Low
S.30 on Glow-worm Sustain 12s

Your boiler is perfectly fine, but an external device like your wall thermostat or timer is currently telling it to stay 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 is blocking heating mode.

From this model's manual
Verified against the Glow Worm/Glow Worm Sustain 12s installation & service manual, page 33.
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 and ensure the set temperature is higher than the current room temperatureEnsure your timer or programmer is set to 'On' rather than 'Off' or 'Timed' if you are trying to get heat immediatelyReplace the batteries in your wireless room thermostat if it has a screen or light

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Related fault codes

S.31View →S.32View →

All 163 fault codes on the Sustain 12s

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

Connectiond.00d.01d.02d.04d.05d.06d.07d.08d.09d.10d.11d.13d.14d.15d.16d.17d.18d.19d.20d.21d.22d.23d.24d.25d.27d.28d.31d.33d.34d.35d.36d.39d.40d.41d.43d.45d.47d.50d.51d.58d.60d.61d.62d.64d.65d.66d.67d.68d.69d.70d.71d.73d.75d.77d.80d.81d.82d.83d.84d.85d.88d.90d.91d.93d.94d.95d.96d.128d.129F.00F.01F.10F.11F.13F.20F.22F.23F.24F.25F.27F.28F.29F.32F.33F.49F.61F.62F.63F.64F.65F.67F.68F.70F.71F.72F.73F.74F.75F.76F.77F.78F.83F.84F.85F.86F.87F.88F.89F.91F22P.01P.02P.03P.04P.05P.06P.07S.0S.01S.02S.03S.04S.05S.06S.07S.08S.10S.11S.13S.14S.15S.16S.17S.20S.21S.22S.23S.24S.25S.26S.27S.28S.31S.32S.33S.34S.39S.41S.42S.46S.53S.54S.76S.88S.91S.96S.97S.98S.99S.108S.109

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