How long to heat 400 gallons of water 30 degrees with 5500 watt heater?

To heat 400 gallons of water by 30 degrees Fahrenheit using a 5500-watt heater, you can use the formula: time (in hours) = (volume in gallons × temperature increase in °F × 8.34) / heater wattage. Plugging in the values: time = (400 × 30 × 8.34) / 5500, which calculates to approximately 91.5 minutes. Therefore, it would take about 1.5 hours to achieve the desired temperature increase.