Baxi Wiring Harness Fan 720774201

The Baxi 720774201 is a fan wiring harness — the electrical loom that connects the combustion fan to the appliance's control circuitry. It is manufactured by Baxi for use across the Duo-Tec Combi and Megaflo 2 System ranges, including the LPG and natural gas variants of the Duo-Tec 2 Combi.

The harness carries the supply and signal connections the fan needs to run at the speed demanded by the board, so a damaged or degraded loom can interrupt fan operation and trigger a lockout or fault code.

• The fan fails to start, or runs intermittently, with the appliance locking out shortly after ignition demand.
• Fault codes relating to fan speed or fan feedback appear on the display.
• The loom shows heat damage, brittle or cracked insulation, or exposed conductor near the fan connector.
• Connector terminals are corroded, loose or have pulled away from the plug body.
• Continuity testing across the harness shows an open circuit or intermittent reading when the loom is flexed.

• This part is fitted to a gas appliance; installation must be carried out by a Gas Safe registered engineer.
• Check the appliance GC number and model against the compatibility list before ordering, as the same appliance family uses different looms across variants.
• The alternative part number 1119758 may be listed on older documentation or on the existing component.
• Confirm the appliance serial number and model variant, particularly where an LPG or natural gas version of the same output is in use.