The Rheem XR90 is a 29-gallon gas water heater that outperforms standard 50-gallon models with much faster recovery. When you talk about tank water heaters, part of the discussion is about recovery rates – or how fast the hot water replenishes itself in the tank. The Rheem XR90 can provide 90 gallons of hot water in an hour, even though the tank only holds 29 gallons. That’s nearly 50% more hot water for you than conventional tank water heaters. The compact size fits where other models won’t – and it’s maintenance free, with no filter to clean. The XR90 has an energy efficiency of .70, which exceeds Energy Star Phase II requirements. Rheem also offers a 50 gallon energy efficient gas tank water heater with a .67 energy factor, again qualifying it for the Energy Trust Rebate. The higher efficiency means more hot water at a lower operating cost and offers a power flue damper, helping retain heat. Standard water heaters produce extremely hot air during combustion, which moves the combustion gases quickly up the chimney. With a fan assisted draft inducer, the Rheem keeps more heat in the water and less up the chimney and still creates the proper draft to expel the combustion gases. The PROG5040NRH67PD has a patented magnesium anode rod (dip tube) that helps protect the tank from rust.