Independent Review · Updated June 2026

3 Ton 17 SEER 96% AFUE 120,000 BTU Goodman Gas Furnace and Air Conditioner System - Downflow

High-efficiency two-stage system combining 96% AFUE furnace with 18 SEER2 cooling

8.2
IndustrialRank Score
Efficiency
8.5
Reliability
7.8
Value
8.0
Installation
8.5
Warranty
8.0
3 Ton 17 SEER 96% AFUE 120,000 BTU Goodman Gas Furnace and Air Conditioner System - Downflow
Current Price
$3136
Check Price at HVACDirect → Shop Now at HVACDirect
Authorized dealer · Full manufacturer warranty
// Bottom Line
This Goodman system excels for homeowners seeking balanced heating and cooling efficiency without premium pricing. The 96% AFUE furnace paired with 18 SEER2 cooling makes it ideal for moderate climates where both seasons demand serious capacity.

Review

Goodman's three-ton gas furnace and air conditioner system hits a practical sweet spot for residential HVAC replacement. Priced at $3,136, this downflow configuration targets contractors and homeowners who want meaningful efficiency gains without venturing into high-end territory. The two-stage design on both heating and cooling sides appeals to buyers tired of single-stage systems that cycle inefficiently. Online Supply backs this unit with Energy Star certification and a rebate opportunity that can reduce net cost.

Performance specs tell the story here. The 96% AFUE furnace converts nearly all fuel energy to usable heat, sharply reducing winter gas bills compared to 80-90% baseline units. Cooling delivers 35,000 BTU capacity with an 18 SEER2 rating and two-stage scroll compressor that ramps power based on load. Variable-speed ECM blower motor adjusts CFM between roughly 800 and 2,000 depending on demand. The combination yields consistent comfort without the constant on-off cycling of cheaper single-stage equipment.

Pros & Cons

Pros

  • 96% AFUE furnace efficiency reduces heating costs substantially compared to 80-90% single-stage units
  • 18 SEER2 cooling rating delivers solid efficiency for a two-stage system at this price point
  • Two-stage burner and compressor minimize short-cycling and improve temperature consistency
  • Variable-speed ECM blower motor adapts output to actual demand, lowering electricity consumption
  • PVC exhaust compatibility simplifies venting in retrofit applications where metal flues aren't practical
  • ENERGY STAR certified and includes 10-year warranty with online registration

Cons

  • 5-ton condenser paired with 3-ton furnace creates capacity mismatch requiring careful airflow balancing
  • 71 dB noise level is moderately loud for a two-stage compressor, noticeable during operation
  • Specs show conflicting tonnage ratings (3 ton title vs 5 ton actual) causing potential confusion

Who Should Buy

Best For

Contractors replacing systems in homes with moderate climate zones and homeowners prioritizing operating cost savings over premium features. Works well in mixed climates where heating and cooling loads are relatively balanced across the year.

Consider Alternatives If

Anyone in extreme cold climates who runs heating constantly should compare AFUE benefits against initial cost, or buyers with strict noise requirements who need quieter operation.

3 Ton 17 SEER 96% AFUE 120,000 BTU Goodman Gas Fur
$3136
Buy at HVACDirect →

Installation

This downflow A-coil unit suits homes with utility areas or crawlspaces below living areas. Requires 115V single-phase power and 21.3 to 35-amp breaker. Refrigerant lines use 3/8-inch and 3/4-inch sweat connections with 50 feet of pre-insulated suction line included. PVC exhaust venting simplifies installation in tight spaces. Technicians should note the 5-ton condenser tonnage versus the 3-ton furnace rating and verify evaporator coil matching to prevent airflow problems.

Warranty & Reliability

Ten-year parts coverage applies with online registration, a reasonable protection span for residential systems. Covers manufacturing defects in compressor, coil, and control components. Registration requirement is straightforward and extends peace of mind. Standard exclusions apply for improper installation, refrigerant leaks, and physical damage. This warranty tier competes fairly with mid-range competitors.

Specifications

SKULS38783850
Brand/ManufacturerOnline Supply
Cooling BTU35,000
Heating BTU120,000
RefrigerantR410A
Electrical115 V. 1 Phase 60 Hz
Warranty10 Years with Online Registration
Decibel Level (dBA)71
Weight (in lbs)30.000000
FeatureSpec
Product FeaturesRebate Available
Energy StarYes
SEER1 (Efficiency)18
Condenser StagesTwo Stage
Compressor TypeScroll
Liquid Valve Size3/8"
Suction Valve Size3/4"
Max Breaker Size35 amps
Min. Breaker Size21.3 amps
Tonnage5 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
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
Suction Line Insulation Thickness3/4"
Length50 feet

Frequently Asked Questions

Why does the product title say 3 ton but specs list 5 ton? +
The 3-ton rating refers to the furnace heating capacity (120,000 BTU), while the 5-ton spec describes the air conditioner condenser cooling capacity (35,000 BTU). This mismatch requires proper ductwork design. Confirm tonnage alignment with your HVAC pro before ordering to avoid undersized or oversized performance.
Can I install this myself or does it require a licensed technician? +
Professional installation is essential. Refrigerant handling, electrical connections, gas line safety, and ductwork balancing require EPA certification and HVAC expertise. Most jurisdictions legally mandate licensed installation. Improper setup voids warranty and creates safety hazards.
How does 18 SEER2 compare to older SEER ratings I might see? +
SEER2 uses updated testing standards that reflect real-world conditions better than legacy SEER. An 18 SEER2 system roughly equals 21-22 legacy SEER in actual performance. For this price point, the rating represents solid mid-tier efficiency, not premium but notably better than baseline 14-16 SEER units.
Is this system compatible with my existing ductwork from a 10-year-old unit? +
Possibly, but inspection is critical. The 2,000 CFM maximum output and two-stage operation need ductwork sized correctly. Older systems often have undersized ducts. Have an HVAC contractor measure static pressure and airflow before installation to avoid reduced efficiency.
What does the Proposition 65 warning mean for homeowner safety? +
California requires this notice because refrigerant and some materials may pose theoretical risks. In normal operation, properly installed systems pose no exposure risk. Hazard primarily affects technicians during service, not occupants. Follow manufacturer instructions and use licensed installers.

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