We replaced our gas water heater about 5 years ago because it was noisy (boiling noises in the sediment that had built up over the years, draining didn't help). The water heater is right under our bedroom and J is a very light sleeper.

I briefly considered trying to do it myself, but the idea of wrestling a new tank down the basement stairs, and the old one back up, made that thought vanish quickly.

Two guys did it in about half a day. Around $1200 installed. It was worth it.

Good luck!

Cheers,
Scott.