Originally Posted by villagetinker (Post 2351122)

Also, the typical lifetime of an expansion tank is 5 to 7 years, then they need to be replaced. The simple test to see if the tank is still good is tap the side of the tank, above the weld it should ring (like a bell) below the tank it will sound dull, if the whole tank sounds dull, the bladder has failed and the tank needs to be replaced.
NOTE: Lowes (and probably others) sell at least 2 versions one for wells and one for public water service, be sure to get the one for public water service, the one for wells has a lower pressure rating.

Originally Posted by CFrance (Post 2351330)

VT, are you saying that if the bladder goes you need to replace the whole tank? We replaced the bladder a couple years ago, but the tank seems fine. Our house was built in 2011. I'm guessing the tank will go soon, but don't know what to look for. (that was a two-part question, sorry!)

Originally Posted by Bill14564 (Post 2351337)

There are two tanks, the hot water tank and the expansion tank. The expansion tank is small, about 15 inches high, and attaches to a single water line, usually above the hot water tank.

The expansion tank contains a bladder. The bladder cannot be replaced, if it goes bad then the entire expansion tank needs to be replaced.

The hot water tank does not need to be replaced if the bladder in the expansion tank goes bad.

Originally Posted by CFrance (Post 2351330)

VT, are you saying that if the bladder goes you need to replace the whole tank? We replaced the bladder a couple years ago, but the tank seems fine. Our house was built in 2011. I'm guessing the tank will go soon, but don't know what to look for. (that was a two-part question, sorry!)

Originally Posted by Bill14564 (Post 2351337)

There are two tanks, the hot water tank and the expansion tank. The expansion tank is small, about 15 inches high, and attaches to a single water line, usually above the hot water tank.

The expansion tank contains a bladder. The bladder cannot be replaced, if it goes bad then the entire expansion tank needs to be replaced.

The hot water tank does not need to be replaced if the bladder in the expansion tank goes bad.