Low
d.09 on Glow-worm MicraCom

Your boiler is simply displaying the temperature it has been told to reach by your smart thermostat or heating controller.

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

Target heating flow temperature that is set on the eBUS room thermostat

Shared across the MicraCom range
This code is shared by the boilers in this range, which use the same control board. It may not be printed in this exact variant’s manual.
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 wall-mounted room thermostat or heating appObserve if the display changes when you adjust the temperature settingsNo action is needed as this is a normal status message, not a fault

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Related fault codes

d.00View →d.01View →

All 138 fault codes on the MicraCom

Seeing a different code? Every code this model can display, in one place.

d.00d.01d.02d.05d.06d.08d.10d.11d.13d.14d.15d.16d.17d.18d.20d.21d.22d.23d.27d.28d.33d.34d.35d.36d.39d.40d.41d.43d.45d.47d.50d.51d.58d.60d.61d.64d.65d.67d.68d.69d.71d.80d.81d.82d.83d.85d.88d.90d.91d.93d.94d.96d.149d.165d.191d.192F.00F.01F.10F.11F.13F.20F.22F.23F.24F.25F.27F.28F.29F.32F.33F.46F.49F.61F.62F.63F.64F.65F.67F.68F.70F.71F.72F.73F.74F.75F.76F.77F.78F.83F.84F.85F.86F.87F.88F.89F.97S.00S.01S.02S.03S.04S.05S.06S.07S.08S.10S.11S.13S.14S.15S.16S.17S.20S.21S.23S.24S.25S.26S.27S.28S.30S.31S.32S.34S.39S.41S.42S.46S.53S.54S.58S.76S.88S.91S.96S.98

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