Low
D.78 on Vaillant Combi Compact 242EB

Your boiler is limiting the temperature used to heat your hot water, which usually means it is trying to prevent internal overheating or scale build-up.

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

Limitation of cylinder charging temperature in c

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

D.77View →F.20View →F.24View →

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