E.01 – .02 High
Your boiler has detected that the water coming back from your radiators is hotter than the water leaving the boiler, which usually means water is flowing in the wrong direction or a sensor has developed a fault.
Technical description: Temperature measured by return sensor greater than flow sensor.
Typical repair cost: £120-£280 (including labour)
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Protect yourself from future repair bills
A boiler cover plan would cover faults like E.01 – .02 — no call-out fees, no surprises.
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Parts commonly replaced
- Flow/Return NTC thermistor
- Water pump
- Main PCB
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