Goodman - 40,000 BTU 80% Gas Furnace - 14" Width - Upflow / Horizontal - Single Stage - 115V - R32 - GR9S800403AX

Goodman - 40,000 BTU 80% Gas Furnace - 14" Width - Upflow / Horizontal - Single Stage - 115V - R32 - GR9S800403AX

The GRS800403AX Goodman low NOx gas furnace features high-quality construction and efficient operation at a great value. The GR9S800403AX single-stage, 9-speed furnace utilizes Goodman's superior heat exchanger design to provide efficient, reliable heating to your home. If you're looking to cut your energy bills and improve your comfort without breaking the bank, your search stops with the Goodman GR9S800403AX.

Features

• This furnace is ideal to heat a smaller house (depending on climate)
• 40,000 BTU 80% efficient natural gas furnace
• Requires metal flue venting
• Can be used in the upflow or horizontal (right or left) orientation
• Can be converted to an LP furnace with a conversion kit (sold separately)
• Innovative design for electrical efficiency, safety, and lower sound output
  

Specifications

Manual

• Installation Manual
• Specifications Sheet
  

What our Experts Think

• Efficient & Compact Heating Solution
  The Goodman GR9S800403AX is a 40,000 BTU, 80 % AFUE single‑stage gas furnace designed for efficient heat delivery in smaller homes or spaces, converting most fuel into usable warmth with steady performance.

• Modern R‑32 Compliant Design
  Built to meet R‑32 refrigerant system compatibility, this furnace supports current HVAC configurations and complies with Low‑NOx emissions standards, helping reduce environmental impact where required.

• Reliable, Simple Operation
  The single‑stage gas valve ensures consistent heat output whenever called, offering straightforward, dependable winter comfort without the complexity of modulation.

• Quiet & Efficient Airflow
  A 9‑speed ECM blower motor improves airflow control and energy use compared with traditional motors, delivering quiet, smoother comfort distribution throughout living spaces.

• Durable Construction & Diagnostics
  Features like a heavy‑duty aluminized‑steel tubular heat exchanger, durable hot‑surface igniter, and self‑diagnostic control board support long‑term reliability and easier servicing.

• Versatile Installation
  Its 14″ width and upflow/horizontal configuration fit in compact spaces such as attics, closets, or crawl spaces—great for tight installation environments.

Q&A

Q1: What size and efficiency does this furnace deliver?
A: The Goodman GR9S800403AX provides 40,000 BTU input heating with 80% AFUE, meaning most fuel is efficiently turned into heat for your home.

Q2: What operation type and stages does it use?
A: It’s a single‑stage gas furnace with a straightforward on/off heating cycle for reliable performance.

Q3: Which installation orientations are supported?
A: Supports both upflow and horizontal installations, giving flexibility for attic, crawl space, or closet placement.

Q4: What blower and motor features are included?
A: Includes a multi‑speed ECM blower motor (up to ~1,200 CFM) for quieter operation and smoother airflow control.

Q5: What are the electrical requirements?
A: Operates on 115 V single‑phase 60 Hz with typical breaker sizing around 15 A.

Q6: What fuel and venting are required?
A: Runs on natural gas (convertible to propane with a kit) and requires metal flue venting typical of 80% AFUE furnaces.

Q7: What are the physical dimensions?
A: Cabinet measures about 14″ wide × 33 3/8″ high × 28″ deep, ideal for compact installation spaces.

Maintenance Tips

• Change Air Filters Every 1–3 Months – Ensures proper airflow, protects the blower motor, and improves heating efficiency.

• Annual Heat Exchanger & Burner Inspection – Have a technician check for cracks, corrosion, or soot buildup to ensure safe combustion and maintain 80% AFUE performance.

• Clean Condensate Drain & Pan – Clear any blockages to prevent water buildup and microbial growth.

• Check Electrical & Control Components – Inspect wiring, limit switches, and thermostat connections for wear or loose contacts.

• Keep Vents & Returns Unobstructed – Maintain clear supply and return air paths to prevent overheating and maintain efficiency.

• Schedule Professional Annual Service – A qualified HVAC tech should test safety controls, check gas pressure, verify ignition, and optimize system performance.