BoilerFaultCodes.com
F19 High Lockout

Your boiler has lost connection with a temperature sensor, meaning it cannot safely monitor the heat of the water going to your radiators.

Call an engineer soon

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

Technical description: Central heating NTC unplugged

What causes this fault?

This fault occurs when the boiler's internal computer can no longer detect a signal from the temperature sensors located on the main pipes. The most common reason is that the sensor has developed a hardware failure or the electrical wiring connecting it to the main control board has become loose or damaged. Without this connection, the boiler shuts down as a safety precaution because it cannot tell if the water is becoming dangerously hot.

Typical repair cost £90-160 (including labour)

Engineer required

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

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