ICP Pressure Switch for WPG4304040RKA1 — Tubing Air Pressure Switch | Ships Today
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Overview
This OEM air pressure switch with tubing (part 1178417) is the draft-proving safety control for the ICP / Tempstar / Heil WPG4304040RKA1 gas package unit. When the inducer (draft) motor starts, it creates negative pressure that this switch senses through its tubing; only when adequate draft is confirmed does the switch close and allow the control board to energize the igniter and open the gas valve. This prevents the burners from firing without proper venting — a critical safety function. A stuck-open switch, blocked tubing, or a weak diaphragm will keep the furnace from igniting, while a stuck-closed switch defeats the safety interlock entirely. Replacing it with the correct OEM switch restores safe, reliable ignition sequencing.
Specifications
| Spec | Value |
|---|---|
| Part Number | 1178417 |
| Type | Air Pressure Switch with Tubing |
| Brand | ICP / Tempstar / Heil |
| Function | Combustion draft proving |
| Application | Gas furnace / package unit |
Compatibility
Supplied as the factory draft-switch replacement for the ICP WPG4304040RKA1 packaged gas unit and shared across comparable ICP, Tempstar, Heil, and Comfortmaker models. Pressure switches are calibrated to a specific trip point — match the part number and rating to your original before installing.
Installation Guide
- Safety First — Shut off gas and disconnect power, then verify zero voltage with a multimeter.
- Access — Remove the service panel to reach the inducer and pressure switch.
- Document — Photograph the tubing routing and electrical connections before removal.
- Remove — Disconnect the tubing and wires, then unscrew the switch from its bracket.
- Install — Mount the new switch, reattach the tubing with no kinks, and reconnect the wires per your photo.
- Test — Restore gas and power, start a heat cycle, and confirm the switch closes and the burners light.
Signs You Need a Replacement
- Furnace inducer runs but burners never ignite.
- Control board flashes a pressure-switch / draft fault code.
- Switch fails to close on adequate draft, or stays closed at rest.
- Short-cycling or repeated ignition lockouts.
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