



Based on customer reports and repair data, this part commonly fixes these issues:
The air traveling through the pressure switch hose will put a negative pressure or vacuum on the switch, causing it to close when the burner has sufficient airflow and allowing the ignition process to continue. If the hose has a hole in it, or is not securely fastened to the switch, the pressure switch may only close intermittently, causing the furnace to start then stop. Inspect the pressure switch hose for any damage and replace if necessary.