Guide to Gas Water Heaters

By Beth Krietsch | Advertiser Disclosure

When the cool fall weather sets in, staying warm and comfortable becomes a priority for most. To avoid stepping into a cold shower in the depths of winter, ensure your water heater is functioning properly. Here’s our guide to owning, maintaining, repairing, and replacing a residential water heater. 

Gas water heater maintenance and repairs

A water heater is one of the most used items in your house—you’ll likely use it more than your heating system or air conditioning. Because of this, regular maintenance is recommended. Protect your investment by maintaining your gas water heater to prolong its life and save you money.

The U.S. Department of Energy recommends checking the pressure valve and temperature gauge on your gas water heater twice a year and flushing one quart of water from tank-based heaters every three months. 

Turn off the water heater the night before you plan to service it before you complete any of these maintenance steps:

  1. Check the valvesTest for temperature and pressure before you begin any other maintenance on your gas water heater. Most experts recommend setting the pressure reducing valve at 50–60 psi to protect you and your appliance. A dripping temperature typically means that the water pressure is set too high. 
  2. Inspect for leaks—To spot leaks, mix one cup of wrist-tolerable-temperature water with 5–10 drops of dish liquid. Apply the solution to the pipes and joints of your water heater. If you see any bubbles, this means that your water heater has leaks. This would warrant calling a professional.
  3. Drain and flush the tank—Close the cold water supply valve and connect a small piece of hose to the drain valve to properly drain the tank into the correct location. Open the temperature and pressure relief valves. Drain two to three gallons of water from the tank—if the water is milky, drain the entire tank. Open a hot water faucet elsewhere in your house and run it for at least three minutes before returning to your water heater and clearing any excess air out of the system. For more detailed steps, see our guide on flushing your water heater.
  4. Check the anode rod—This part helps reduce corrosion and extends the life of the water heater. To check the anode rod, you’ll need a 1116inch socket and impact wrench. Ensure the cold water supply valve is turned off and the pressure in the tank is relieved. Locate the anode rod and replace it if it’s significantly depleted. You should check the anode rod at least once every three years—annually if your water heater uses water softener.

Types of gas water heaters

It costs money to heat water for your house—an estimated 18% of household energy use comes from your water heater. The age and type of water heater in your house has a dramatic impact on the cost of that energy use. Water heaters typically last for 8–15 years, but proper maintenance will help increase the longevity of your water heater.

There are multiple types of water heaters—standard, high efficiency, solar, tankless, and point-of-use. Most tank water heaters use either gas or electricity to heat water, so the type of energy available in your home may be a factor in deciding which water heater to purchase.

Standard storage tank water heaters

These are the most popular type of water heater, typically because this is what’s already installed in your home. Standard water heaters, also known as natural gas water heaters, use a gas flame or an electric heating element to heat water and store that hot water in a tank for future use in the home.

Gas water heaters are typically cheaper to operate than electric water heaters, though the upfront costs are a bit higher. Expect to pay $300–$600 for a gas water heater and $250–$500 for an electric water heater, along with $700–$2,000 for installation.

High efficiency storage tank water heaters

These are the most energy-efficient storage tank water heaters available on the market. You’ll do best to find an Energy Star-certified high efficiency gas water heater, as they’ll use 10%–20% less energy than standard gas water heaters. You can expect to pay $620–$1,500 for the system, plus $700–$2,000 for installation.

A gas condensing standard storage tank water heater works by reusing hot gas rather than deploying it out of the flue. This makes them more efficient with projected annual savings of $100–$140, for a total savings of nearly $3,000 throughout the lifespan of the water heater.

Solar water tank heaters

Best suited for mild or hot climates, solar water heaters have two components—a thermal collector located on the roof or in the yard and a storage tank with a backup source of hot water, typically a smaller capacity gas or electric water heater.

Solar installations will cost $8,000–$10,000 but will function much longer than standard gas or electric heaters. Still, at that price point, it would take more than 30 years of energy savings to pay back the upfront costs.

