Low
S.31 on Glow-worm Ultimate3 System

Your boiler is currently in standby mode because it has not been asked to provide any heating or hot water, and it is waiting for a signal from your thermostat.

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.

What the manual says

Manufacturer manual

No heating demand: Summer mode, eBUS controller, waiting period

From this model's manual
Verified against the Glow Worm Ultimate3 System installation & service manual, page 43.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

DIY fix possible

Check your thermostat or smart controller settings to ensure it is set to 'On' or 'Winter' modeIncrease the target temperature on your room thermostat to see if the boiler initiates a firing sequenceIf the boiler remains in this state despite wanting heat, check your external controller's battery or connection

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