Tempstar Low Pressure Switch Assembly for T4H442GKD100 — Refrigerant Safety Switch | Ships Today
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Overview
This genuine OEM low pressure switch assembly (part number 1177594) protects the compressor in your Tempstar T4H442GKD100 by monitoring suction-side refrigerant pressure. If pressure drops below the safe threshold — typically from a refrigerant leak, a stuck metering device, or a frozen coil — the switch opens and shuts the compressor down before it can run dry and self-destruct. A failed or stuck switch can cause nuisance no-cool/no-heat lockouts, short cycling, or, worse, fail to protect the compressor during a real loss-of-charge event. Symptoms include the system refusing to start, the compressor cycling on and off rapidly, or a control board reporting a low-pressure fault.
Specifications
| Spec | Value |
|---|---|
| Part Number | 1177594 |
| Type | Low Pressure Switch Assembly |
| Brand | Tempstar (ICP / Heil) |
| Function | Loss-of-charge / low-suction protection |
| Fit | OEM Direct Replacement |
Compatibility
Exact-fit OEM replacement for the Tempstar T4H442GKD100 and related ICP-family (Tempstar, Heil, Comfortmaker) heat pump units that use the 1177594 assembly. Verify the cut-out/cut-in pressure rating and connection style against your existing switch before installing.
Installation Guide
- Safety First — Disconnect power at the disconnect and breaker, then verify zero voltage with a multimeter.
- Access — Remove the control-area service panel to reach the switch and its refrigerant connection.
- Document — Photograph the wire leads and the switch's mounting/port location before disconnecting.
- Remove — Disconnect the wiring, then unthread or unseat the switch from its Schrader/braze port (recover refrigerant if the port is not self-sealing).
- Install — Seat the new switch on the port, confirm a leak-free connection, and reconnect the leads per your photo.
- Test — Restore power, start the system, and confirm normal operation with no low-pressure fault.
Signs You Need a Replacement
- System won't start and the board reports a low-pressure lockout
- Compressor short cycles even with a full refrigerant charge
- Switch stays open (no continuity) at normal operating pressure
- Visible corrosion or damage at the switch body or terminals
Shipping & Returns
Ships same day 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