Tempstar Low Pressure Switch for T4H336GKE100 — 24V Assembly | Ships Today
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Overview
This genuine OEM low pressure switch assembly (Part No. 1177594) is the loss-of-charge and freeze-protection safety on the Tempstar T4H336GKE100. Wired into the 24V control circuit, it monitors suction-side refrigerant pressure and opens to shut the compressor down if pressure drops too low — a condition caused by a refrigerant leak, low charge, a restricted metering device, or low airflow. By interrupting the compressor call, the switch prevents the compressor from running in a vacuum and being damaged by overheating or liquid migration. A failed switch may trip with a fully charged system, stick open so the compressor never starts, or stick closed and fail to protect the compressor at all.
Specifications
| Spec | Value |
|---|---|
| Part Number | 1177594 |
| Type | Low Pressure Switch Assembly |
| Brand | Tempstar |
| Control Voltage | 24 VAC Circuit |
| Function | Loss-of-Charge / Compressor Protection |
| Fit | OEM Replacement |
Compatibility
Designed for the Tempstar T4H336GKE100 heat pump and matching ICP / Heil / Comfortmaker condensers that use low pressure switch 1177594. Confirm the part number and connection style (Schrader/quick-connect vs. brazed) against your original before ordering.
Installation Guide
- Safety First — Disconnect power at the disconnect and breaker, then verify zero voltage with a multimeter.
- Access — Remove the condenser service panel to reach the switch on the suction line.
- Document — Photograph the two control wires and the switch location before disconnecting.
- Remove — Disconnect the leads; for Schrader-mounted switches simply unthread the switch (the valve core seals the system). For brazed connections, recover refrigerant first.
- Install — Thread on the new switch with a new gasket/seal, then reconnect the control leads per your photo.
- Test — Restore power, call for cooling, and verify the compressor runs and the switch holds closed at normal operating pressure.
Signs You Need a Replacement
- Compressor will not start even with a confirmed full charge.
- Nuisance low-pressure lockouts that clear and return.
- Switch fails a continuity test against measured suction pressure.
- Corroded, cracked, or leaking switch body or fitting.
Shipping & Returns
Ships same day on orders placed before 3 PM CST. 30-day returns. 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