The Homeowner’s Guide to 40-Gallon Gas Water Heaters


When it’s time to buy a new car or phone, it’s normal to do your research to make sure you’re getting the best fit for you. The same should go for when you need a new water heater in your home.

 40-Gallon Gas Water Heaters

But for many of our customers, looking at water heaters in a home improvement store can be overwhelming. If you’re not sure where to start, we’re here to help. In this article, we’ll explain why 40-gallon gas water heaters are one of the most popular types of water heaters, and explain some of the different features you may find.

How gas water heaters work

Tank water heaters are typically available in two different heat sources – electricity and natural gas. In most cases, gas water heaters are less expensive to operate on a monthly basis due to lower energy costs.

The water heater is connected to the natural gas line. The gas flows to a burner, which ignites and heats up the water in the tank. The water is stored and kept warm in the tank until an outlet in the home is opened such as a sink faucet, shower faucet, outdoor spigot, or appliance.

Types of venting

The heating process of burning natural gas creates a combustion gas that needs to be vented outside to prevent dangerous carbon monoxide from entering the home. There are two ways a gas water heater can be vented.

  • Draft induced water heaters use a fan to suck the combustion gas up through a vertical exhaust pipe, usually through a chimney
  • A power-vented water heater uses a blower to push the combustion gas through a PVC plastic pipe that runs horizontally through the home to reach the exterior

Recommend size for your household

When choosing a new tank water heater, one of the first considerations is what capacity of hot water your household will need. A good starting point is to look at how many people are in your household.

A 40-gallon gas water heater can typically store enough hot water for 2-4 people. Since the average U.S. household is 2.6 people, the 40-gallon tank is one of the most popular sizes of tank water heaters. If you have more than four people in your home, you may need a larger size, such as 50 or 60 gallons.

Ultra-low NOx water heaters

In certain parts of California, any new water heater installed in a home must be an ultra-low NOx model. NOx stands for nitrogen oxides, which are gases that are released by machines that burn natural gas, including tank water heaters.

To reduce the amount of NOx being released in the air that can harm the environment, California’s South Coast Air Quality Management District (SCAQMD) and the San Joaquin Valley Air Pollution Control District (SJVAPCD) passed laws that require new water heaters that are rated for NOx emissions of less than 14 nanograms per joule. To make things simpler, you can look an ultra-low NOx water heaters, which means it complies with these new California laws.

Water Heater Experts Serving Los Banos, Turlock, Merced and Patterson

There are many benefits to buying a new water heater from a local plumber. As professionals, we have a deeper understanding of the products we carry as well as local codes and laws. We can also help you maintain the warranty of your new water.

For help picking out the best gas water heater for your home, call All American Plumbing, Heating & Air at 209-509-4448.