A plug has to be unscrewed from the bottom of the holding tanki have another make it has no plug to unscrew just fill it from the top quick and simple its done a great job of humidifying my condo in the winter time

It puts out a lot of moisture which is goodit is a awkward and a pain to fill it up

My only complaint is the whole unit needs to be brought to a sink to refill it without spillage

It hasnt gotten unduly hot or acted strange when the water level has run low and leaving it running overnight has not broken it