A7 High
Your boiler's hot water sensor has failed or has a broken connection, meaning you likely won't have any hot water.
Technical description: The hot water negative thermistor coefficient (NTC) sensor is defective – the hot water sensor or connecting leads need checking.
Typical repair cost: £90-160 (including labour)
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Protect yourself from future repair bills
A boiler cover plan would cover faults like A7 — no call-out fees, no surprises.
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Parts commonly replaced
- Domestic Hot Water (DHW) NTC Sensor
- Sensor Wiring Harness
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