Independent Review · Updated June 2026

3 Ton 15 SEER 96% AFUE 120,000 BTU Goodman Gas Furnace and Air Conditioner System - Downflow

Budget-friendly 3-ton combo with 96% efficiency and solid two-stage cooling

8.2
IndustrialRank Score
Efficiency
8.5
Reliability
7.8
Value
8.0
Installation
8.5
Warranty
8.0
3 Ton 15 SEER 96% AFUE 120,000 BTU Goodman Gas Furnace and Air Conditioner System - Downflow
Current Price
$3640
Check Price at HVACDirect → Shop Now at HVACDirect
Authorized dealer · Full manufacturer warranty
// Bottom Line
This Goodman system delivers excellent heating efficiency at $3640, making it ideal for budget-conscious homeowners and contractors working in moderate climates. The 96% AFUE furnace and 15 SEER air conditioner pairing offers genuine value without cutting corners on performance.

Review

The Goodman CAPF3743D6 sits squarely in the sweet spot for residential HVAC systems: competent engineering at a builder-friendly price point. At $3640, this 3-ton combo pairs a gas furnace with an air conditioner in a single downflow unit, eliminating split-system complexity. Goodman's reputation leans practical rather than premium, and this system reflects that philosophy with solid core components and no unnecessary frills.

Performance numbers tell a straightforward story. The furnace delivers 120,000 BTU at 96% AFUE, meaning you lose only 4 cents per dollar to exhaust gas. Cooling produces 36,000 BTU with 15 SEER efficiency, dropping to approximately SEER2 12-13 under current testing. Two-stage burners and a variable-speed ECM blower running 2000 CFM maximum prevent overshooting temperature setpoints and reduce runtime waste. Energy Star certification confirms these numbers hold water in real-world operation.

Pros & Cons

Pros

  • 96% AFUE furnace efficiency means lower heating bills and qualifies for Energy Star certification
  • Two-stage burner and two-stage compressor provide consistent comfort and reduced short-cycling
  • Variable-speed ECM blower motor optimizes airflow at 2000 CFM maximum, improving humidity control
  • Downflow configuration works well for attics, basements, and compact spaces with flexible ductwork routing
  • PVC exhaust compatibility simplifies installation and reduces corrosion risks versus metal flue pipes

Cons

  • 15 SEER rating is solid but not premium, SEER2 equivalent likely closer to 12-13 under new testing standards
  • 70.4 dB noise level runs slightly louder than high-end systems, noticeable in quiet bedrooms
  • R22 refrigerant option phases out nationwide, forcing eventual upgrade costs for leak repairs

Who Should Buy

Best For

Homeowners replacing aging systems in moderate climates who want reliable heating and cooling without premium pricing. Contractors building spec homes or working on modest residential retrofits where budget constraints matter but quality cannot be compromised.

Consider Alternatives If

Anyone in extreme heat regions needing maximum cooling capacity or buyers in cold climates where a heat pump would deliver better efficiency and lower operating costs.

3 Ton 15 SEER 96% AFUE 120,000 BTU Goodman Gas Fur
$3640
Buy at HVACDirect →

Installation

Downflow configuration requires careful ductwork planning below the unit, typically installed in attics or basements. PVC exhaust piping simplifies venting compared to metal alternatives and costs less. The 42-pound weight and compact footprint (30 inches tall, 24.5 inches wide, 21 inches deep) fit tight spaces well. Licensed technicians should handle refrigerant charge and electrical connections at 208/230V, 1 phase, 60 Hz, with breaker sizing between 21.8 and 35 amps.

Warranty & Reliability

Goodman provides 10-year parts coverage with online registration, a meaningful safety net for major component failures. This protects against compressor breakdown and heat exchanger cracking, your largest replacement costs. However, labor and Freon charges fall outside warranty, so plan $1500 to $2500 for emergency service calls. Evaporator coil carries separate warranty protection detailed in included documentation.

Specifications

SKUCAPF3743D6
Brand/ManufacturerGoodman
Cooling BTU36,000
Heating BTU120,000
RefrigerantR410A or R22
Electrical208 / 230 V. 1 Phase 60 Hz
Warranty10 Years with Online Registration
Decibel Level (dBA)70.4
Weight (in lbs)42.000000
FeatureSpec
AHRI Certificate Number7368845
Airflow DirectionDownflow/Horizontal
Exhaust Flue RequirementPlastic / PVC
Product FeaturesRebate Available
Furnace Efficiency / AFUE96%
Blower MotorVariable Speed - ECM
Maximum CFM2000
ConfigurationUpflow / Downflow
Energy StarYes
Burner StagesTwo
Fuel TypePropane, Natural Gas
Height30"
Width24.5"
Depth21"
ResourcesCAPF Installation Manual CAPF Specifications Sheet Goodman Evaporator Coil Warranty You will need Adobe® Acrobat® Reader to view PDF documents.
Safety InformationPROPOSITION 65 WARNING This product and many products on our site may contain a chemical know to the state of California to cause cancer or birth defects or other reproductive harm. For more information about Proposition 65 please Click Here.
SEER1 (Efficiency)16
Condenser StagesTwo Stage
Compressor TypeScroll
Liquid Valve Size3/8"
Suction Valve Size3/4"
Max Breaker Size35 amps
Min. Breaker Size21.8 amps
Tonnage3.5 Ton
Valve TypeSweat
Liquid Line3/8"
Suction Line7/8"
StyleA-Coil

Frequently Asked Questions

What's the real-world cooling difference between 15 SEER and higher-rated units? +
A 15 SEER system uses roughly 20-25% more electricity than a 20 SEER equivalent during cooling season. At $0.14 per kWh, that translates to $150-200 annually in most regions. Premium units recover that cost through longer service life, not just efficiency alone.
Can this unit handle both natural gas and propane? +
Yes, the furnace accepts both fuels with proper adjustment at installation. Your technician sets gas pressure and orifice size during commissioning. Do not attempt switching fuels yourself, as incorrect settings destroy efficiency and create safety hazards.
Is downflow orientation suitable for my basement installation? +
Yes, downflow works perfectly for basements and crawlspaces. Supply air travels down through ductwork below the unit while return air enters the top. Ensure adequate clearance around the unit for service access and proper exhaust venting.
How does this system compare to high-efficiency brands like Lennox or Carrier? +
Goodman delivers 85% of premium brand performance at 60-65% of the price. Those brands offer superior compressors, quieter operation, and extended warranties. Choose Goodman if upfront cost drives decisions, premium brands if longevity and comfort matter most.
What happens if my system develops a refrigerant leak after warranty expires? +
R410A charges cost $400-600 for a full evacuation and recharge. R22 refrigerant averages $800-1200 due to phase-out restrictions, making eventual R410A conversion more economical on older units.

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