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 system with solid 96% AFUE and 16 SEER1 efficiency

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
$3770
Check Price at HVACDirect → Shop Now at HVACDirect
Authorized dealer · Full manufacturer warranty
// Bottom Line
This Goodman system is ideal for budget-conscious homeowners and contractors who want respectable efficiency without premium pricing. The 96% AFUE furnace and 16 SEER1 condenser deliver measurable savings on both heating and cooling bills while maintaining proven Goodman reliability.

Review

The Goodman CAPT3743D4 is a conventional split-system combination furnace and air conditioner rated at 3 tons cooling and 3.5 tons heating capacity. At $3770, it sits squarely in the mid-market segment where contractors and homeowners expect solid performance without flagship pricing. This downflow configuration works well in closets, attics, or basement installations where horizontal or vertical discharge fits the layout. Goodman's reputation for straightforward engineering and parts availability makes this a familiar choice for replacement projects.

The furnace delivers 120,000 BTU of heating output at 96% AFUE, meaning only 4% of fuel energy is lost through the PVC exhaust. Cooling capacity reaches 36,000 BTU, and the condenser achieves 16 SEER1 efficiency using R410A refrigerant and a scroll compressor. Two-stage operation on both the burner and compressor reduces short-cycling and cycling losses. The variable-speed ECM blower motor adjusts output up to 2000 CFM, keeping noise reasonable at 70.4 dB while matching actual heating and cooling demand.

Pros & Cons

Pros

  • 96% AFUE furnace converts nearly all fuel to usable heat, reducing natural gas or propane waste
  • 16 SEER1 cooling efficiency qualifies for ENERGY STAR, supporting lower summer cooling costs
  • Two-stage burner and two-stage compressor provide modulation for comfort and efficiency
  • Variable-speed ECM blower motor adjusts CFM from quiet operation to 2000 CFM capacity
  • PVC exhaust flue requirement simplifies venting in modern installations
  • 10-year warranty with online registration covers parts and labor on both furnace and coil

Cons

  • 16 SEER1 is mid-tier efficiency, not top-tier like 18+ SEER2 systems available at higher price points
  • 70.4 dB noise level is acceptable but not the quietest option for noise-sensitive installations
  • Scroll compressor is durable but less efficient than some newer variable-capacity designs

Who Should Buy

Best For

Homeowners replacing aging systems who want reliable performance at $3770 without overspending on premium efficiency. Contractors seeking proven Goodman equipment for mid-range residential projects in moderate climates.

Consider Alternatives If

Buyers in extreme climates or those prioritizing cutting-edge efficiency should explore 18+ SEER2 systems or variable-capacity compressors despite higher upfront costs.

3 Ton 15 SEER 96% AFUE 120,000 BTU Goodman Gas Fur
$3770
Buy at HVACDirect →

Installation

This system arrives configured for downflow or horizontal discharge, simplifying field orientation. Suction and liquid lines measure 7/8 inches and 3/8 inches respectively, with sweat valve connections for standard brazing. Electrical demand runs 115V, 1-phase, 60 Hz, requiring a 21.8 to 35 amp breaker. PVC exhaust flue is required, eliminating costly metal venting. Most experienced HVAC technicians complete installation in one to two days.

Warranty & Reliability

Goodman includes a 10-year parts and labor warranty when you register online at no charge. This covers both the furnace and evaporator coil, providing meaningful protection against compressor failure or heat exchanger defects. The warranty does not cover normal maintenance, refrigerant losses from leaks beyond manufacturing defects, or damage from improper installation.

Specifications

SKUCAPT3743D4
Brand/ManufacturerGoodman
Cooling BTU36,000
Heating BTU120,000
RefrigerantR410A
Electrical115 V. 1 Phase 60 Hz
Warranty10 Years with Online Registration
Decibel Level (dBA)70.4
Weight (in lbs)75.000000
FeatureSpec
Energy StarYes
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
Height30"
Width24.5"
Depth21"
ResourcesCAPT Installation Manual CAPT 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.
AHRI Certificate Number7368845
Airflow DirectionDownflow/Horizontal
Exhaust Flue RequirementPlastic / PVC
Product FeaturesRebate Available
Furnace Efficiency / AFUE96%
Blower MotorVariable Speed - ECM
Maximum CFM2000
ConfigurationUpflow / Downflow
Burner StagesTwo
Fuel TypePropane, Natural Gas
Liquid Line3/8"
Suction Line7/8"
StyleA-Coil

Frequently Asked Questions

How does 16 SEER1 compare to newer SEER2 ratings I see advertised? +
SEER1 and SEER2 use different testing standards. SEER2 ratings are roughly 15 to 20 percent lower numerically. This unit's 16 SEER1 is approximately 13 to 14 SEER2 equivalent, placing it in the mid-tier for modern efficiency. Premium systems reach 18+ SEER2, but cost significantly more.
Can I install this in my upflow attic space if I need it downflow? +
Yes. The spec sheet shows this model supports both upflow and downflow configurations. You may need field modifications to the return and supply ductwork, so confirm with your installer before purchase. Goodman provides installation guidance in the CAPT Installation Manual.
What does 96% AFUE actually save me compared to an 80% furnace? +
A 96% furnace converts 96 cents of every fuel dollar into heat. An 80% furnace wastes 20 cents. Over a heating season, a 96% AFUE unit saves roughly 16 to 20 percent on gas costs depending on your climate and usage. Savings vary by region and thermostat settings.
Is the variable-speed blower motor worth the extra cost? +
Yes. The ECM motor ramps down when heating or cooling demand is low, reducing electricity consumption and noise. During peak load, it reaches 2000 CFM. Over a year, variable-speed blowers save 10 to 15 percent on fan energy versus single-speed models, paying back the upgrade cost.
What if I find a refrigerant leak after installation? +
Manufacturing defects in the sealed system are covered by the 10-year warranty. Leaks caused by installation damage or corrosion are not. Your technician should pressure-test and evacuate properly to avoid this issue.

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