How Much Gas Does a Hot Water Heater Use? Most gas hot water heaters use between 20-50 therms of gas per month. A therm is a unit of measurement for natural gas and is equivalent to 100,000 BTUs. So, if you have a gas hot water heater, it's likely using around 2,000-5,000 BTUs per hour.
Gas water heaters are much less expensive to operate long term. Overall, you'll likely spend less money running a gas water heater than using an electric water heater. Still, because the costs of both natural gas and electricity vary by region, you should compare the price of each before making your final decision.
Savings resulting from turning down your water heater temperature are based on reducing standby losses (heat lost from water heater into surrounding area). Set too high, or at 140ºF, your water heater can waste anywhere from $36 to $61 annually in standby heat losses.
Comparatively, energy-efficient gas water heaters have an EF of . 67 or higher, while energy-efficient electric water heaters have an EF of 2.00 or 2.20, depending on tank size. By meeting EF standards, they can be considered energy efficient. Many energy-efficient water heaters are gas-powered.
The disadvantages to a water heater fueled by gas are: Generally more expensive on the front-end cost. Requires more maintenance. Less efficient when it comes to heat loss.
Lifespan. The average lifespan of a tank gas water heater is about 8 to 12 years. Tankless electric water heaters have a longer lifespan and can last an average of 15 to 20 years or more.
Generally speaking, a gas water heater should not be turned off unless you are leaving the house for an extended period of time. Even then the better choice for gas water heaters is to just turn the temperature down. In fact, many water heaters have a “vacation” setting on the temperature control.
Efficiency. If you are comparing the efficiency of an electric water heater vs a gas unit, electric heaters are more efficient. Although gas hot water heaters are less expensive to run monthly due to the low cost of natural gas—a gas heater uses more energy to operate and releases waste into the environment.
What is the recommended temperature for your water tank? The best or optimal temperature for your hot water tank is 120 Fahrenheit or 48 Celsius. This is a temperature that is comfortable and sanitary, yet does not significantly increase your energy costs.
Tankless water heaters are more efficient than tank water heaters. Tankless water heaters last longer, so you'll save money by not replacing them. In general, gas water heaters are cheaper on a monthly basis than electric heaters.
While an electric water heater does heat water slower and more expensively than the gas models do, it heats the water more efficiently. The heating rods are submerged in the water in a sealed tank, so there is very little heat loss.
Switching from gas to electric
While not as common, it is possible to switch from a gas water heater to an electric one.
Pros and Cons of Gas Water Heaters
As for pros, gas water heaters are generally cheaper to operate, as gas is cheaper than electric. Gas water heaters can also heat more water power per hour than electric. And because they're not hooked up to electricity, your water heater can run during a power outage.
Standard Gas Tank: Most new water heaters have an Efficiency Factor (EF) of . 58-. 60. That means that 58-60% of the energy that is being used to heat your water is effectively converted into heat.
If you have several users and the hot water runs out, set the timer to run before and during bathtime. Let the timer go off afterwards. There is likely to be enough stored hot water to last all day. If your daily usage is less than the cylinder holds, just run it once a day for about half an hour.
While gas water heaters may cost less to operate, they can be more expensive to install. Electric water heaters could potentially have a higher operating cost, but installation likely costs less. Tankless water heaters, heat pump systems, and conventional storage tanks should all be taken into consideration, too.
Bowerman: Upgrading utilities can be fairly involved and will certainly require a professional's experience. If converting from gas to electric, not only will a plumber be needed, but the job will require an electrician, to upgrade the electrical panel and run an outlet for an electric water heater.
Average Lifespan Of A Hot Water Heater
With regular inspection, draining, and flushing, you can expect a gas water heater to last anywhere from 8-12 years and an electric water heater to last anywhere from 10-15 years.
If you're away during warmer months, placing the water heater in vacation mode is unnecessary, and the heater can just be powered off. This goes for both gas and electric water heaters. For gas, twist the thermostat dial to the OFF position. For electric models, turn off the water heater at the circuit breaker.
In most cases, it may not be necessary to turn off the water heater, but it also won't hurt, either. However, there are two reasons when you should turn off the unit to prevent too much pressure or heat from building up inside the tank: The tank is empty (or close to it) and won't be refilled for a long period of time.
Water Heater Maintenance Tips
Flush your water heater every six months or so. If you have harder water, or water that contains more minerals, you may want to flush it more often. If you leave town, change your water heater to its vacation setting. The pilot light will stay on, but the water will not be heated.
The tankless water heater is—you guessed it—tankless! Because there's no tank, it doesn't work off of capacity; it works off demand. A tankless water heater heats up water as you need it, and it brings hot water to your appliances quickly—and never runs out.
Advantages and Disadvantages
The initial cost of a tankless water heater is greater than that of a conventional storage water heater, but tankless water heaters will typically last longer and have lower operating and energy costs, which could offset their higher purchase price.
The U.S. Department of Energy reports a tankless water heater is 24% to 34% more energy-efficient than storage tank water heaters—as long as you use around 41 gallons per day. However, even if you double that amount, they are still 8% to 14% more efficient.