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Goodman

OEM Goodman Piston Kit for GMP125-4 Furnace — B1789882

SKU: GOODMAN-11911 Brand: Goodman
$16.95 $22.95

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Texas CMBL #19328542014
SAM.gov Registered
Govt POs Accepted

The Goodman B1789882 Piston Kit is a genuine OEM metering device (fixed-orifice restrictor) supplied for Goodman GMP125-4 series equipment. The piston meters refrigerant into the coil at the precise rate the system was engineered for — the correct orifice is essential for rated capacity and efficiency.

Specifications

  • OEM Part #: B1789882
  • Part Type: Piston / fixed-orifice metering kit
  • Application: Goodman GMP125-4 series
  • Includes: Piston(s) as packaged by Goodman
  • Brand: Goodman (OEM)

OEM vs. Generic

Piston bore size is model-specific. An OEM B1789882 guarantees the exact orifice diameter matched to the coil, protecting superheat, subcooling, and capacity. A mismatched aftermarket piston can cause flooding, starving, or a compressor that never reaches rated performance — the small savings are not worth the risk.

Installation Difficulty

Advanced — the refrigerant circuit must be recovered, opened, and evacuated. This is EPA Section 608 work and should be performed only by a certified technician. Recover refrigerant properly; do not vent.

Verify the required piston bore against the equipment charging chart before installing.

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

Frequently Asked Questions

Does this Piston Kit fit my Goodman GMP125-4 Furnace — B1789882?
Yes. This is the factory-specified OEM piston kit for the Goodman GMP125-4 Furnace — 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 GMP125-4 Furnace — 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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Mike Rivera
HVAC Parts Specialist — Online