Findings & Work Performed: Found the pressure switch stuck closed before the call for heat. Removed tubing and discovered a blockage in the pressure switch tubing, specifically at the ports on the inducer motor (photo provided). Cleared the blockage and tested the furnace. Noted that the pressure switch intermittently sticks closed, preventing furnace operation—recommend replacing the pressure switch. Performed a full cleaning and inspection: Removed and cleaned condensate tubing. Inspected and cleaned the flame rod. Conducted combustion analysis. Checked temperature rise and verified all safety functions. Inspected heat exchanger. Furnace is currently operating normally. Additional Recommendations: Suggest flushing the Navien tankless water heater for maintenance. Provided humidifier installation cost estimate.