Amtrol ST-12 (Therm-X-Trol) is a water heater expansion tank, designed for use in domestic hot water heating systems to eliminate the potential hazards of water expansion. Water heater expansion tank is commonly installed in a domestic hot water system that contains a backflow preventer, a check valve or a pressure reducing valve. The patented InSight Indicator Cap changes its color when the tank needs to be replaced.
Applications: Residential water heaters, laundromats, dormitories, office/apartment buildings, restaurants, etc.
Features: - Eliminates the waste of energy and water, thus saving money;
- Protects the water heater and plumbing fixtures from premature failure;
- Reduces potential safety hazards associated with thermal expansion;
- Prevents a dangerous pressure build-up in the system;
- Prevents the relief valve from going off;
- Therm-X-Trol brand is the #1 choice of Professional Installers;
- NSF/ANSI 61®, IAPMO, SBCCI & City of Los Angeles listings.
- Factory pre-charged 40 psig
- System connection: 3/4" male threaded
- Stainless steel system connection
- Max. operating temperature: 200F
- Max. operating pressure: 150 psi
- Expansion tank volume: 4.4 gallons
- Max. acceptance factor: 0.73
- Height: 15"
- Diameter: 11"
- Shipping weight: 9 lbs.
5-year manufacturer's warranty.
Verified
Purchase
Amtrol expansion tank Product is great. Installation was a breeze.
By Ed (from Groton, MA) on
02/20/2019
This product came up to my expectations/ "The order was delivered extremely quickly 2 days after the order was placed. My plumber installed the
tank in 5 minutes. The old tank was full of water.
I was extremely satisfied !"
By Alex (from Twp. of Washington, NJ) on
11/29/2011
reliable product great quality. and they have the best price
By mary (from pa) on
08/23/2011
Ask a Question
Can this tank be mounted with the water line connection at the bottom rather than at the top?
Amtrol's manual does not have any restrictions concerning the mounting the tank under or over the line. The main condition is that it must be vertical in order to avoid stress on the connection point. So the answer is yes, as long as you level the expansion tank properly.
By PexUniverse Customer Service on 08/31/2015
can it be mounted horizontalygs6bk
Amtrol allows only for vertical installation of this expansion tank.
By PexUniverse Customer Service on 07/11/2012 
