Frequently Asked Questions
Q. "What is thermal expansion?"
A. When water is heated, it expands in volume by 2 - 3%, depending upon the initial and final temperature. This can mean as much as three or four extra gallons of water in a closed system. If there is no demand for hot water, the expanded volume of water has no place to go. Since water is not compressible, the expanded water cannot be accommodated in the piping system, and therefore it creates hydraulic pressure, exerting a potentially hazardous stress on the system. To learn more about thermal expansion and how you can manage it, click here.
Q. "What is a closed system?"
A. It is a system that uses a pressure reducing valve when water service pressure is too high for residential applications, usually above 80PSI.
Q. "What size expansion tank should I order for my water heater?"
A. This depends on the size of your water heater and your water pressure. For most small water heaters usually the A101 works. Please refer to this thermal expansion tank quick-sizing chart to find the appropriate thermal expansion tank for your system.
Q. "Your typical installation diagram shows mounting these expansion tanks in a vertical position. Can they be mounted horizontally?"
A. Yes. According to the manufacturer, the A101, A102, A103 and the A104 expansion tanks can be installed horizontal, vertical or even diagonal. Inlet threads up, down or sideways, it doesn't matter. These thermal expansion tanks can be mounted in any orientation and the tank will function correctly.