PP4 High
Your boiler has stopped working because one of its internal sensors is failing to monitor the temperature of the water returning to the unit.
Technical description: Return gas sensor failure
Typical repair cost: £120-190 (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 PP4 — no call-out fees, no surprises.
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Parts commonly replaced
- Return gas NTC sensor
- Wiring harness
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