How to Replace the Fan on a Glow-worm Ultimate 30c (UK)
Step-by-step UK guide to replacing the combustion fan on a Glow-worm Ultimate 30c. Part numbers, torques, commissioning.
Glow-worm
The part
Swap the combustion fan on Glow-worm Ultimate 30c when you get low-speed lockouts (F28/F29 Vaillant, EA Worcester, F1 Ideal) or bearing whine.
Isolate safely
Remove the case, disconnect the fan plug and Venturi. Note the fan's part number stamped on the motor housing.
Fit and commission
On Glow-worm Ultimate 30c the fan is torqued to 8–10 Nm — over-tightening cracks the composite plenum.
Recommission checklist
Refill the Glow-worm Ultimate 30c to 1.2 bar cold. Bleed high-point radiators and the internal AAV.
Run a full flue-gas analysis after 15 minutes. Log the reading against the OEM commissioning envelope in the Benchmark book.
Frequently asked questions
- Which speed sensor connector?
- The Hall-effect sensor on Glow-worm Ultimate 30c uses a 4-pin JST plug. Do not swap L1/L2.
- Do I need a new gasket?
- Always fit the OEM Viton gasket — the old one hardens and leaks flue gases into the case.
- Do I need to notify the manufacturer?
- Only if the Glow-worm Ultimate 30c is in warranty — Glow-worm require log of any part swap for labour claims.
Shop the spares
Browse boiler spares — 14,820 live parts.
View Boiler Spares