BoilerFaultCodesYour boiler's temperature sensor is sending incorrect information to the control board, preventing the system from heating up safely.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Flow thermistor fault
What causes this fault?
This fault occurs when the internal sensor responsible for monitoring the temperature of the water leaving the boiler fails or provides an illogical reading. The most common reason is that the sensor has suffered electrical degradation over time or has developed a loose connection, meaning the control board can no longer safely regulate the heat.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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A boiler cover plan would cover faults like E35 — 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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