Goodman 80,000 BTU 80% AFUE Single-Stage Gas Furnace Upflow/Horizontal 21" Cabinet 5-Ton R-32

Same 80,000 BTU heating power, bigger blower — built for large homes with 5-ton cooling systems. The Goodman GR9S800805CN delivers 80,000 BTU of single-stage heating at 80% AFUE in a wide 21" upflow cabinet equipped with a high-capacity 5-ton ECM blower. The key difference from the GR9S800804CN? This unit's blower is engineered to move the higher 2,000 CFM airflow volume that 5-ton systems demand — making it the correct furnace choice when your cooling system is a 5-ton condenser or heat pump. Same affordable 80% AFUE price point, same proven Goodman reliability — just the right blower for your system size.

Why You'll Love It:

• 80% AFUE efficiency — converts 80 cents of every energy dollar into heat, keeping operating costs predictable without overpaying for efficiency ratings designed for larger or colder applications
• 80,000 BTU input / 64,000 BTU output — confident, consistent heating for large homes paired with 5-ton cooling systems without oversizing or wasted capacity
• Single-stage operation with 9-speed ECM blower motor — steady, even airflow throughout your home with quieter operation and better humidity control than older PSC motor units
• 5-ton blower sizing at 2,000 CFM — the critical difference from the GR9S800804CN, this unit is specifically engineered to handle the high airflow requirements of 5-ton R-32 cooling systems
• Upflow / horizontal installation — flexible placement in basements, closets, or utility rooms with left or right gas and electrical connections for added installation flexibility
• Wide 21" cabinet — compatible with 2-5 ton R-32 cooling systems — if your system is a 5-ton condenser or heat pump, this is the furnace you need
• Heavy-duty aluminized-steel tubular heat exchanger — engineered for long-lasting durability and efficient heat transfer with wrinkle-bend technology for added dependability
• Foil-faced insulated heat exchanger cabinet — minimizes heat loss during operation and keeps the cabinet airtight for quieter, more economical performance
• Silicon nitride igniter — more durable than older hot surface igniters, reducing maintenance calls and replacement costs over the life of the unit
• Self-diagnosing control board with constant memory — stores the last fault codes so your technician can diagnose issues fast, cutting service time and costs
• Compatible with electronic air cleaners and humidifiers — wire directly to the low-voltage terminals on the control board for seamless indoor air quality integration
• LP convertible — easily field-converted to propane with optional kit, giving you fuel flexibility for your home
• Metal flue venting required — straightforward installation using standard metal duct for safe, code-conforming exhaust
• R-32 compatible — future-ready refrigerant support for pairing with modern R-32 cooling systems
• AHRI Certified and ETL Listed — independently verified for safety and performance
• Made in the USA — designed, engineered, and assembled domestically

⚠️ Metal venting required — this is an 80% AFUE furnace and requires metal flue venting, not PVC.

⚠️ Not sure which 21" model you need? If your cooling system is 2-4 tons, see the GR9S800804CN. This unit — the GR9S800805CN — is specifically for homes with 5-ton cooling systems.

Specs:

• Input: 80,000 BTU | Output: 64,000 BTU
• AFUE: 80%
• Cabinet Width: 21"
• Stages: Single
• Blower Motor: 9-Speed ECM (5-Ton)
• Blower CFM: 2,000
• Fuel Type: Natural Gas (LP Convertible)
• Installation: Upflow / Horizontal
• Venting: Metal
• Voltage: 115V
• Compatible Cooling: 2-5 Ton R-32 Systems

Warranty: 10-year limited parts + lifetime heat exchanger warranty with online registration within 60 days of installation.