AMTROL ST-5 Thermal Expansion Tank

Seems like a quality piece at a fair price. It does the job and is small enough where it worked out beautifully with not interfering with my gas Hot water heater vent piping!

Good product. worked well.

Worked great and easy to charge and install.

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.

It's perfect for my new water heater. It was easy to install and no leakage or interference with water flow.

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.

My old failed tank was the same model - this new one was dead easy to swap in. Following the instructions I lowered the pressure a little to match line pressure, put tape on the threads, pushed in the plastic "turbulator" thing, and screwed it on. Very easy repair saving a lot compared to calling a plumber - and I hate plumbing and usually pay someone else to do it.

This unit is a direct replacement from the one I had on my water heater. It was a perfect fit, unscrew the original and put on the provided Teflon tape and screw it on. Simple and easy.Update Sep/2024 - Tank failed in about a year. Seller did not respond to warranty inquiry. Not sure if they are even the real deal.The second tank blew after 6 months and give run around on warranty. Don't trust this brand, useless warranty! Don't believe just try claiming the warranty and you will get the run around.These tanks are garbage. The leak senor does not work. My tank diaphragm rupture for months and the indicator shows nothing. All gimmick. In addition, the tank is not stainless steel it will rust like crazy. Check out the photos.The third tank blew even before I installed it. Pressure the tank to 80 PSI source PSI and it just pop! Was rated for 150 right?