Your Guide to Water Heater Expansion Tanks

The natural expansion that occurs during the heating process can overtax plumbing pipes on systems with tank-style heaters. A safety mechanism known as a water heater expansion tank can help avoid the risk of damage to your plumbing system due to the built-up pressure from thermal expansion.

Since hot water expands, a tank-style water heater creates additional water volume every time it heats water. For example, the cold water in a standard 50-gallon water heater expands to 52 gallons when heated to 120 degrees Fahrenheit. Those extra two gallons of water volume are all it takes to increase the pressure in your plumbing system, and over time, that increased burden can cause damage to the water heater, plumbing fixtures and the water pipes themselves. A water heater expansion tank essentially protects your tank-style water heater and plumbing system by serving as an overflow vessel for the excess water volume a water heater creates as it heats water.

Who Needs a Water Heater Expansion Tank?

Many homes are designed with an open system that allows expanding water to reenter the municipal water supply. Homeowners with open systems are rarely at risk for any of the problems associated with the excess volume their tank-style water heaters may create, since the water can just flow back into the main water supply.

However, if your home has a closed water system, the extra water pressure created by thermal expansion can build up very rapidly, causing damage. That’s because closed systems prevent excess water from re-entering the water main, and it therefore has no other place to go. That’s why most cities’ building codes require homes with closed plumbing systems to install expansion tanks. If you have a closed water system in your home, and you do not already have an expansion tank, you should have one installed as soon as possible to prevent harm to your water heater or plumbing.

How a Water Heater Expansion Tank Is Installed

Even if your home has an open water system, consider installing an expansion tank to reap the benefits. For example, having an expansion tank helps prevent dripping faucets and running toilets by preventing the extra built-up pressure in the system from reaching your plumbing fixtures and causing damage.

Your expansion tank does not need to be located close to the water heater. It is most common to see installation using a “T” at the cold inlet on the water heater. However, from a functional standpoint, the tanks can really be installed anywhere along the cold water line before it enters the water heater.

For people who are considering getting a new tank-style water heater installed, it’s a smart idea to request a quote for the installation of an expansion tank at the same time, since the benefits far outweigh the work and cost involved.

If you live in Bucks or Montgomery County, Pennsylvania, and would like to discuss your options for water heater service – including installation of an expansion tank – contact your local professionals at Nu-Temp Heating and Cooling. We have the tools and expertise to work on most makes and models of water heaters, and we offer free in-home consultations and up-front pricing on every service we provide.