E20 High
Your boiler's internal temperature sensor has developed a fault, meaning the system cannot correctly monitor the heat of your radiators and has shut down as a precaution.
Technical description: Central heating negative temperature coefficient (NTC) thermostat fault.
Typical repair cost: £90-160 (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 E20 — no call-out fees, no surprises.
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Parts commonly replaced
- Central heating NTC sensor
- Wiring harness connectors
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