BoilerFaultCodesYour boiler has detected a problem with the sensor that monitors the temperature of the exhaust gases, causing the system to shut down for safety.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Flue negative thermistor coefficient (NTC) sensor error
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 control center. The most common reason is that the sensor itself has developed an electrical fault, though damaged wiring or a buildup of extreme heat in the flue system can also trigger the safety shutdown.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
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A boiler cover plan would cover faults like E28 — no call-out fees, no surprises.
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Could it be time for a new boiler?
If repair costs are adding up, a new energy-efficient boiler could be the smarter long-term choice.
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