If you are replacing your existing water heater, choosing the right size can help you minimize energy costs. With water heaters, bigger is not always better. Don’t move up to a larger size water heater unless you really need to.
Most residential water heaters hold 40 to 50 gallons although you can find water heaters a small as 30 gallons and as large as 100 gallons. Buying a water heater with a larger tank than you need will only increase your standby heat loss which is the energy consumed keeping the tank of water hot even though there is no immediate demand for hot water.
Consider whether you often ran out of water with your old water heater. If the answer is no, then you don’t need a large size tank in your new water heater. If you occasionally ran out of hot water, then you need to do a little more analysis. Is your old water heater full of sediment? If so, then the tank capacity was significantly reduced and a new water heater of the same size may provide all the hot water you need.
Did you run out of hot water while placing multiple demands on the water heater such as washing clothes or running the dishwasher while showering? By spacing out the demand for hot water, you may be able to continue using a smaller, more energy efficient water heater rather than moving up to a bigger one.
If running out of hot water was a frequent occurrence due to your family size and lifestyle, then moving up to a bigger tank would be a good choice.
