Low
D.17 on Vaillant Combi Compact 242EB

Your boiler has detected that the water returning from your radiators is too hot, causing the system to automatically reduce its power output to protect itself.

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 glow return regulation

DIY fix possible

Ensure all radiator valves (TRVs) are fully openCheck that there are no obstructions around the boiler ventsMonitor if the boiler resumes normal operation after cooling down

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Related fault codes

D.18View →F.23View →

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