Tempstar Low Pressure Switch Assembly for T4H548GKD100 — OEM 1177594 | Ships Today
OEM Guaranteed
Same-Day Ship
30-Day Returns
Secure Checkout
Overview
This genuine OEM low pressure switch assembly (part number 1177594) protects the Tempstar T4H548GKD100 compressor from operating under dangerously low refrigerant pressure. Wired into the 24V control circuit, the switch opens when suction-side pressure drops below its setpoint — typically caused by low refrigerant charge, a leak, or restricted airflow — and shuts the compressor down before it is damaged. A low pressure switch that fails open will prevent the compressor from running at all, while a stuck-closed switch removes the safety protection entirely. This assembly includes the switch and its factory connector for a direct plug-in replacement.
Specifications
| Spec | Value |
|---|---|
| Part Number | 1177594 |
| Type | Low Pressure Switch Assembly |
| Brand | Tempstar |
| Control Voltage | 24V |
| Circuit | Normally Closed Safety |
| Application | Heat Pump / Compressor Protection |
| Fitment | OEM Direct Replacement |
Compatibility
Direct OEM fit for the Tempstar T4H548GKD100 heat pump and other ICP-family outdoor units (Heil, Comfortmaker) using the same refrigerant-circuit safety. Verify the part number 1177594 on your existing switch before ordering.
Installation Guide
- Safety First — Disconnect power at the disconnect and breaker, and confirm zero voltage with a multimeter.
- Access — Remove the outdoor unit's service panel to reach the control wiring and refrigerant line.
- Document — Photograph the wiring connections before disconnecting.
- Remove — Unplug the switch leads. The switch is typically a quick-connect Schrader-style fitting; relieve pressure as required and remove the old switch.
- Install — Thread on the new 1177594 switch, confirm a leak-free seal, and reconnect the leads per your photos.
- Test — Restore power and verify the compressor energizes and that the switch holds the circuit closed at normal operating pressure.
Signs You Need a Replacement
- Compressor won't start even with adequate refrigerant charge
- Intermittent compressor lockouts on a low-pressure fault code
- System runs without low-pressure protection after a known fault
- Corroded, cracked, or leaking switch body or fitting
Shipping & Returns
Ships same day on orders placed before 3 PM CST. 30-day returns on unused parts. Backed by the National HVAC Parts fitment guarantee.
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