Why should I reset my Philips air purifier/humidifier after replacing a filter?

The action of reset is to activate counting system for concerned filter(s). In addition, the appliance is equipped with HealthyAirProtect Alert, it warns you when filter needs to be cleaned (filter 1 only) and replaced. If you do not reset the appliance after replacing a new filter, the appliance will alert you to replace a filter far too earlier than actual life span. The HealthyAirProtect Alert and HealthyAirProtect Lock features with the appliance ensuring filters are always at optimal condition so that you can breathe healthy air always.