UK trade guideBoiler Spares 5 min readUpdated 9 July 2026

How to Replace a Baxi Fan Assembly (UK)

Fit Baxi 720873101 fan on 800/EcoBlue/Duo-tec ranges. Wiring, gasket and PCB reset.

Baxi

Fault codes

E133 (flame loss on ignition) and E168 (fan speed out of range) both point to fan. Check PWM signal at 5 V before fitting.

Fit

Isolate. Remove case, disconnect PWM and 230 V plugs. Undo three M6 flange bolts. Fit new gasket (never re-use). Torque 6 Nm cross-pattern.

Frequently asked questions

Does Baxi need PCB reset after fan swap?
No — auto-detected on first ignition attempt.
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