Amtrol ST-12 Thermal Expansion Tank
Key features
- •Eliminates the waste of energy and water, thus saving money
- •Prevents the relief valve from going off
- •Protects the water heater and plumbing fixtures from premauture failure
- •Prevents a dangerous pressure build-up in the system
Amtrol ST-12 Thermal Expansion Tank
List Price: $111.98$100.78DEALYou Save: $11.20 (10%)
Free shippingFree Returns – 30 daysFree Order CancellationSecure Payment2–3 Days DeliveryGet It June 23, 2026In Stock (16)No marketing spamNo account requiredFulfilment by FedEx / Amazon / UPS / ShipwirePayPal / Card Buyer Protection
Customer Reviews
Reviews sourced from verified Amazon purchasers4.6
out of 5
Based on 10 reviews
5★
100%
4★
0%
3★
0%
2★
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1★
0%
Super easy install, great customer service
Scott✓ Verified Purchase•September 7, 2023
The hardest part of the installation has to do with putting in the sharkbite tee - the tank install was simple.
Before installing you'll need to make sure the pressure in the tank is the same as your home water pressure. You can get a house bib mount water pressure gauge from Lowe's (or Amazon) for ten bucks and the tank is filled with a standard valve like you'd see on a car or bicycle tire.
I used three turns of Teflon tape, which wasn't in the instructions, to make sure nothing leaked.
The little plastic Turbulator device was broken when I received the unit but I just called the US based company and they shipped me a replacement at no charge.
Time will tell as to whether the tank holds up under my 50 psi with 80 gallon tank from the 70s installation but so far all is well.
Before installing you'll need to make sure the pressure in the tank is the same as your home water pressure. You can get a house bib mount water pressure gauge from Lowe's (or Amazon) for ten bucks and the tank is filled with a standard valve like you'd see on a car or bicycle tire.
I used three turns of Teflon tape, which wasn't in the instructions, to make sure nothing leaked.
The little plastic Turbulator device was broken when I received the unit but I just called the US based company and they shipped me a replacement at no charge.
Time will tell as to whether the tank holds up under my 50 psi with 80 gallon tank from the 70s installation but so far all is well.
Replaced old one
timothy r wolbert✓ Verified Purchase•August 7, 2023
Worked well
Solved our home's hypertension crisis.
Fourday✓ Verified Purchase•August 4, 2023
By random chance I checked our homes water pressure and it was 105 psi. We ended replacing the pressure regulator (replaced the guts, made it easy) and the pressure was back to 70 psi, however it would creep "randomly" up to 115-120 psi. I finally noted that this was only when the water heater was heating the water. I should also add that we have a hot water circulation pump with a check valve. After a little research it looked like the builder forgot to add an expansion tank. After I installed the tank our water pressure has been holding at 70 psi with maybe a 5 psi +/- fluctuation. This was my first time using PEX and it wasn't too difficult. Just make sure to match the air bladder psi with that of the pressure set to the regulator.
Thermal expansion
dan✓ Verified Purchase•May 28, 2023
Great product Excellent quality
Works as expected
Bruce L Sr.✓ Verified Purchase•May 19, 2023
Replaced a defective tank. New tank was easy to set up (pressurize) and install. No leaks!
Instructions are clear. If you have never done this before, suggest you watch a couple of "plumbing how to" videos.
Instructions are clear. If you have never done this before, suggest you watch a couple of "plumbing how to" videos.
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