Low
d.20 on Vaillant Home System

Your boiler is currently set to its maximum limit for how hot your water is allowed to get.

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.

What the manual says

Manufacturer manual

Maximum hot water set target temperature: 50 to 60 ℃

From this model's manual
Verified against the Vaillant Home System installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

DIY fix possible

Press the 'i' and '+' buttons simultaneously to enter the diagnostic menuUse the '+' button to scroll to code d.20Press the 'i' button to view the current valueAdjust the temperature using the '+' or '-' buttons then hold 'i' to save

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Related fault codes

d.00View →d.01View →d.21View →

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