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

Two-stage comfort for large homes with 5-ton cooling systems — maximum blower capacity at an 80% AFUE price. The Goodman GR9T800805CN delivers 80,000 BTU of two-stage heating at 80% AFUE in a wide 21" upflow cabinet specifically sized for larger 5-ton R-32 cooling systems. The key difference from the GR9T800804CN? This unit's blower is engineered to move the higher 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. Run at lower output on mild days for quieter, more efficient operation — then ramp up to full power when the cold really hits.

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
• Two-stage gas valve — runs at lower output on mild days for gentler, quieter cycling and more even room temperatures, then ramps to full power when temperatures really drop
• 9-speed ECM blower motor — precisely sized for 5-ton system airflow requirements, delivering quiet, precise air distribution and outperforming older PSC motor units throughout your home
• Upflow / horizontal installation — flexible placement in basements, closets, or utility rooms to suit your home's layout
• Wide 21" cabinet with 5-ton blower — the correct furnace pairing for 2-5 ton R-32 cooling systems — if your system is a 5-ton condenser or heat pump, this is the unit 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
• 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 — acts like a "check engine light" for your furnace, pinpointing issues fast and cutting service time and costs
• 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 GR9T800804CN. This unit — the GR9T800805CN — is specifically for homes with 5-ton cooling systems.

Specs:

• Input: 80,000 BTU | Output: 64,000 BTU
• AFUE: 80%
• Cabinet Width: 21"
• Stages: Two
• Blower Motor: 9-Speed ECM (5-Ton)
• 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.