High Lockout
E20 on Baxi Platinum Heat

Your boiler's internal temperature sensor has stopped communicating correctly, preventing the system from heating your radiators.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description

Central heating NTC error

What causes this fault?

This fault occurs when the boiler's control board loses communication with the temperature sensor responsible for your radiators. This is typically caused by the internal sensor failing due to age or a loose electrical connection in the wiring harness that prevents the boiler from monitoring how hot the water is.

Engineer required

This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

E28View →E50View →E110View →

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