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

Safety First: Gas pressure and combustion adjustments must be done by a qualified technician. Homeowners should limit work to airflow and cleaning tasks.

• Check filter and vents: Replace dirty filters and ensure all supply and return vents are open.
• Inspect burners (visual): Through the sight glass, verify all burners light evenly and fully. Uneven or small flames suggest burner or gas issues.
• Check thermostat calibration: Compare thermostat reading to a separate room thermometer. If off by several degrees, recalibrate or replace the thermostat.
• Schedule professional service: Have a technician check manifold gas pressure, clean burners and heat exchanger, and verify blower speed tap settings on the Thermo Pride control board.