Dirty or clogged filters: Dirty filters restrict airflow, reducing efficiency and causing the furnace to work harder than necessary.

Worn-out or malfunctioning parts: Components such as belts, bearings, ignition systems, and motors can wear out over time and may need replacement.

Lack of lubrication: Moving parts within the furnace require proper lubrication to function smoothly. Lack of lubrication can lead to increased friction and premature wear.

Pilot light or ignition problems: Issues with the pilot light or ignition system can prevent the furnace from starting or cause it to intermittently shut off.

Thermostat problems: Malfunctioning thermostats can lead to inaccurate temperature readings or difficulty maintaining desired temperatures.

Blocked vents or ductwork: Obstructions in the vents or ductwork can restrict airflow and reduce heating efficiency.

Gas leaks: Gas furnaces can develop leaks in the gas supply line or connections, posing a safety hazard and affecting performance.

Electrical issues: Wiring problems, loose connections, or faulty electrical components can cause the furnace to malfunction or fail to operate altogether.

Dirty burners: Dirt, dust, or debris buildup on the burners can affect combustion efficiency and lead to incomplete burning of fuel.

Improper sizing: Furnaces that are too large or too small for the space they are heating can lead to inefficiency and uneven heating.

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