Voltas Vertis Plus Split Ac User Manual -

The unit is equipped with high-capacity anti-dust filters. For optimal performance, these should be cleaned regularly to prevent dust buildup.

An E4 code typically indicates the unit has entered "defrost mode" because it became too cold, which may sometimes be caused by a faulty temperature sensor. Voltas Vertis Plus Split Ac User Manual

Standard cooling mode. You can manually adjust the temperature, typically between 16°C and 30°C, using the "+" and "-" buttons. The unit is equipped with high-capacity anti-dust filters