... long to heat the water in whole tankFit for large powerUnderside heaterHeater put under bottom of water ... uses.Heating water for shower, ducking bath, footbath, washing hand, vegetable and dish. PTC water heater for drink warmer and boiler ... as a heating element, it fits for high safety, slap-up product.For getting higher power, let water ... voltage twice or decrease of 1/2, for the same PTC heater.