Amtrol ST-1 THERM-X-TROL Expansion Tank
The Therm-X-Trol ST-1 absorbs thermal expansion and pressure surge in tankless and point-of-use water heaters to protect the heat exchanger. Simple to install, the ST-1 features patented air cell technology and requires no precharge adjustment or maintenance. With a 304 stainless steel waterway and a 7-Year limited warranty, the ST-1 delivers big protection in a compact size.