Low
d.20 on Vaillant ecoTEC sustain

This code is not actually an error; it is a status message showing the current setting for your maximum hot water temperature.

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

Maximum hot water set target temperature: 50 to 60 ℃

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.21View →d.22View →

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