The highest rated Rheem water heater is the PROG50-38N RH58 38K BTU Natural Gas Water Heater, which is rated by Amazon at 4.5 stars. Customers state that the water heater works very fast and is well-insulated.
However, the Rheem PROG50-38N RH58 water heater only has two reviews. The Rheem water heater with the most favorable reviews is the RTE 13 Electric Tankless Water Heater, which is rated by over 400 people on Amazon at 4 stars. Many customers state that this water heater saves them money on their energy costs and is energy-efficient. However, the reviewers note that wires that come with the heater barely fit inside the connectors when adding the heater to one's home.