3.5 Ton 14 SEER 80% AFUE 100,000 BTU Goodman Gas Furnace and Air Conditioner System - Upflow Review 2026

// Bottom Line

This Goodman system suits contractors and homeowners seeking reliable, affordable cooling and heating without premium pricing or ENERGY STAR certification. The 14 SEER rating and 80% AFUE deliver respectable efficiency gains over older units, making it practical for budget-conscious replacements in moderate climates.

Review

The Goodman 3.5 ton combo system represents mainstream HVAC equipment designed for contractors and homeowners seeking reliable performance at accessible price points. This unit pairs a 42,000 BTU air conditioner with a 100,000 BTU furnace, delivering both cooling and heating from a single integrated package. The upflow A-coil configuration suits typical residential installations where space above or beside the furnace accommodates the condenser unit.

Performance specifications show a 14 SEER cooling rating and 80% AFUE heating efficiency, positioning this system solidly in the mid-range segment. The variable-speed blower motor and two-stage burner provide measurable comfort improvements over single-stage equipment. With a scroll compressor, 120V single-phase power requirement, and 22-35 amp breaker sizing, installation fits standard residential electrical service. Maximum CFM of 2,000 handles the 3.5 ton capacity appropriately for homes under 2,500 square feet.

Pros & Cons

Pros

Variable-speed blower motor optimizes comfort and reduces energy waste during partial-load operation
Two-stage burner provides better temperature modulation than single-stage alternatives
14 SEER cooling efficiency exceeds baseline standards by meaningful margin
Scroll compressor is durable workhorse technology with strong field reliability records
Metal exhaust flue requirement keeps installation straightforward without special venting materials

Cons

80% AFUE furnace efficiency lags behind 95%+ high-efficiency models, increasing heating costs
No ENERGY STAR certification means missing potential utility rebates in many regions
Single-stage condenser limits cooling modulation compared to two-stage designs
73 dB noise level is audible and noticeable during peak operation

Who Should Buy

Best For

Contractors installing replacement systems in residential homes where budget constraints limit premium options, and homeowners seeking reliable performance without paying for high-efficiency extras. This system makes sense in moderate climates where heating seasons are shorter and rebates aren't available.

Consider Alternatives If

Buyers in cold climates where an 80% AFUE furnace will cost significantly more to operate, or those prioritizing maximum efficiency and willing to invest more upfront for ENERGY STAR and variable-stage cooling.

3.5 Ton 14 SEER 80% AFUE 100,000 BTU Goodman Gas F

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Installation

Installation requires standard residential electrical service with adequate breaker capacity between 22-35 amps. The A-coil fits upflow or horizontal orientation, providing flexibility for basement or attic placement. Suction line insulation measures 3/8 inch thickness, meeting code requirements. Metal exhaust flue is mandatory for safe gas venting. Line set connections use 3/8 inch liquid and 7/8 inch suction valves with pre-insulated suction line up to 30 feet, simplifying field work.

Warranty & Reliability

Goodman backs this system with a 10-year comprehensive warranty when you complete online registration, covering parts and compressor defects. This warranty is standard for mid-tier equipment and provides reasonable protection for residential buyers. Registration is mandatory to activate coverage, so documentation should be kept accessible. Warranty doesn't cover installation labor or refrigerant, following industry norms.

Specifications

SKU	LS38783830
Brand/Manufacturer	Online Supply
Cooling BTU	42,000
Heating BTU	100,000
Refrigerant	R410A
Electrical	120 V. 1 Phase 60 Hz
Warranty	10 Years with Online Registration
Decibel Level (dBA)	73
Weight (in lbs)	30.000000
Feature	Spec
Energy Star	No
SEER1 (Efficiency)	14
Condenser Stages	Single Stage
Compressor Type	Scroll
Liquid Valve Size	3/8"
Suction Valve Size	7/8"
Max Breaker Size	35 amps
Min. Breaker Size	22 amps
Tonnage	5 Ton
Height	34.5"
Width	21"
Depth	28.75"
Resources	Goodman Brochure Goodman Installation Instructions Goodman Parts Manual Goodman Service Manual Goodman Technical Information Goodman User Information Goodman Warranty You will need AdobeÂ® AcrobatÂ® Reader to view PDF documents.
Safety Information	PROPOSITION 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.
Configuration	Upflow/Horizontal
Liquid Line	3/8"
Suction Line	7/8"
Style	A-Coil
Airflow Direction	Upflow/Horizontal
Exhaust Flue Requirement	Metal
Furnace Efficiency / AFUE	80%
Blower Motor	Variable Speed
Maximum CFM	2000
Burner Stages	Two
Fuel Type	Propane, Natural Gas
Suction Line Insulation Thickness	3/8"
Length	30 feet

Frequently Asked Questions

What's the actual difference between 14 SEER and higher ratings like 16 or 18? +

Each SEER point represents approximately 3-5% annual cooling efficiency improvement. A 16 SEER unit costs 15-20% more but saves roughly 12-18% on summer electricity over this 14 SEER model. In moderate climates, payback takes 8-12 years, making higher SEER worth considering if you plan long-term occupancy.

Will this system work with my existing ductwork and thermostat? +

The 2,000 CFM maximum airflow fits standard residential ductwork designed for 3.5-ton systems. Your existing thermostat must support variable-speed blower motors, which most modern units do. Have an HVAC technician verify duct sizing and static pressure before installation to ensure proper operation.

How does 80% AFUE compare to high-efficiency furnaces? +

An 80% AFUE furnace converts only 80 cents per heating dollar into usable warmth, losing 20% through the exhaust flue. High-efficiency models reach 95%+ AFUE with condensing technology. In cold climates heating 6-7 months yearly, upgrading to 95% AFUE costs 25-30% more but recovers investment through fuel savings over 12-15 years.

Should I choose this or a single-stage unit instead? +

This system's two-stage burner and variable-speed blower provide superior comfort by reducing on-off cycling and temperature swings. Single-stage equipment is noisier, less efficient, and less comfortable. The upgrade cost typically runs 8-12% more but justifies itself through lower utility bills and quieter operation over the system's 15-20 year lifespan.

What does the 10-year warranty actually cover? +

Goodman's warranty covers defective parts and compressor failure when you register within 30 days. Labor is not covered. Warranty is voided if system is installed improperly or used with non-compatible components. Keep documentation for all service calls to protect coverage eligibility throughout the term.

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