Low
D.5 on Vaillant Combi Compact 242EB

Your boiler is currently showing you what temperature it is aiming to reach rather than a specific error or mechanical failure.

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

Set value of flow temperature or target value of return

DIY fix possible

Check that your external room thermostat or smart controls are turned up to call for heatObserve if the display changes to a live temperature reading after a few momentsWait for the boiler to complete its current heating cycle as this is often an information code rather than a lockout

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Related fault codes

D.0View →D.1View →D.2View →

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