Tempstar Low Pressure Switch for T4H548GKD200 — OEM Assembly 24V | Ships Today

Overview

This OEM low pressure switch assembly (part #1177594) is a refrigerant-side safety control on your Tempstar T4H548GKD200. Wired into the 24V control circuit, it opens when suction-side refrigerant pressure drops below a safe threshold — protecting the compressor from running on a low or lost charge, a blocked line, or a frozen coil. When the switch trips or fails, the compressor will be locked out or short-cycle, and the system won't cool or heat properly.

Specifications

Compatibility

Direct OEM fit for the Tempstar T4H548GKD200 heat pump. Also used across ICP-family (Heil, Comfortmaker, Tempstar) condensing units and heat pumps that specify low pressure switch assembly #1177594. Match the part number and connection type on your existing switch before ordering.

Installation Guide

1. Safety First — Disconnect power at the disconnect and breaker, then verify zero voltage with a multimeter. Note this part is on the sealed refrigerant circuit.
2. Access — Remove the outdoor unit's service panel to reach the switch and its leads.
3. Document — Photograph the wiring and mounting location before disconnecting.
4. Remove — Disconnect the 24V leads; if the switch threads onto a Schrader-style port it can be swapped without recovery, otherwise recover refrigerant first.
5. Install — Mount the new switch assembly and reconnect the control leads per your photo.
6. Test — Restore power, confirm the switch is closed at normal pressure, and verify the compressor runs and the safety functions.

Signs You Need a Replacement

• Compressor won't start or is locked out on a low-pressure fault.
• System short-cycles even with a verified good refrigerant charge.
• Switch fails a continuity test at normal operating pressure.
• Nuisance trips that clear when the switch is jumpered.

Shipping & Returns

Ships same day before 3 PM CST. 30-day returns. Backed by the National HVAC Parts fitment guarantee.