Flow/Return reversed High
Your boiler has detected that heat is moving through the pipes in the opposite direction than expected, usually caused by a sensory error.
Technical description: Check if flow thermistor is correctly clipped to pipe. Replace flow thermistor.
Typical repair cost: £90-180 (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 Flow/Return reversed — no call-out fees, no surprises.
*Affiliate links — we may earn a commission at no extra cost to you. Prices shown are starting prices.
Parts commonly replaced
- Flow thermistor
- Return thermistor
- Wiring harness
*Affiliate links — we may earn a commission at no extra cost to you.