Low Warning
S.16 on Glow-worm Ultracom 24cx 30cx

Your boiler's fan is running longer than necessary to clear out exhaust gases, which may temporarily stall the start-up process.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

Technical description

fan overrun

What causes this fault?

This fault occurs when the boiler's internal computer detects that the fan is spinning for too long or at an unexpected time during the ignition sequence. The most common reason is a communication error between the fan and the main control board, or the fan itself beginning to wear out and failing to stop when instructed.

DIY fix possible

Check for any visible obstructions to the external flue terminalMonitor the boiler to see if it clears the state and proceeds to ignitionPerform a reset if the boiler becomes stuck in this status code

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