E077 Medium
Your boiler has detected an issue with the sensor that monitors the water temperature in your main heating circuit, which may prevent your radiators from warming up correctly.
Technical description: Main zone water thermostat
Typical repair cost: £90-180 (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 E077 — no call-out fees, no surprises.
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Parts commonly replaced
- Main zone NTC thermistor
- Wiring harness
- Control PCB
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