ICP Pressure Switch for WPG4604090LKA1 — With Sensing Tubing | Ships Today

Overview

The 1178417 is a genuine OEM pressure switch assembly with tubing for the ICP / Tempstar / Heil WPG4604090LKA1 packaged gas-electric unit. The pressure switch is a safety device that confirms the inducer/draft fan is moving combustion gases properly before the control board allows the igniter and gas valve to fire. It senses negative pressure through the attached tubing; if adequate draft isn't present, it keeps the burners locked out to prevent unsafe operation. A failed switch, or a cracked or blocked tube, is a frequent cause of intermittent no-heat lockouts.

Specifications

Compatibility

Engineered for the ICP WPG4604090LKA1 and shared across many Tempstar, Heil, and Comfortmaker units using the same inducer assembly. Match the switch's pressure set point ("W.C." rating) to your existing part before installing.

Installation Guide

1. Safety First — Shut off gas and disconnect power at the disconnect and breaker, then verify zero voltage with a multimeter.
2. Access — Remove the furnace control/inducer access panel.
3. Document — Photograph the tubing routing and electrical leads before disconnecting.
4. Remove — Pull the sensing tube from the port, disconnect the spade terminals, and unscrew the old switch from its bracket.
5. Install — Mount the new switch, reconnect the leads, and seat the tubing firmly on the port per your photo — keep the tube free of kinks and moisture.
6. Test — Restore gas and power, run a heat cycle, and confirm the inducer starts and the switch proves draft so the burners light.

Signs You Need a Replacement

• Furnace inducer runs but burners never light (lockout)
• Intermittent no-heat that clears and returns
• Control board flashes a pressure-switch fault code
• Cracked, brittle, or moisture-clogged sensing tubing

Shipping & Returns

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