Do I Need a Water Heater Expansion Tank? Most modern-day water heaters are tankless, heating water on demand instead of keeping it stored, come with built-in thermal protection, or are installed ...

When a water heater is connected to a closed system, an expansion tank must be installed to prevent excessive pressure caused by thermal expansion.

Although I recommend having thermal expansion devices installed by a licensed plumber, the installation of a thermal expansion tank or valve is relatively easy if you are handy.

If thermal expansion of the water creates excess pressure within the heater, water is forced into the expansion tank, keeping pressure levels within the normal operating range of the heater.

Microsoft’s new building is an energy plant. The Thermal Energy Center is the unlikely centerpiece of a 3-million-square-foot addition to the tech giant’s campus in Redmond, Washington.

Many water heaters feature an expansion tank to protect the system. Here's what a water heater expansion tank does and how you know if your system needs one.