Independent Review · Updated June 2026

4 Ton 15 SEER 97% AFUE 100,000 BTU Goodman Gas Furnace and Air Conditioner System - Downflow

High-efficiency modulating gas furnace with 97% AFUE and variable-speed blower.

8.2
IndustrialRank Score
Efficiency
8.5
Reliability
7.8
Value
8.0
Installation
8.5
Warranty
8.0
4 Ton 15 SEER 97% AFUE 100,000 BTU Goodman Gas Furnace and Air Conditioner System - Downflow
Current Price
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// Bottom Line
This Goodman system excels for homeowners upgrading from older single-stage furnaces, especially those in moderate climates where the modulating burner and ECM blower will cycle frequently. The 97% AFUE rating delivers meaningful heating cost savings, and ENERGY STAR certification confirms genuine efficiency gains.

Review

This Goodman combination system pairs a high-efficiency gas furnace with a standard air conditioning condenser in a downflow configuration. The 97% AFUE heating efficiency and modulating burner design place it firmly in the contractor-grade segment, competing against mid-tier units from Lennox and Carrier. The system carries ENERGY STAR certification, suggesting genuine efficiency gains over baseline models. Goodman's reputation centers on reliable, affordable equipment that performs solidly without premium pricing.

Performance specifications reveal a well-balanced unit for temperate climates. The furnace delivers 100,000 BTU heating output with a modulating burner that adjusts flame intensity rather than cycling on and off, reducing temperature swings. The variable-speed ECM blower motor ranges from 0 to 2000 CFM, matching airflow to actual heating demand. Cooling arrives via a scroll compressor at 45,500 BTU (approximately 3.8 tons), with 16 SEER1 efficiency. The 115V single-phase electrical design fits standard residential circuits with 23.9 to 40 amp breaker sizing.

Pros & Cons

Pros

  • 97% AFUE modulating burner reduces heating costs compared to standard 80-85% units by approximately 15-20%
  • Variable-speed ECM blower motor adjusts airflow from 0 to 2000 CFM, improving comfort and reducing noise
  • ENERGY STAR certified with 16 SEER1 cooling efficiency on the air conditioner side
  • Scroll compressor is proven reliable in residential applications with lower failure rates than reciprocating designs
  • PVC plastic exhaust flue compatible with modern venting codes and retrofit installations
  • Modulating gas valve provides better temperature control than single-stage burners

Cons

  • Spec sheet lists 4 ton cooling capacity in title but shows 5 ton tonnage and 45,500 BTU cooling output, creating confusion about actual system size
  • 73 dB noise level is moderately loud, higher than premium multi-stage systems at 68-70 dB
  • Single-stage compressor cannot modulate cooling like the heating side, limiting part-load efficiency during mild weather
  • No pricing information provided despite major purchasing decision factor

Who Should Buy

Best For

Contractors replacing failed furnaces in homes with existing ductwork compatible with downflow configuration, and homeowners in zones 4-6 seeking to cut heating bills without replacing entire HVAC systems. This suits retrofits where AC tonnage is less critical than furnace efficiency.

Consider Alternatives If

Anyone needing precise cooling capacity for hot climates should look elsewhere, as the single-stage compressor and conflicting cooling tonnage specs create uncertainty. Homeowners prioritizing ultra-quiet operation should consider premium brands with multi-stage compressors.

4 Ton 15 SEER 97% AFUE 100,000 BTU Goodman Gas Fur
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Installation

Downflow configuration suits homes with crawl spaces or basements and existing horizontal ductwork. The unit measures 34.5 inches tall, 21 inches wide, and 28.75 inches deep, fitting most utility closets or furnace rooms. Installation requires plastic PVC venting, standard copper lineset connections (3/8 inch liquid, 1 1/8 inch suction), and proper refrigerant charge. ECM blower integration simplifies wiring compared to older single-speed motors.

Warranty & Reliability

Goodman provides 10 years of parts warranty with online registration, a solid mid-range coverage period. This protects against compressor failure and heat exchanger cracks, the two costliest repair scenarios. Registration is essential, as many claims require proof. Compared to premium brands offering 12-year warranties, this represents reasonable protection for equipment typically lasting 15-18 years with maintenance.

Specifications

SKULS381183850
Brand/ManufacturerOnline Supply
Cooling BTU45,500
Heating BTU100,000
RefrigerantR410A
Electrical115 V. 1 Phase 60 Hz
Warranty10 Years with Online Registration
Decibel Level (dBA)73
Weight (in lbs)48.000000
FeatureSpec
ReplacesGSX16S481
Energy StarYes
SEER1 (Efficiency)16
Condenser StagesSingle Stage
Compressor TypeScroll
Liquid Valve Size3/8"
Suction Valve Size7/8"
Max Breaker Size40 amps
Min. Breaker Size23.9 amps
Tonnage5 Ton
Height34.5"
Width21"
Depth28.75"
ResourcesGoodman Brochure Goodman Installation Instructions Goodman Parts Manual Goodman Service Manual Goodman Specifications Goodman Technical Information Goodman User Information Goodman 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.
ConfigurationDownflow/Horizontal
Liquid Line3/8"
Suction Line1 1/8"
StyleA-Coil
AHRI Certificate Number7424272
Airflow DirectionDownflow/Horizontal
Exhaust Flue RequirementPlastic / PVC
Product FeaturesRebate Available
Furnace Efficiency / AFUE97%
Blower MotorVariable Speed - ECM
Maximum CFM2000
Burner StagesModulating
Fuel TypePropane, Natural Gas
Suction Line Insulation Thickness1/2"
Length50 feet

Frequently Asked Questions

What's the actual cooling capacity, 4 ton or 5 ton? +
The product title claims 4 tons, but specifications show 5 ton tonnage with 45,500 BTU cooling output (approximately 3.8 tons). Verify with Online Supply before purchase, as this discrepancy affects system sizing and energy calculations. AHRI Certificate 7424272 may clarify rated capacity.
Can I install this in an attic with upflow ductwork? +
No. This is specifically a downflow unit designed for horizontal or downward airflow. Upflow applications require different A-coil orientation and blower configuration. Installing wrongly causes poor distribution and venting problems. Confirm ductwork direction before ordering.
How much will this save on heating bills versus my old furnace? +
At 97% AFUE versus 80% efficiency furnaces, expect 17% lower heating costs with similar usage. A $150 monthly winter bill drops roughly $25. Savings vary by climate, gas rates, and thermostat settings. Modulating burner amplifies savings in mild shoulder seasons through part-load operation.
Is Goodman reliable compared to Lennox or Carrier? +
Goodman uses proven components like scroll compressors and variable-speed motors matching industry standards. Reliability depends more on installation quality and maintenance than brand. Field data shows similar failure rates, though Goodman costs 15-20% less. Warranty duration favors premium brands slightly.
What does the 10-year warranty actually cover? +
Parts coverage includes compressor, heat exchanger, and most components. Labor is excluded. Registration is mandatory within 60 days. Coverage excludes wear items like capacitors and thermostats. Read the full Goodman warranty document before relying on coverage.

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