Furnace runs but does not produce enough heat; home never reaches set temperature

Safety first: Gas pressure and combustion adjustments must be performed by a licensed technician. Homeowners should limit work to cleaning and airflow checks.

• Check filter and vents: Replace dirty filters and open all supply and return registers to ensure proper airflow across the heat exchanger.
• Inspect burners: With power and gas off, remove the burner assembly if accessible. Clean dust and debris from burner ports with a soft brush and compressed air. Reinstall correctly.
• Check thermostat location: Ensure the thermostat is not located near drafts, heat sources, or in direct sunlight, which can cause premature cycle termination.
• Professional checks: Have a technician verify manifold gas pressure, temperature rise across the furnace, and duct static pressure against Napoleon specifications. They can adjust gas valve and blower speed as needed.