40 Gal. Short Water Heater, Residential, Gas, 40,000 BTU

Rheem Professional Classic Plus 40-Gallon Natural Gas Water Heater – Atmospheric Vent, 40,000 BTU

The Rheem PROG40S-40N-RH62 is a 40-gallon natural gas water heater from the Professional Classic Plus series, designed for residential applications requiring reliable recovery, durable tank protection, and consistent performance. This unit features a 40,000 BTU input and a first-hour delivery rating suitable for mid-range domestic hot water demand.

Equipped with an atmospheric venting configuration, the unit is compatible with standard vertical vent installations using B-vent. The model includes electronic gas control for precision temperature regulation and integrated diagnostics for streamlined maintenance. Its tank protection includes a durable glass lining and a magnesium anode rod to resist corrosion in potable water conditions.

Technical Specifications

• Fuel Type: Natural Gas
• Tank Capacity: 40 gallons nominal
• BTU Input: 40,000 BTU/hr
• Recovery Rate: 40.4 gallons per hour at 90°F rise
• Energy Factor (EF): 0.62
• Venting: Atmospheric, vertical 3” or 4” B-vent
• Ignition System: Push-button pilot ignition
• Water Connections: 3/4" NPT top-mounted
• Tank Lining: Fused glass coating with anode rod
• Height: 53-7/8 inches
• Diameter: 23 inches
• Warranty: 6-year limited warranty on tank and parts

Design and Installation Notes

The unit’s compact footprint and standard connections simplify installation in retrofit and new construction applications. Atmospheric venting requires a proper vertical flue and adequate combustion air. Installation must comply with local gas, plumbing, and mechanical codes. The model includes a factory-installed temperature and pressure relief valve and meets low-NOx emissions standards where required.

Contractor Use Case

The PROG40S-40N-RH62 is a practical solution for residential installations where a moderate hot water load is anticipated. Its standard venting and gas input rating make it compatible with existing infrastructure in many retrofit projects. The electronic gas control and self-diagnostic capabilities assist in post-installation service and troubleshooting.