Low
d.09 on Glow-worm Sustain 12s

This code is not a fault; it is simply showing the current temperature setting that your wall-mounted thermostat is requesting from your boiler.

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

Heating flow set target temperature that is set on the eBUS room thermostat

From this model's manual
Verified against the Glow Worm Sustain 12s installation & service manual, page 29.
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 room thermostat to see what temperature you have setAdjust the thermostat dial or digital setting if you feel the house is too hot or coldMonitor the boiler display to ensure it returns to standard operation

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