F12 Medium
Your boiler's hot water sensor has stopped working, meaning the system cannot accurately monitor the temperature of the water coming out of your taps.
Technical description: DHW sensor error
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 F12 — 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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