Goodman 40K BTU 96% AFUE Two-Stage Downflow Furnace | GD9T960403BN

Premium two-stage efficiency for small homes — the highest efficiency Goodman offers in a downflow configuration. The Goodman GD9T960403BN delivers 40,000 BTU of two-stage heating at 96% AFUE in a compact 17.5" downflow cabinet purpose-built for closet, alcove, and attic installations. Run quietly at 60% output on mild days for gentler, more even comfort — then step up to full 100% power when winter arrives. Maximum efficiency, smart two-stage comfort, and a downflow design that fits where upflow furnaces simply can't go.

Why You'll Love It:

• 96% AFUE efficiency — converts 96 cents of every energy dollar into heat, the highest efficiency rating available for a two-stage gas furnace — a significant upgrade over 80% and 92% models
• 40,000 BTU input / 38,400 BTU output — ideal heating output for small homes without oversizing or wasted capacity
• Two-stage gas valve — runs at 60% output on mild days for gentler, quieter cycling and more even room temperatures, then ramps to 100% full power when temperatures really drop
• 9-speed ECM blower motor — precise, whisper-quiet airflow that outperforms older PSC motor units, delivering consistent comfort even in the tightest spaces
• Downflow / horizontal installation — purpose-built for closets, alcoves, and attic installs where air needs to travel downward through the duct system
• 17.5" cabinet width — compatible with 1-2 ton R-32 cooling systems for a complete, balanced home comfort setup
• Heavy-duty aluminized-steel tubular primary heat exchanger — engineered for long-lasting durability and efficient heat transfer with wrinkle-bend technology for added dependability
• Stainless steel secondary heat exchanger — extracts additional heat from exhaust gases to achieve the industry-leading 96% AFUE efficiency rating
• 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
• PVC/plastic venting required — high-efficiency condensing operation requires plastic vent pipe, not metal
• Low NOx emissions — meets air quality requirements for nationwide installation
• 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

⚠️ Downflow / Horizontal installation only. For upflow applications, see the GR9T960403AN.

⚠️ PVC/Plastic venting required — this is a 96% AFUE condensing furnace and cannot use metal flue venting.

Specs:

• Input: 40,000 BTU | Output: 38,400 BTU
• AFUE: 96%
• Cabinet Width: 17.5"
• Stages: Two
• Blower Motor: 9-Speed ECM
• Fuel Type: Natural Gas (LP Convertible)
• Installation: Downflow / Horizontal
• Venting: PVC / Plastic
• Voltage: 115V
• Compatible Cooling: 1-2 Ton R-32 Systems

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