Point-of-use water heaters

The main benefit of point-of-use water heaters is to reduce the amount of water wasted while waiting for the tap to run hot. These are installed at the site they’ll be used—sinks, bathtubs, or showers—and are typically electric rather than gas-powered. While water waste may be reduced, the energy used powering the device will run up the utility bill.

Tankless water heaters

Instead of storing heated water for future use, tankless water heaters work on demand, using coils to heat the water when a tap or faucet is opened in the system. Tankless heaters cost between $400 and $1,500 depending on the power source—gas is more expensive than electric—yet have been found to be more efficient than heaters with a tank.

These water heaters are ideal for individuals or families that use only one source of hot water at a time—tankless heaters will not work for families that use multiple water sources simultaneously. 

How to find the right gas water heater

When replacing a water heater, it may seem easier to stick with the same type or model of water heater currently installed in your home. Just because the storage tank capacity is the same size doesn’t mean that a new model water heater will fit the space the exact same way—technology has changed in the last 8–15 years since your current model was installed.

Water heaters come in a variety of sizes and there are multiple factors to consider to ensure you purchase a water heater that fits your space and meets your needs. The most important metric to gauge whether a water heater will meet your needs is the water heater’s first hour rating—the number of gallons the heater can supply per hour. This measure is identified based on total tank capacity, the source of heat, and the size of the gas burner or electric element.

The U.S. Department of Energy provides a worksheet to determine your peak hour demand—the number of gallons used during your household’s busiest hot water consumption hour—which you can use as a baseline to equate to a water heater’s first hour rating. Look for water heaters that are rated within one or two gallons of your peak hour demand.

The storage volume—the total volume of hot water that’s contained within the storage tank—matters less than the first hour rating. Nevertheless, this is typically the leading metric in how water heaters are listed for sale. A small, 50–60 gallon storage tank is sufficient for an individual or a couple. A medium, 80-gallon tank will work well for three or four people, whereas a large, 100-gallon tank is recommended for more than four people.

A few more additional factors to consider include anti-scale devices, the type of drain valve, digital displays, and the water heater warranty.

Anti-scale devices

Some water heaters have features that reduce the buildup of mineral scale at the bottom of the tank. This can extend the life of your water heater and keep it in good condition for quite some time.

Drain valves

The drain valve is found near the base of the water heater—this is connected to a garden hose to drain the water heater. Brass drain valves are typically last longer than plastic and can withstand higher water temperatures.

Digital displays

These can help you monitor water levels, display pressure readings, and set the water temperature more easily. They can even let you set your water heater on vacation mode to increase energy efficiency when you’re away.


Many manufacturers offer a warranty on their water heaters. Look for gas water heaters with a 12-year warranty—though most warranties run for three to 12 years, you’ll want to choose a water heater with the longest warranty available. As with any product warranty, read the fine print and be prepared to ask store clerks or sales consultants relevant questions to identify what the warranty covers and for how long.

Best gas water heaters


Rheem G100-80 Natural Gas Universal Commercial Water Heater


Standard storage


With 75,000 BTU and a universal space saver design, this gas water heater has intuitive controls and makes it easy to operate.


3-year tank warranty; 1-year parts warranty

Takagi T-H3S-DV-N Condensing High Efficiency Natural Gas Indoor Water Heater


High efficiency


This compact gas water heater has computerized safety features, no pilot light to worry about, and is built to deliver on high efficiency. Not to mention, it comes with a lead-free component and has a low carbon footprint.


5-year parts warranty; 1-year labor warranty

Eccotemp i12-NG Indoor Tankless Water Heater




This gas-powered tankless water heater activates only on demand, reducing energy consumption. It has a sleek, modern design with a tempered glass panel and LED display controls. It also features fully automatic temperature controls with an energy saving mode and child lock technology.


2-year limited manufacturer's warranty

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