What are the specs for this Heat Exchanger?

The correct replacement for Goodman model GMNT120-5B — 4821404S is this exact part. It is the factory-specified replacement with exact OEM specifications. Using a part with different specifications can cause equipment damage or void your warranty. You can verify this by checking the data plate on your Goodman equipment which lists the model number GMNT120-5B — 4821404S.

What symptoms indicate I need a new heat exchanger?

Common symptoms that indicate you need a new heat exchanger include unusual noises, intermittent operation, complete failure to operate, or visible damage. For specific diagnostic guidance, visit nationalhvacparts.com/pages/hvac-diagnostic.

Is this heat exchanger compatible with Bryant or Payne systems too?

Many Goodman parts are cross-compatible with Bryant and Payne systems since all three brands are manufactured by Carrier Global Corporation. The same physical part is often used across multiple brand labels with different model numbers. To verify cross-compatibility, check your Bryant or Payne equipment service manual for cross-compatible part numbers, or contact info@nationalhvacparts.com with your model number for confirmation.

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Goodman

OEM Goodman 24-1/2 in 6-Cell Heat Exchanger for GMNT120-5B — 4821404S

Name: OEM Goodman 24-1/2 in 6-Cell Heat Exchanger for GMNT120-5B — 4821404S
Brand: Goodman
SKU: GOODMAN-11755
Price: 433.95 USD
Availability: InStock

SKU: GOODMAN-11755 Brand: Goodman

$433.95 $563.95

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Goodman 4821404S 6-Cell Heat Exchanger

The Goodman 4821404S is a genuine OEM 24-1/2 inch, 6-cell heat exchanger engineered as a direct-fit replacement for the GMNT120-5B gas furnace. The heat exchanger is the heart of your furnace's combustion system — it transfers heat from burning gas to the circulating air while safely containing exhaust gases. A cracked or corroded heat exchanger is a common cause of failed inspections, carbon-monoxide concerns, and no-heat callbacks, making this one of the most critical components to replace with a factory-spec part.

Specifications

Overall size: 24-1/2 inch
Configuration: 6-cell clamshell design
Material: aluminized/stainless steel construction
Fits: Goodman GMNT120-5B furnace (120,000 BTU class)
OEM part number: 4821404S
Equipment type: gas furnace

OEM vs. Generic

This is a genuine OEM Goodman heat exchanger, not an aftermarket universal. Because heat exchangers must precisely match burner spacing, cell geometry, and airflow, we do not recommend generic substitutes for this component. The OEM part guarantees correct combustion clearances, warranty compliance, and long-term corrosion resistance. Generic weld-up exchangers can shift flame patterns and shorten furnace life.

Installation Difficulty

Advanced (4/5). Replacing a heat exchanger requires disassembling the furnace burner box, disconnecting gas and electrical, and recalibrating combustion. This repair should be performed by a licensed HVAC technician, followed by a combustion analysis and CO test before returning the unit to service.

Fits Goodman GMNT120-5B. Verify your model and cell count before ordering.

Shipping Information

Orders placed before 3PM CST ship same business day
Standard delivery: 2-5 business days
Express shipping available at checkout
Free shipping on orders over $75
Tracking number emailed upon shipment

Return Policy

30-day returns on unused parts in original packaging
Electrical parts (capacitors, contactors, control boards) are final sale once installed
Email info@nationalhvacparts.com to initiate a return
Refunds processed within 5-7 business days

OEM Goodman 24-1/2 in 6-Cell Hea...

$433.95

Frequently Asked Questions

Does this Heat Exchanger fit my Goodman GMNT120-5B — 4821404S?

Yes. This is the factory-specified OEM heat exchanger for the Goodman GMNT120-5B — 4821404S. It is a direct drop-in replacement that fits without modification. Always verify the model number on your equipment nameplate before ordering.

How do I replace the heat exchanger on my Goodman GMNT120-5B — 4821404S?

Refer to your equipment service manual for model-specific steps. General approach: turn off power, photograph connections, remove old part, install new part, restore power and test. For gas components, hire a licensed technician. Email info@nationalhvacparts.com for guidance.

What symptoms mean I need a new heat exchanger?

Common symptoms: unusual noises, intermittent operation, complete failure, or visible damage. Visit our diagnostic hub for symptom-based troubleshooting.

Is this heat exchanger compatible with Bryant or Payne too?

Many Goodman parts are cross-compatible with Bryant and Payne since all three brands are manufactured by Carrier Global Corporation. The same physical part is often used across brand labels with different model numbers. To verify: check your Bryant or Payne equipment service manual for cross-compatible part numbers, or email info@nationalhvacparts.com with your model number.

Should I use OEM or aftermarket for my Goodman heat exchanger?

OEM recommended for reliability and warranty compatibility. OEM parts match exact factory specifications for proper fit, performance, and safety. While aftermarket alternatives cost less upfront, the risk of improper fit and reduced lifespan usually makes OEM the better value long-term.

How fast does National HVAC Parts ship?

Orders placed before 3:00 PM CST ship the same business day. Standard delivery is 2–5 business days anywhere in the continental United States. Express shipping available at checkout. We ship from Houston, TX to all 50 states. 30-day return policy on all parts.

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