BoilerFaultCodesYour boiler has detected a fault with the sensor that monitors the temperature of the water leaving the unit, preventing it from heating your home safely.
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 (CH) water flow negative thermistor coefficient (NTC) sensor defective check CH flow NTC sensor and connection leads.
What causes this fault?
This fault occurs when the boiler's internal computer loses communication with the sensor that measures the heat of the water heading to your radiators. The most common reason is that the sensor has physically failed or developed a short circuit, though it can also be caused by loose or damaged wiring connecting the sensor to the main control board.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
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A boiler cover plan would cover faults like E2 — no call-out fees, no surprises.
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