[villagetinker]

Several neighbors as well as myself have had the expansion tank bladders fail, we have all replaced these ourselves, here is basically what is involved.

Lowe's sells 2 of these, one is rated for 1 year warranty and one for 6 year warranty. The 6 year warrant one exactly matches what was installed originally.

1. Turn of power to hot water heater.
2. Turn off water supply to hot water heater.
3. connect a hose to the drain valve of the hot water heater and open the valve to reduce pressure.
4. Using two (2) wrenches remove the existing expansion tank. Keep a towel handy as you will have some leakage.
5. Take a water pressure gauge and measure the pressure at a hose bib.
6. Pre-charge the new expansion tank to that pressure with an air compressor.
7. Apply two layers of Teflon tape to the threads of the new expansion tank.
8. Screw the new tank in place and hand tighten.
9. Using two (2) wrenches tighten the new expansion tank.
10. Turn on the water supply and check for leaks.
11. If you have a small leak try tightening the expansion tank, be sure to use two wrenches against each other.
12. Turn the power back on to the hot water heater.

Hope this helps.