Product Name
$0.00
✅ In Stock
🚚 Ships Today
🔒 OEM Certified
🔄 30-Day Return
Same-day dispatch if ordered by 3PM CST
Free shipping on orders $75+
Check compatibility before ordering
IMAGE COMING SOON
OEM Guaranteed
Same-Day Ship
30-Day Returns
Secure Checkout
The Goodman B1789851 Piston Kit is a genuine OEM refrigerant metering device engineered for the Goodman ANZ130181AB heat pump. The fixed-orifice piston controls the rate of refrigerant flow into the coil, setting the superheat and ensuring efficient, reliable heating and cooling. A worn, clogged, or wrong-sized piston leads to poor capacity, coil frosting, and elevated energy costs — replacing it with the factory-matched orifice returns the system to its designed operating point.
This is a genuine Goodman OEM part with a factory-calibrated orifice bore matched to the ANZ130181AB refrigerant charge and coil design. Generic pistons often deviate from the specified bore diameter, throwing off superheat and charge balance. Because metering accuracy depends on an exact bore, OEM is the recommended choice for correct system performance.
Difficulty: Advanced (EPA-certified technician required). Replacing the piston means recovering refrigerant, opening the sealed system at the liquid-line connection, swapping the orifice, evacuating to a deep vacuum, and recharging by weight or subcooling. Refrigerant handling requires EPA 608 certification — this is a professional repair, not a DIY task.