What are the specs for this Piston Kit?

The correct replacement for Goodman model WGHP4324AAB — B1789857 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 WGHP4324AAB — B1789857.

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 Kit for WGHP4324AAB — B1789857

Name: OEM Goodman Piston Kit for WGHP4324AAB — B1789857
Brand: Goodman
SKU: GOODMAN-891
Price: 10.95 USD
Availability: InStock

SKU: GOODMAN-891 Brand: Goodman

$10.95 $14.78

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Texas CMBL #19328542014

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Govt POs Accepted

The Goodman B1789857 Piston Kit is a genuine OEM metering device built for WGHP4324AAB systems. The fixed-orifice piston (flowrator) controls the rate of liquid refrigerant entering the evaporator or condenser coil, setting the system's superheat and subcooling. A worn, clogged, or incorrectly sized piston causes poor cooling capacity, frost on the coil, or high head pressure.

Specifications

Part Number: B1789857
Part Type: Fixed-orifice Metering Piston (Flowrator)
Compatible Model: WGHP4324AAB
Brand: Goodman
Function: Refrigerant metering / superheat control
Fit: Direct OEM replacement

OEM vs. Generic

The orifice bore on the OEM B1789857 is precision-drilled to a diameter matched to this unit's tonnage. Generic pistons in the wrong bore size will starve or flood the coil. Because metering is so size-sensitive, the OEM-spec piston is the safe choice.

Installation

Difficulty: Advanced (EPA 608 certification required). The piston seats inside the liquid-line connection at the coil; replacement requires refrigerant recovery, evacuation, and recharge. Have a licensed HVAC technician perform the swap.

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 Kit for WGHP4...

$10.95

Frequently Asked Questions

Does this Piston Kit fit my Goodman WGHP4324AAB — B1789857?

Yes. This is the factory-specified OEM piston kit for the Goodman WGHP4324AAB — B1789857. 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 WGHP4324AAB — B1789857?

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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