Rheem 40 Gallon Water Heaters

Every 40 gallon Rheem we stock, gas and electric, on one page: Professional Classic®, Professional Classic Plus® and Professional Prestige® residential tanks, light-duty commercial electric, and models listed for manufactured housing.

Gas or electric follows the house. Replace like for like unless you are prepared to run a new gas line or a 240 V circuit. Gas input on these runs from 30,000 to 50,000 Btu/h, and a higher input recovers faster after a long shower. The residential electrics are 240 V at 4.5 or 5.5 kW; the light-duty commercial electrics are 208 V at 6 kW.

On gas, venting is the real decision. Atmospheric models vent by natural draft into an existing B-vent or chimney. Powered damper (PD) models close the flue between cycles to cut standby loss. Power vent (PV) models use a blower to push exhaust through plastic pipe out a side wall, and power direct vent (PDV) models also bring combustion air in from outside. Match the vent to the house before comparing anything else.

On electric, height is the fit. The same 40 gallons comes in a medium height for a low ceiling or under a stair, and a tall, narrower tank for a tight closet. Measure the space, including clearance above for the connections.

Manufactured homes need a manufactured-housing model. The MH units here are listed for that use, including direct-vent versions that take combustion air from outside the closet.

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