Low
d.43 on Vaillant Home System

Your boiler is currently set to a low-temperature efficiency mode which may prevent your radiators from getting as hot as you expect during very cold weather.

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

Heating curve: 0.2 to 4

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

Navigate to the installer menu or settings on your thermostat control.Locate the 'Heating Curve' or 'd.43' setting.Gradually increase the number (e.g., from 1.2 to 1.5) if your home is not reaching the desired temperature.

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d.45View →d.47View →

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