The Pentair 42001-0402Z is the OEM replacement 2-inch slip half union for Sta-Rite heaters. If your plumbing connection at the heater requires a half union replacement, this is the factory-matched component for that application.
⚠️ IMPORTANT: HEATER PLUMBING — PROFESSIONAL SERVICE REQUIRED
Gas and electrical heater components must be serviced by a licensed pool professional or qualified HVAC technician. Do not attempt to service gas or high-voltage components without proper certification.
The half union provides a serviceable, leak-free connection point at the heater's plumbing inlet or outlet, allowing the heater to be isolated and removed without cutting the supply line. A worn or cracked half union can result in water leaks at the heater connection — replacing it with the correct OEM part restores a proper seal at the union joint.
Specifications
| Pentair Part Number |
42001-0402Z |
| Also Known As |
42001-0402 (Pentair, formerly Sta-Rite) |
| Connection Size |
2" Slip |
| Part Type |
Half Union |
| Quantity Included |
1 |
Pro Tip
Half unions are sold individually — confirm whether you need one or two (inlet and outlet) before ordering. Match the part number on your existing union body before purchasing. When reassembling, hand-tighten the union nut first to ensure the O-ring seats squarely, then snug with a strap wrench — do not over-torque.
