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

Rheem Professional Classic 40-Gallon Natural Gas Water Heater – Atmospheric Vent

The Rheem PROG40-40N-RH62 is a 40-gallon, natural gas, atmospheric vent water heater engineered for standard residential applications. Featuring a 40,000 BTU input and a first-hour delivery rating that supports medium-demand households, this model is part of Rheem’s Professional Classic series, offering a balance of efficiency, capacity, and durability required for reliable hot water delivery.

Designed with a self-diagnostic gas control valve and integrated safety features, this unit is intended for vertical venting through a standard B-vent flue. The PROG40-40N-RH62 meets or exceeds minimum energy efficiency requirements with a 0.62 Uniform Energy Factor (UEF) and is equipped with factory-installed components to simplify installation.

Technical Specifications

• Model: PROG40-40N-RH62
• Capacity: 40 gallons
• Input: 40,000 BTU/hr (natural gas)
• Recovery Rate: 40.4 GPH @ 90°F rise
• Uniform Energy Factor (UEF): 0.62
• Water Connection: 3/4" NPT (top-mounted)
• Height: 60-1/2" to top of draft hood
• Diameter: 20-1/4"
• Venting Type: Atmospheric, 3" or 4" vertical B-vent
• Warranty: 6-year limited tank and parts

Key Features

• Self-Diagnostic Gas Valve: Integrated LED system for fast service troubleshooting.
• Maintenance-Free Combustion System: No filter to clean, reducing service frequency.
• Low NOx Burner: Compliant with standard emissions requirements (not for Ultra-Low NOx jurisdictions).
• High Recovery Rate: Delivers consistent performance in mid- to high-demand scenarios.
• Glass-Lined Tank: Protects against corrosion for extended life expectancy.

Installation Considerations

This model is compatible with standard 3" or 4" vertical B-vent terminations. Cold water inlet dip tube features integrated heat trap to reduce standby heat loss. Units ship with factory-installed temperature and pressure relief valve (T&P), but expansion tank requirements should be confirmed per local code. Clearance requirements must be observed for venting and service access.

Contractors should confirm gas line sizing (½" minimum, ¾" preferred depending on run length), combustion air provisions, and manifold pressure. Total installation time can vary based on location, venting configuration, and local permitting requirements.

Professional Use Case

Suitable for typical 2–4 person residences, this unit delivers dependable hot water without unnecessary complexity. It is a solid choice for replacement installations where access, venting, or footprint may be limited. The Rheem PROG40-40N-RH62 integrates well into existing residential system designs, and with its diagnostic valve and maintenance-free operation, it reduces post-install service callbacks.