible leaks around the boiler or pipeworkRestart the boiler using the reset button
Protect yourself from future repair bills
A boiler cover plan would cover faults like H.01 – .05 — no call-out fees, no surprises.
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Parts commonly replaced
- Circulation Pump
- Flow/Return Temperature Sensor (NTC)
- Central Heating Filter
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