Low
S.30 on Glow-worm MicraCom

Your boiler is currently prevented from turning on the heating because your external room thermostat is telling it that the house is already warm enough or has been switched off.

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

Room thermostat blocks heating mode.

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

Locate your wall-mounted room thermostat or smart controller.Increase the target temperature on the thermostat to be higher than the current room temperature.Check if the thermostat is set to an 'Off' or 'Summer' mode and switch it to 'Heating' or 'Winter' mode.

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Related fault codes

S.31View →

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.09d.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.31S.32S.34S.39S.41S.42S.46S.53S.54S.58S.76S.88S.91S.96S.98

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