Low
S.00 on Vaillant Combi Compact 242EB

Your boiler is currently on standby because it hasn't received a signal from your thermostat to turn the heating on.

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

Heating mode error – no heat demand

DIY fix possible

Check that your room thermostat is turned up higher than the current room temperatureEnsure your heating programmer or timer is set to an 'ON' periodReplace the batteries in your wireless thermostat if the screen is blank

Find a Gas Safe engineer
Search the official register →

Related fault codes

S.02View →S.07View →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 →