Low
S.30 on Vaillant Thermocompact

Your boiler is currently in standby mode because it has not received a request for heat from your wall thermostat or timer.

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.

Technical description

No heating demand from external controls

DIY fix possible

Check that your wall thermostat is set to a higher temperature than the current room temperature.Ensure your programmer or heating timer is switched to 'On' or 'Timed' mode.Verify that any smart heating apps or bridge devices are connected and have not lost their signal.

Find a Gas Safe engineer
Search the official register →

Related fault codes

S.31View →

Related guides you might find useful

Boiler won't turn on — 9-step checklist

Work through these before the call-out.

Read →

Is boiler cover worth it?

Break-even maths on monthly cover.

Read →

When to replace your boiler

7 signs repair isn't worth it anymore.

Read →