How to Accurately Estimate Water Heater Energy Costs

How to Accurately Estimate Water Heater Energy Costs

Some might think that being frugal simply means buying whatever is cheapest, but when it comes to replacing water heaters, saving now may actually cost you more money in the long run. The average water heater lasts 13 years, and throughout those years a single unit uses up a lot of energy. There are a lot of choices to make when choosing a new heater, including whether to choose gas or electric, but you should estimate the energy costs of each individual water heater before making a decision.

Base Model

Before looking at new models, you will need a base model to compare them to. If you have the information for your existing water heater, you could use that for comparisons, but most people don’t have the information. Fortunately, the US Department of Energy has established a minimum standard for gas and electric heaters, which is an energy factor of .59 and .86 respectively. If you purchase the cheapest water heater you can find, its energy factor will be very close to these minimums.

Energy Factor

When looking at new water heater models, you want to find the energy factor. The energy factor is a number that describes how efficiently the water heater operates. The higher above the minimum this energy factor is, the less energy it will use. However, this can only be used to compare gas-to-gas and electric-to-electric heaters because of differing energy costs.

Estimated Water Usage

Estimating your hot water usage is important because the more hot water you use, the more money you could save by switching to a more efficient unit. The average shower uses 10 gallons of water, a washing machine cycle uses seven gallons, and a dishwasher uses six gallons, but this all depends on how efficient your fixtures and appliances are. If you feel that your hot water usage is pretty normal, you probably use about what the average daily household uses, which is 64 gallons a day.

Energy Costs

Electric water heaters are substantially more energy efficient than gas water heaters, but because electricity costs are usually much higher than natural gas prices, gas is still usually the cheaper option. You can check your local gas and electrical supply companies for prices online or in your most recent bills.


Now that you have all of these numbers and figures, it’s time to use them. The Federal Energy Management Program has an interactive energy cost calculator online that will compare costs for you. Also, most water heaters come with yellow labels attached that provide estimated yearly energy costs and other info. After 13 years of use, those energy costs will be several thousands of dollars, so before having Roto-Rooter in Sarasota install your new water heater, calculate how much you’ll really be paying.

Copyright © 2006-2017, Roto-Rooter Group, Inc. All rights reserved.
All services may not be available from all locations.


We use your ZIP code to give you local services and offers.