Review
The Goodman 4 Ton Gas Furnace and Air Conditioner System (SKU LS381183850) combines proven technology with solid efficiency ratings at an accessible price point. This downflow unit replaces the GSX16S481 and brings together an 80,000 BTU furnace rated at 97% AFUE with a 45,500 BTU cooling section rated at 16 SEER2. It's positioned as a mid-market offering for contractors and homeowners who want measurable energy improvements without the cost premium of high-end inverter-driven systems.
Performance-wise, the modulating burner stages adjust heating output smoothly across a wide range, reducing temperature swings and keeping the furnace from cycling on and off excessively. The variable-speed ECM blower can deliver up to 1,600 CFM and tapers down during partial-load conditions, cutting electrical draw substantially. Cooling capacity of 45,500 BTU pairs with a scroll compressor and R410A refrigerant, though the single-stage design means full compressor speed even during light cooling days. Together, these components deliver realistic seasonal efficiency without exotic controls.
Pros & Cons
Pros
- 97% AFUE furnace efficiency with modulating burner stages reduces heating waste and provides smooth temperature control
- 16 SEER2 cooling efficiency and Energy Star certification qualify for utility rebates in many areas
- Variable-speed ECM blower motor adjusts CFM up to 1,600 for better comfort and lower operating costs
- Scroll compressor design is proven reliable and easier to service than rotary alternatives
- 10-year warranty with online registration covers parts and labor, standard for Goodman equipment
Cons
- Single-stage cooling means the compressor runs at full capacity even during mild weather, less efficient than two-stage alternatives
- 73 dB noise level is moderately loud for a residential unit, worth considering if the pad is close to bedrooms
- Downflow configuration limits placement options, requires adequate attic or basement space with proper clearance
Who Should Buy
Best For
Contractors and homeowners replacing 10 to 15-year-old systems who prioritize operational efficiency and want reliable, serviceable equipment at a fair price point. This unit works best in homes with existing ductwork suitable for downflow installation and moderate cooling demands.
Consider Alternatives If
Buyers needing two-stage or variable-capacity cooling for hot climates should explore higher-tier Goodman models or competitors like Lennox or Carrier with more granular capacity control.
Installation
Installation requires downflow orientation with at least 34.5 inches of vertical clearance and proper structural support for the 48-pound unit. Electrical service needs 115V single-phase 60 Hz, with breaker sizing between 23.9 and 40 amps. The plastic PVC flue requirement simplifies venting, and pre-installed line sets (3/8 inch liquid, 1 1/8 inch suction with 1/2 inch insulation) connect to the outdoor condenser. Most installations take one day for a qualified technician.
Warranty & Reliability
Goodman backs this system with a 10-year parts warranty when you register online, a standard offering across their residential lineup. Labor coverage is typically 1 year from major retailers like Online Supply. The warranty is transferable to subsequent homeowners if you register the unit, adding value to your home sale. Review the full warranty documents before purchase to confirm coverage terms with your seller.
Specifications
| SKU | LS381183850 |
| Brand/Manufacturer | Online Supply |
| Cooling BTU | 45,500 |
| Heating BTU | 80,000 |
| Refrigerant | R410A |
| Electrical | 115 V. 1 Phase 60 Hz |
| Warranty | 10 Years with Online Registration |
| Decibel Level (dBA) | 73 |
| Weight (in lbs) | 48.000000 |
| Feature | Spec |
| Replaces | GSX16S481 |
| Energy Star | Yes |
| SEER1 (Efficiency) | 16 |
| Condenser Stages | Single Stage |
| Compressor Type | Scroll |
| Liquid Valve Size | 3/8" |
| Suction Valve Size | 7/8" |
| Max Breaker Size | 40 amps |
| Min. Breaker Size | 23.9 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 Specifications Goodman Technical Information Goodman User Information Goodman Warranty You will need Adobe® Acrobat® 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 | Downflow/Horizontal |
| Liquid Line | 3/8" |
| Suction Line | 1 1/8" |
| Style | A-Coil |
| AHRI Certificate Number | 7424271 |
| Airflow Direction | Downflow/Horizontal |
| Exhaust Flue Requirement | Plastic / PVC |
| Product Features | Rebate Available |
| Furnace Efficiency / AFUE | 97% |
| Blower Motor | Variable Speed - ECM |
| Maximum CFM | 1600 |
| Flue Location | Right |
| Burner Stages | Modulating |
| Fuel Type | Propane, Natural Gas |
| Suction Line Insulation Thickness | 1/2" |
| Length | 50 feet |
Frequently Asked Questions
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