Because water expands when heated, excess pressure inside a water heater tank needs to escape. In the past, the pressure would force water in the tank to drain back out into the water supply where it came from.
Today, the water main is designed to prevent the backward flow of water, known as backflow, by means of a check valve. The check valve prevents wastewater from inside the home from returning to the water supply, where it could contaminate the supply of fresh water.
How a Water Heater Expansion Tank Works
A water heater expansion tank is another small tank that is attached to the water supply pipe of the water heater. The expansion tank is designed to handle the thermal expansion of water as it heats up in the water heater, preventing excessive water pressure.
If water pressure gets too high, it can damage valves in plumbing fixtures, joints in supply pipes, and the water heater itself. Expanding water from the water heater flows into the expansion tank, relieving water pressure in the system.
Have more questions about water heater expansion tanks? Contact the experts at ABC Southwest for answers!
What if my water heater doesn’t have an expansion tank?
Most homes that have a check valve on the water main do not have an expansion tank, since it wasn’t required until recently. This may or may not cause excessive pressure buildup, depending on the specific design of the plumbing in the house.
If you are noticing that washers in plumbing fixtures are deteriorating rapidly, or water is dripping from the relief valve on the water heater, it may be wise to add an expansion tank. It can be low-cost insurance against more costly damage to your home’s plumbing system.
Ready to install a water heater expansion tank in your Sarasota-area home? Schedule now with the water heater experts at ABC Southwest!
Frequently Asked Questions About Water Heater Expansion Tanks
What is a water heater expansion tank?
A water heater expansion tank is a small tank installed on the water supply line that absorbs excess pressure created when water heats and expands inside a closed plumbing system.
What does a water heater expansion tank do?
An expansion tank prevents pressure buildup by allowing heated water to expand safely, protecting the water heater, plumbing fixtures, and pipes from damage.
Do I need an expansion tank on my water heater?
Homes with closed plumbing systems, such as those with a check valve or backflow preventer, typically require an expansion tank to control pressure and meet modern plumbing codes.
What happens if a water heater does not have an expansion tank?
Without an expansion tank, increased pressure can cause relief valves to drip, shorten the lifespan of plumbing components, and potentially damage the water heater or pipes.
Can a failing expansion tank cause plumbing problems?
A failed expansion tank can lead to excessive pressure, leaks at fixtures, water heater relief valve discharge, and increased stress on the plumbing system.
Helpful Water Heater Expansion Tank Resources for Homeowners
- The Benefits of a Water Heater Expansion Tank
- The ABCs of Plumbing: Water Heater TPR Valve
- How to Flush a Water Heater
Get Help With Water Heater Expansion Tank Installation
If you’re unsure whether your water heater needs an expansion tank or you’re noticing signs of excess pressure, the licensed plumbers at ABC Southwest Plumbing & Air Conditioning can help. Our team inspects your system, confirms code requirements, and installs expansion tanks correctly to protect your water heater and plumbing system.
Contact ABC Southwest today to schedule water heater service and get expert guidance for your home in Southwest Florida.
