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Therm-X-Trol ST-12 Expansion Tank

$8164
  • Provides efficient water and energy usage
  • Prevents premature failure in plumbing fixtures and water heaters
  • Eliminates hazardous pressure build-up in the system
  • See More Details

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Price:
$8164

Product Overview

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. AMTROL ST-12 Applications: Residential water heaters, Laundromats, dormitories, office/apartment buildings, restaurants, etc.
  • Eliminates the waste of energy and water, thus saving money
  • Protects the water heater and plumbing fixtures from premature failure
  • 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
  • A professional plumber should check the complete system, including the Therm-X-Trol, yearly and more frequently as the system ages
  • Click here to check out our buying guide on water heaters
  • California residents

Info & Guides

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Therm-X-Trol ST-12 Expansion Tank

Specifications

Dimensions

Product Depth (in.)
11
Product Diameter (in.)
11 in
Product Height (in.)
15
Product Width (in.)
9

Details

Container Size (gallons)
4.4
Finish
white
Finish Family
White
Maximum Capacity (gallons)
3.2
Nominal Tank Capacity (gallons)
4
Pack Size
1
Product Weight (lb.)
11
Returnable
90-Day

Questions & Answers

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Customer Reviews

  • 4.8
    out of 45 reviews
  • 100% recommend this product
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Showing 1-10 of 45 reviews
Went by the ratings to try to get the best rated item that will hopefully last.
Went by the ratings to try to get the best rated item that will hopefully last.
by Rick
  • Verified Purchase
  • Recommended Product
1 person found this helpful
Does What it is supposed to!
City installed new water meters with a check valve in the system. Old system did not have check valve. Since the new water meter was put in my water heater started to relieve thermal caused pressure through the safety valve. Always water in the bucket as our basement has no drains. Our city water pressure was 70 PSI. Matched the tank pressure to this, installed the tank, and the water heater safety valve has not released any water due to pressure. Good value and easy to install.
by Orkie
    • Recommended Product
    3 people found this helpful
    Works as advertised
    After installing a solar hot water system that utilizes a 120 gallon tank, I started having elevated water pressure (at times) in the house. I was also getting pipe "hammering," and was afraid I'd end up with a broken pipe. My previous hot water heater was a 50 gallon unit which must have had the same issues, but to a much lesser extent. I never noticed the problem until the larger tank was installed. The Amtrol thermal expansion tank seems to have solved the problems. It's been in for about two weeks now, and haven't had a single high pressure episode, or any pipe hammering since. The unit appears to be of very high quality, and I had no problems installing it...very simple. I ended up making my own mounting bracket for the unit. There are commercially available brackets made, but the Home Depot did not carry them, or offer them on their website. To save the cost + shipping from the other suppliers, I built a simple unit out of plywood, and a couple of large hose clamps.
    by twmax
    • DIY
    • Verified Purchase
    • Recommended Product
    2 people found this helpful
    Easy install and directions are great!
    The thermal expansion tank was very easy to install as were the directions to follow. The thermal expansion tank was a replacement for a unit which was worn out. The tank was a near identical replacement for the exixting unit. I would highly recommend this product if you have a hot water heater that has a back flow preventor installed somewhere in line to allow the water to expand. Othewise you may create a situtation where the pipes may burst due to over pressure.
    by Toby422
    • Pro
    • Verified Purchase
    • Recommended Product
    5 people found this helpful
    Delivered on time. Worked as advertised....
    Delivered on time. Worked as advertised.
    by LOREN
    • Verified Purchase
    Rating provided by a verified purchaser...
    Rating provided by a verified purchaser
    by HomeDepotCustomer
    • Verified Purchase
    Rating provided by a verified purchaser...
    Rating provided by a verified purchaser
    by HomeDepotCustomer
    • Verified Purchase
    Just make sure that the plumber tape is going in the right direction, if you have to take the tan...
    Just make sure that the plumber tape is going in the right direction, if you have to take the tank off for any reason be careful oh, you have to let the pressure out of the tank first. I learned the hard way
    by Jtm528
    • Verified Purchase
    • Recommended Product
    Rating provided by a verified purchaser...
    Rating provided by a verified purchaser
    by Yashu
    • Verified Purchase
    Rating provided by a verified purchaser...
    Rating provided by a verified purchaser
    by HomeDepotCustomer
    • Verified Purchase
    Showing 1-10 of 45 reviews