Rheem 40-gallon (6-year warranty $850 / 9-year warranty $950 / 12-year warranty $1,100) Rheem 50-gallon (6-year $950 / 9-year $1,100 / 12-year $1,250) AO Smith's 40-gallon (6-year warranty $900 / 9-year warranty $1,000 / 12-year warranty $1,100) AO Smith's 50-gallon (6-year warranty $1,000 / 9-year warranty $1,100 / 12-year warranty $1,250)