What are the specs for this Piston Kit?

The correct replacement for Goodman model GMP125-5 — B1789882 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 GMP125-5 — B1789882.

What symptoms indicate I need a new piston kit?

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

Is this piston kit 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 Piston / Orifice Kit for GMP125-5 — B1789882

Name: OEM Goodman Piston / Orifice Kit for GMP125-5 — B1789882
Brand: Goodman
SKU: GOODMAN-11919
Price: 12.95 USD
Availability: InStock

SKU: GOODMAN-11919 Brand: Goodman

$12.95 $16.95

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Genuine Goodman B1789882 Piston Kit

The Goodman B1789882 is an OEM piston (fixed-orifice) kit designed for the Goodman GMP125-5 platform and compatible Goodman/Amana equipment. The piston is the refrigerant metering device that controls flow into the evaporator coil, setting the system's superheat and cooling capacity. Installing the factory-specified piston is essential to hitting rated performance and protecting the compressor from flooding or starvation.

Specifications

OEM Part Number: B1789882
Type: Piston / fixed-orifice metering device kit
Function: Meters refrigerant flow into the evaporator coil
Bore: Precision-drilled to Goodman factory spec
Compatible Model: Goodman GMP125-5 (and select Goodman/Amana systems)

OEM vs. Generic

Piston bore diameter is matched to tonnage and refrigerant charge. The OEM B1789882 is drilled to the exact size Goodman engineered for this system, so superheat and subcooling land in spec. A wrong-bore generic piston degrades efficiency, causes coil freeze-ups or high head pressure, and can shorten compressor life. Always match the OEM part or the manufacturer's charging chart.

Install Difficulty

Advanced (4/5) — Requires recovering the refrigerant charge, opening the liquid-line connection, swapping the piston in the distributor, and evacuating/recharging the system. This is EPA Section 608 refrigerant work and should be performed by a certified HVAC technician.

Do not attempt without proper recovery equipment and certification.

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 Piston / Orifice Kit...

$12.95

Frequently Asked Questions

Does this Piston Kit fit my Goodman GMP125-5 — B1789882?

Yes. This is the factory-specified OEM piston kit for the Goodman GMP125-5 — B1789882. 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 piston kit on my Goodman GMP125-5 — B1789882?

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 piston kit?

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

Is this piston kit 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 piston kit?

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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