Cherokee and Fulton counties are updating the infrastructure of their water systems. They have installed new backflow prevention devices at each home or business connection point along the main lines. They recommend that all residents bring their homes up to the new code standard by installing a thermal expansion device to create a closed system. A thermal expansion tank is a simple pressurized cylinder of air that creates positive water pressure in the plumbing system.
Thermal Exapnsion Tank

What is Thermal Expansion?

Thermal expansion is a term used to describe the circumstance of water expanding in volume as it is heated.

What causes Thermal Expansion?

All water heaters, regardless of heat source (gas, oil, electric, solar, geothermal, or indirect), can suffer the effects of thermal expansion. This increase in volume and pressure must be relieved in some way.

Why are Thermal Expansion Control Devices Necessary?

The installation of a thermal expansion tank in the cold water line of the water heater can protect the system from the damaging effects of thermal expansion and increased pressure.

What is a Thermal Expansion Tank?

When water is heated in a closed system it expands. Water is not compressible, therefore, the additional water volume created has to go someplace. When an expansion tank is installed the excess water enters the pre-pressurized tank. As the temperature and pressure reaches its maximum, the diaphragm flexes against an air cushion (air is compressible) to allow for increased water expansion. When the system is opened again or the water cools, the water leaves the tank and returns to the system.

When to Install a Thermal Expansion Tank

If the county has installed a backflow preventer on your water meter you should install a thermal expansion tank on your water heater’s piping. If you’re installing a new water, then it is required by Section 607.3.2 of the standard Plumbing Code.

The licensed and insured plumbers at Champion Plumbing & Drain Cleaning in Canton, GA are your local plumbing codes experts.

Do you have questions about water heaters? We’ve got answers! Join our Facebook group Plumbing Questions and Answers, or check out our page About Plumbing. If you want to learn how to properly maintain your water heater read our article about Water Heater Maintenance. Feel free to call us at 770-480-5077.