If your water heater is equipped with an expansion tank, you’ll need to maintain it. Even with the rise of tankless water heaters, millions of homes throughout the United States use a traditional tank-based water heater. Tank-based water heaters feature a large water tank. Some of them, however, may feature a smaller tank as well. Known as an expansion tank, you’ll need to maintain it to protect it from premature wear and tear.

Overview of Expansion Tanks and How They Work

An expansion tank is a small tank that’s used to hold expanded, pressurized water. Heat causes things to expand. Water heaters, of course, expose water to heat. Some of them feature a gas-powder burner assembly, whereas other water heaters feature an electric heating element. Regardless, they will heat the water in the large tank.

As the water in the large tank becomes warmer, it will expand. Some homes have an open water system that allows the expanded water to recede back into the water line. But other homes have a closed water system. A closed water system means water can enter the home, but it can’t leave the home. Homes with a closed water system such as this typically require an expansion tank for their tank-based water heaters.

Inspect for Corrosion

You should regularly inspect the expansion tank for signs of corrosion. Expansion tanks are available in different materials. Some of them are made of stainless steel, whereas others are made of aluminum or even copper. Over time, expansion tanks may corrode. As the water inside of them oxidizes with the material from which they are made, corrosion will occur.

Test the Pressure

Another essential form of maintenance is testing the pressure. All expansion tanks are designed to hold expanded, pressurized water. Water expands as it heats up, thus increasing the pressure of the water. Expansion tanks, though, are designed for a specific amount of pressure measured in pounds per square inch (PSI). Your expansion tank may have a PSI rating of 20 to 40. You can test the pressure to ensure it matches the PSI rating.

Get It Professionally Serviced

Even if you’re able to test the pressure yourself, you should still get your expansion tank – as well as your water heater itself – professionally serviced. Professional water heater services involve a more thorough inspection and test to ensure that everything is working as intended. Investing in an annual water heater service can help you avoid more costly problems with your water heater or expansion tank later down the road.