Medium Lockout
E50 on Baxi 600 Combi (range)

Your boiler is having trouble measuring the temperature of your hot water, which usually means it won't be able to provide reliable hot water to your taps.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Book a service

This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.

Technical description

Domestic hot water (DHW) negative temperature coefficient (NTC) thermostat sensor fault (tank boiler) (s.c.) or DHW NTC sensor fault (tank boiler) (o.c.).

What causes this fault?

This fault occurs when the sensor responsible for monitoring your hot water temperature has failed or is giving an incorrect reading to the boiler's main control board. The most common reason is that the internal components of the sensor have worn out over time, or the electrical wiring connecting it to the system has developed a loose connection or a short circuit.

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

E20View →E28View →E110View →

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