BoilerFaultCodesYour boiler is having trouble measuring the temperature of your hot water, which usually means it cannot heat it safely or effectively.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Hot water sensor defective.
What causes this fault?
This fault occurs when the internal sensor responsible for monitoring the temperature of your hot water fails to send a reliable signal to the boiler's control board. The most common reason is that the sensor has physically degraded over time or developed an electrical short, meaning the boiler can no longer verify if the water is at a safe temperature. In some cases, it may also be caused by damaged or corroded wiring connecting the sensor to the main computer.
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 A7 — 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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