Question: how long does it take for a 50 gallon water heater to drain?
Answer: Aside from labor time, the tank size itself is what dictates how long it takes to drain your water heater. If you have a 50 gallon tank and the pressure of your hose allows the water to flow at 10 gallons per minute (GPM), then you can expect the tank to fully drain in about 5 minutes[3].