Glow-worm Fan Assembly Flexicom GLOWWORM0020020734

The Glow-worm 0020020734 is a fan assembly used on Flexicom boilers. It sits in the combustion circuit and provides the forced draught that draws air into the burner and drives the products of combustion out through the flue terminal. Because the boiler's safety interlock depends on proven fan operation, a failing assembly usually shows up as a lockout rather than a gradual loss of performance.

The unit is supplied as a complete assembly, so the motor, housing and impeller are replaced together rather than rebuilt on site.

• The boiler locks out on start-up or during a run cycle with a fan or air-pressure related fault code.
• A whine, rumble or grinding noise comes from the fan housing when the boiler fires.
• The fan runs intermittently, or the boiler drops out mid-cycle once the burner has lit.
• The impeller is stiff to turn by hand, or does not spin freely when the boiler calls for heat.
• Soot, condensate staining or debris is visible around the fan mounting or flue connection.

• Check the boiler's model and GC number against the compatibility list, as Flexicom variants use different assemblies.
• Confirm the number on the existing fan matches 0020020734 before ordering.
• Inspect the fan mounting gasket and flue seals while the boiler is open, and renew them if they are perished.