Rheem ProTerra Hybrid Water Heater Comparison

Rheem ProTerra hybrid water heaters heat water with a heat pump that draws warmth from the surrounding air, with electric elements as backup on the 240 V models. This page compares the ProTerra models we carry: 50, 65 and 80 gallon units for a 208/240 V, 30 amp circuit, and 40 and 50 gallon plug-in units that run on a 120 V, 15 amp circuit. For each model the tables give capacity, Uniform Energy Factor (UEF), first-hour rating, electrical requirement and tank dimensions. Below the tables you will find Rheem’s guidance on the air volume and temperature a heat pump water heater needs, which often decides whether a hybrid will fit the space where the old tank stood. Select a model to open its product page and specification sheet.

ProTerra 240 V hybrid models

ProTerra 120 V plug-in models

Height and diameter are the tank dimensions from the product specifications. Allow extra room above for water connections and air flow, and check the specification sheet for the overall installed height.

How to choose

• Size by first-hour rating, not gallons alone. Rheem’s method is to estimate the hot water your household uses in its busiest hour and choose a heater whose first-hour rating meets that figure. If two showers, a laundry load and kitchen use add up to 55 gallons, look for a first-hour rating of 55 gallons or more.
• Check the air volume. Rheem states that its heat pump water heaters need at least 700 cubic feet of surrounding air, for example a 7 ft × 10 ft × 10 ft room. An open garage or basement normally meets this. A closet does not without a louvered door, a gap under the door or ducting, as described in the installation instructions.
• Check the temperature of the space. The ProTerra specification sheet lists an ambient operating range of 37°F to 145°F for heat pump operation. The unit cools the air around it while it runs.
• Match the electrical supply. A new or altered circuit is work for a licensed electrician. The 240 V models listed here need a 208/240 V circuit with a 30 amp breaker, which is what most standard electric tank heaters already use. The 120 V plug-in models listed here require a dedicated 120 V, 15 amp circuit and suit homes replacing a gas heater where no 240 V circuit exists.
• Measure the height. The 80 gallon tank is 74-3/16" tall against 61-3/4" for the 50 gallon. Hybrids are taller than standard electric tanks of the same capacity because the heat pump sits on top.
• Plan a condensate drain. A heat pump water heater produces condensate that must be piped to a drain or a condensate pump.

Common questions

How much space does a Rheem ProTerra hybrid water heater need?

Rheem specifies a minimum of 700 cubic feet of air around the unit. In a smaller room the manufacturer calls for added ventilation, such as a louvered door or ducting. Clearances for service access are given in the installation manual.

What is the difference between the 240 V and the 120 V ProTerra?

The 240 V hybrid models have a heat pump plus 4,500 W backup elements and connect to a 30 amp circuit. The 120 V plug-in models connect to a standard 120 V, 15 amp circuit. In the 50 gallon size the first-hour rating is 67 gallons for the 240 V model and 55 gallons for the 120 V model.

Which ProTerra size should I pick: 50, 65 or 80 gallon?

Compare first-hour ratings with your busiest hour: 67 gallons for the 50 gallon model, about 75 to 77 gallons for the 65 gallon models and 87 gallons for the 80 gallon model. Then confirm that the taller, wider tank fits the space.

What does the SO at the end of a ProTerra model number mean?

Models ending in SO include Rheem’s LeakGuard system with an automatic shut-off valve. Models ending in 30 are the 30 amp models without the shut-off valve.

Related collections

• Heat pump water heaters
• Residential electric tank water heaters
• Rheem 50 gallon water heaters
• All Rheem products