Checking for product changes
Buy Now, Pay Later
As low as
$10.79
/ mo
Learn more
- – 6-month term
- – No impact on credit
- – Instant approval decision
- – Secure and straightforward checkout
Ready to go? Add this product to your cart and select a plan during checkout.
Payment plans are offered through our trusted finance partners Klarna, PayTomorrow, Affirm, Afterpay, Apple Pay, and PayPal. No-credit-needed leasing options through Acima may also be available at checkout.
Learn more about financing & leasing here.
Free shipping on this product
Non-returnable item
Learn more
Non-returnable. Transportation of this item is subject to hazardous materials regulation
View our full returns policy here.
Availability:
In Stock.
Arrives
Monday, Jul 21
Features
- Metal
- Made in USA
- Accepts expanded water caused by thermal expansion
- Returns water to the system when hot water is used
- Prevents the relief valve from going off
- Inline thermal expansion tank
- Accepts expanded water caused by thermal expansion
- Returns water to the system when hot water is used
- Prevents dripping faucets, intermittent toilet fill and pressure relief valve discharge
- Protects water heater, appliances and fixtures
Description
AMTROL ST-5 Thermal Expansion Tank From the Manufacturer Amtrol invented the thermal expansion tank to control pressure build-up in closed, hot water systems. This prevents the water heater pressure relief valve from opening, saves energy and eliminates a potential safety hazard. All Therm-X-Trol expansion tank
Manufacturer: AMTROL
Part Number: ST-5
Item Weight: 3 pounds
Product Dimensions: 8 x 8 x 13 inches
Item model number: ST-5
Is Discontinued By Manufacturer: No
Size: one-size
Color: White
Material: Molded Polypropylene
Power Source: Ac/dc
Item Package Quantity: 1
Included Components: Expansion tank
Batteries Included?: No
Batteries Required?: No
Date First Available: January 16, 2007
Frequently asked questions
If you place your order now, the estimated arrival date for this product is:
Monday, Jul 21
This item is non-returnable:
Non-returnable. Transportation of this item is subject to hazardous materials regulation
View our full returns policy here.
Non-returnable. Transportation of this item is subject to hazardous materials regulation
View our full returns policy here.
- Klarna Financing
- Affirm Pay in 4
- Affirm Financing
- Afterpay Financing
- PayTomorrow Financing
- Financing through Apple Pay
Learn more about financing & leasing here.
Top Amazon Reviews
High quality product and service when I needed it. First up, because of the stainless steel nipple, you must use a lead free brass or bronze service tee (https://www.amazon.com/dp/B01BUX9WXG?psc=1&ref=ppx_yo2_dt_b_product_details), and not copper. Must be mounted upright. The Schrader valve on the bottom allows the tank to be preloaded to other than the 50psi it comes with. I set mine to 60psi because I have the input water regulator set for 64psi. A clever feature is the included "Turbulator;" a small plastic part that fits above the attachment nipple and creates turbulence to help make sure the water in the tank remains fresh, and helps retard the growth of bacteria. The Turbulator in the box arrived broken--crushed under the tank--but I called Amtrol and they sent me a replacement.
...
show more
Reviewed in the United States on September 24, 2021 by Mr. Picky
This expansion tank is of excellent quality. installation was quick and easy. Saved me a ton of money by doing it myself as opposed to the plumber doing it. Took less than 15 minutes from start to finish.
Reviewed in the United States on May 24, 2024 by Mk5
Easy to install with brass union
Reviewed in the United States on August 12, 2024 by Ben S.
While talking to a neighbor about his recent water heater purchase I was informed that our local code now requires an expansion tank to be installed on the water supply system. This guy only buys the best and this is what is installed in his house. I also did some research on my own and many of the reviews for competitors tanks say they have a very short life and are accompanied by tales of water damage and leaking. It is a nice little tank- I only needed a small one because I have a tankless water heater so there is a minimal amount of thermal expansion. Mine is installed with the air fitting up and it is adjacent to my water meter - I chose this orientation after reading that if the tank bladder were to ever fail, the air pocket at the top would continue to provide expansion in the line, as for placement - the tank can be installed anywhere on your cold water line unless your local code restricts you for some reason. Also remember to be sure to strap or anchor the tank in some way if possible to keep the weight of of your pipes.
...
show more
Reviewed in the United States on April 30, 2014 by rauw
I like the sight glass on the bottom air-fill Schrader valve that shows any water from a failed synthetic rubber air pressure bladder/diaphragm, necessitating tank replacement. I wish it also had a pressure gauge for accurate initial pressurization and ongoing monitoring to indicate any pressure drop over time, so I could add air as required. The air volume in the lower half of the tank is so small, that any momentary leakage while disconnecting a tire pump or pressure gauge from valve stem after charging, drops the internal pressure. I finally used a small compressor with a pressure regulator set to 80 psi and a hold-on air chuck to pressurize the bottom half of the tank to equal my static water pressure before turning the water back on to fill and pressurize the top half of the tank. It took a lot of force to push the plastic “Turbulator” down to seat it into the connector opening against the top of the pre-charged rubber diaphragm. I heard a brief “psst” that scared me that I had just punctured the diaphragm, but hopefully it was just an air bubble trapped between the diaphragm and the side of the top half of the tank. Again, a pressure monitoring gauge would tell if it’s maintaining pressure or not. My kitchen faucet and tub spout still drip intermittently, so adding the thermal expansion tank didn’t solve that problem. I designed and fabricated my own custom wall mount cradle out of scrap materials I had left over from other projects.
...
show more
Reviewed in the United States on March 30, 2022 by Silvertabby Silvertabby
proper sizing easy and ready to use right out of the box
Reviewed in the United States on April 15, 2024 by Mike
Installed tank yesterday. Easy to install and fit pipes exactly perfect
Reviewed in the United States on February 22, 2024 by Gary volovnik
I had to send back the Watts unit I purchase previous to this as they advertised it as made in USA and it was not. Paid a few bucks more and got this one and is as advertised.
Reviewed in the United States on April 18, 2023 by Bryan Welsh