Low
d.02 on Vaillant ecoTEC plus aquaPLUS

Your boiler is temporarily pausing its burner to prevent it from switching on and off too frequently, which helps protect the components from wearing out.

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 burner anti cycling period at 20 °C flow temperature

From this model's manual
Verified against the Vaillant Ecotec Plus Aquaplus 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

Wait 15-30 minutes for the countdown to end and the boiler to restart automaticallyEnsure all radiator valves are fully open to allow heat to dissipateCheck that the thermostat is calling for heat

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