BoilerFaultCodesYour boiler is having trouble measuring the temperature of your hot water, which usually means it cannot heat water 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: DHW Thermistor Fault
What causes this fault?
This fault occurs when the sensor responsible for monitoring your hot water temperature has failed or is sending incorrect readings to the main control board. The most common reason is that the internal components of the sensor have degraded over time, though it can also be caused by loose or damaged electrical wiring. Because the boiler cannot accurately tell how hot the water is, it shuts down as a safety precaution to prevent overheating.
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 4.14 — 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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