BoilerFaultCodesThe boiler's internal thermometer is sending an incorrect signal to the control board, preventing the system from heating your water correctly.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Flow sensor error – sensor damaged
What causes this fault?
This fault occurs when the boiler's control board loses communication with the temperature sensor or receives a reading that is outside of its normal operating range. The most common reason is that the internal thermistor has chemically degraded over time, but it can also be caused by loose or corroded electrical connections between the sensor and the main board.
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 A42 — no call-out fees, no surprises.
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Ferroli Modena HE is discontinued — time for a new one?
Parts for discontinued models can be hard to find and expensive. A new A-rated boiler could save you money on both repairs and energy bills.
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