164 High
Your boiler has detected a problem with the sensor or switch that monitors water movement, preventing the system from heating up properly.
Technical description: Pressure Sensor Error (UK) – Heating flow switch error (Ireland)
Typical repair cost: £120-240 (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 164 — no call-out fees, no surprises.
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Parts commonly replaced
- Water pressure sensor
- Flow switch
- Wiring harness
- Main PCB
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