Thermal Expansion Statement

When water is heated it expands, the check valve at the meter has closed your water system, and in some cases this may contribute to a condition known as thermal expansion.

Watts Bar Utility District has installed a double check valve at the customer’s meter service. This has been done to prevent the backflow of water from the customer’s home into the utility’s water supply. Under certain conditions the backflow of your home’s water could possibly contaminate the utility’s water supply.

When water expands it causes water pressure in your lines to increase. All household plumbing has a certain amount of thermal expansion, but in some cases some household plumbing may have excess thermal expansion. You may have this condition if your faucets, commodes, or water heater pop off valve drips intermittently. Excessive thermal expansion can easily be cured by installing a thermal expansion tank on your cold water line before the hot water heater; your local plumber will be able to advise you on what needs to be done.

Watts Bar Utility is responsible for clean and safe drinking water to all of its customers.



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