BoilerFaultCodesWhat the manual says
Manufacturer manualFlue NTC Fault
From this model's manual
Verified against the Potterton Promax System He Plus installation & service manual, page 64.
What causes this fault?
This fault occurs when the sensor responsible for monitoring the temperature of the exhaust gases sends an incorrect or missing signal to the boiler's internal computer. The most common reason is that the sensor itself has worn out or developed a short circuit, though loose or damaged wiring between the sensor and the main control board can also trigger the shutdown.
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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