7 Common Furnace Problems & How to Troubleshoot Them

Are you experiencing furnace problems? Furnaces are essential for keeping homes warm and comfortable during colder months, but like any appliance, they can experience issues that hinder their performance. 

At Madd Air Heating & Cooling, we understand how frustrating a malfunctioning furnace can be, especially when temperatures drop. In this article, we explore the most common furnace problems homeowners face and provide practical troubleshooting tips to help you restore your system’s efficiency.

DIY Furnace Repair & Furnace Troubleshooting Tips 

Troubleshooting furnace issues yourself and performing maintenance can save time and money, but it’s essential to approach these tasks safely and with basic knowledge – 

Start by checking the thermostat to ensure it’s set to “heat” and the temperature is higher than the room’s current temperature. Replace the batteries if needed. Next, inspect the air filter; a dirty filter can restrict airflow, causing overheating or inadequate heating. Verify that the furnace is receiving power by checking the circuit breaker and ensuring the power switch is on. If the pilot light is out or the ignition isn’t working, consult your owner’s manual to safely relight it. Clear any obstructions around vents and registers to improve airflow. 

Now that we’ve cleared up the basics, let’s dive into some of the most common furnace issues people experience and provide specific troubleshooting tips for each scenario –

1. Your Furnace Won’t Turn On

Common Causes for a furnace not working:

• Thermostat Issues: The furnace thermostat may be improperly set or malfunctioning.
• Power Problems: A tripped circuit breaker or a blown fuse might cut power to your furnace.
• Pilot Light or Ignition Issues: For older models, the pilot light may be out. Newer models may have a furnace ignition problem.

Furnace Troubleshooting Steps:

• Check the Thermostat: Ensure the thermostat is properly set and powered.
• Inspect Power Sources: Check the breaker box and reset any tripped breakers. Confirm the furnace’s power switch is in the “on” position.
• Relight the Furnace Pilot Light: For furnaces with a standing pilot, follow the manufacturer’s instructions to safely relight it. If the furnace pilot won’t stay lit, contact an HVAC professional.

2. Furnace Blowing Cold Air or Inadequate Heat Production 

The Most Common Causes for a Heater Blowing Cold Air:

• Dirty Air Filters: Blocked filters restrict airflow, reducing heating efficiency.
• Thermostat Calibration: A miscalibrated thermostat may not accurately control the furnace.
• Ductwork Leaks: Leaks in your ducts allow warm air to escape before reaching your living spaces.

Furnace Troubleshooting Steps:

• Replace the Air Filter: Check your filter monthly and replace it every 1-3 months, depending on usage and filter type.
• Test the Thermostat: Ensure it’s properly calibrated. If in doubt, consult an HVAC technician.
• Inspect Ductwork: Look for visible damage or leaks in accessible areas. Seal minor gaps with duct tape, but contact professionals for extensive ductwork repairs or replacement.

3. Frequent Cycling (Furnace Keeps Turning On and Off)

Common Causes:

• Dirty or Clogged Filters: Again, restricted airflow can cause the furnace to overheat and shut off prematurely.
• Oversized Furnace: If your furnace is too large for your home, it may heat the space too quickly and shut off frequently.
• Thermostat Location: A thermostat placed near a heat source may cause the system to cycle unnecessarily.

Furnace Troubleshooting Steps:

• Clean or Replace Filters: Ensure proper airflow by maintaining clean and clear airways.
• Check Thermostat Placement: If possible, relocate the thermostat to a central area away from direct sunlight or vents.
• Consult a Professional: If the furnace is oversized, it may require an adjustment or furnace replacement to improve energy efficiency.

4. Unusual Noises Coming From the Furnace 

Common Causes of Noisy Operation:

• Banging or Popping Sounds: This may indicate ductwork issues (like expanding/contracting ducts) or possibly even furnace ignition delays.
• Squealing or Whining: Often caused by a worn-out blower belt or motor bearings.
• Rattling: Loose components inside the furnace.

Furnace Troubleshooting Steps:

• Tighten Loose Parts: Inspect accessible parts and tighten any loose screws or panels.
• Lubricate Motor Bearings: If you’re familiar with your furnace’s motor, lubricate the bearings to reduce squealing.
• Call a Professional: Persistent noises may indicate deeper mechanical issues requiring professional furnace repairs or furnace maintenance.

5. Poor Airflow & Heat Distribution

Common Causes of Poor Heating & Airflow Problems:

• Clogged Filters: Blockages in the filter impede airflow.
• Furnace Blower Motor Problems: A malfunctioning blower motor may fail to circulate air effectively.
• Blocked Vents or Registers: Obstructions like furniture or debris may block airflow from vents.

Furnace Troubleshooting Steps:

• Inspect Filters: Replace clogged filters to ensure unrestricted airflow.
• Check Vents and Registers: Clear any obstructions and ensure all registers are open.
• Test the Furnace Blower Motor: If the problem persists, have a professional inspect and repair the blower motor.

6. Burning Smell Coming From the Furnace 

Common Causes:

• Dust Burning Off: This is common when you first turn on the furnace for the season.
• Overheating Components: Electrical or mechanical parts overheating can produce a burning smell.
• Clogged Filter: An overheated system due to restricted airflow.

Furnace Troubleshooting Steps:

• Allow Initial Use: If the smell is mild and temporary, it’s likely just dust burning off.
• Turn Off the Furnace: If the burning smell coming from your furnace persists or worsens, turn off the heating system and inspect the filter and electrical components.
• Contact a Professional: Overheating components can be hazardous and should be handled by experts.

7. Furnace Blowing Cold Air

Common Reasons Furnaces Blow Cold Air:

• Thermostat Setting: The thermostat fan setting may be set to “on” instead of “auto.”
• Pilot Light or Ignition Problems: The furnace may fail to ignite properly.
• Dirty Flame Sensor: A dirty sensor may prevent the burners from staying lit.

Furnace Troubleshooting Steps:

• Adjust the Fan Setting: Switch the fan to “auto,” so it only runs during heating cycles.
• Inspect the Pilot Light or Ignition System: If you’re comfortable, clean or replace the flame sensor as needed.

When to Schedule Professional Heating Services

While many furnace issues can be resolved with basic troubleshooting, some require the expertise of a professional HVAC technician. At Madd Air Heating & Cooling, we specialize in diagnosing and repairing furnace problems quickly and efficiently. If your furnace is still malfunctioning after trying these tips—or if you’re unsure about performing any furnace maintenance tasks—don’t hesitate to contact us.

Stay Warm with Madd Air Heating & Cooling

Keeping your furnace in good working order is key to a warm and comfortable home. By addressing common furnace problems promptly, you can prevent costly repairs and ensure your system’s longevity.  If you need expert help, our team is ready to provide top-notch heating services guaranteed to keep your home cozy all winter.

Give us a call at 281-354-9600 to schedule professional heating services today!