BoilerFaultCodesYour boiler is having trouble measuring the temperature of your hot water, which means it cannot safely heat water for your taps.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Domestic Hot Water thermistor fault.
What causes this fault?
This fault occurs when the internal sensor responsible for monitoring your hot water temperature fails or sends an unreadable signal to the control board. The most common reason is that the sensor has suffered electrical failure due to age, or the wiring connecting it to the main system has become loose or damaged.
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.
Gas Safe Register →Protect yourself from future repair bills
A boiler cover plan would cover faults like F7 — no call-out fees, no surprises.
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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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