Tempstar Low Pressure Switch Assembly for T4H524GKD100 — Heat Pump | Ships Today

Overview

This is a genuine OEM low pressure switch assembly (part 1177594) for the Tempstar T4H524GKD100 heat pump. The low pressure switch is a safety control wired into the 24V control circuit that monitors refrigerant suction pressure. If pressure drops below a safe threshold — typically from a refrigerant leak, a restriction, or a failed metering device — the switch opens and shuts down the compressor to protect it from running dry. A failed switch, or one that's correctly tripping on a low charge, will prevent the compressor from starting. Symptoms include a compressor that won't run, intermittent lockouts, or a unit that short-cycles on the pressure safety.

Specifications

Compatibility

Designed for the Tempstar T4H524GKD100 and related ICP / Heil / Comfortmaker heat pumps using this low pressure cutout. Verify the OEM part number and pressure rating against your existing switch before ordering.

Installation Guide

1. Safety First — Disconnect power at the disconnect and breaker, verify zero voltage with a multimeter.
2. Access — Remove the service panel to reach the refrigerant line and switch.
3. Document — Photograph the wiring and switch location before disconnecting.
4. Remove — Disconnect the leads; if the switch is on a Schrader-style port, unscrew it (no recovery needed), otherwise recover refrigerant before unbrazing.
5. Install — Thread or braze in the new switch, reconnect the leads per your photo, and confirm the port seals.
6. Test — Restore power, verify proper charge, and confirm the compressor starts and the safety holds closed.

Signs You Need a Replacement

• Compressor won't start / locked out on low pressure
• Switch fails continuity test with adequate charge
• Intermittent short-cycling on the pressure safety
• Physically damaged or leaking switch body

Shipping & Returns

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