5 Most Common Furnace Problems

You probably don’t give your furnace much thought – until it fails. The good news is that many furnace problems are easy to correct. While it’s advisable to hire a professional when your furnace isn’t working properly, there are some issues that you may even be able to fix yourself.

1. Clogged or Dirty Filters

Issue: Dirty or clogged air filters restrict airflow, causing your furnace to work harder than it needs to, making it less efficient.

Solution: Regularly check and replace filters every one to three months to keep your furnace in good working order and to ensure maximum efficiency.

2. Wear and Tear on Furnace Parts

Issue: Over time, components such as belts, bearings, and motors can wear out, leading to performance issues.
Solution: Schedule regular heating maintenance to catch problems early and avoid a headache later. This will help to replace any worn-out parts to avoid further damage.

3. Pilot or Ignition Control Issues

Issue: Problems with the ignition or pilot light can lead to issues with the furnace’s ability to start or stay running.
Solution: Check and clean the pilot assembly. Keep in mind that if you’re uncomfortable or unsure of how to do this, it’s always best to consult a professional HVAC technician.

4. Malfunctioning Thermostat

Issue: Incorrect thermostat settings, a dead battery, or a faulty thermostat can result in temperature control problems.
Solution: Verify thermostat settings, replace batteries if applicable, and consider recalibrating or replacing the thermostat if issues persist.

5. Lack of Maintenance

Issue: Neglecting regular maintenance and inspections can make your furnace prone to breakdowns and poor performance. You could also see increased energy costs as a result of failing to maintain your furnace.
Solution: Schedule annual maintenance. Annual checkups can prevent over 70% of all furnace repairs as well as improve your system’s efficiency by up to 16% — saving you money! Sign up for our maintenance program and get complimentary systems checks as well as priority scheduling and member discounts.

Choose Larry & Sons for Furnace Repairs in MD, PA, & WV

Remember that furnace issues can have various causes, and proper diagnosis is crucial. If you encounter problems that you’re unsure how to address, or if issues persist after basic troubleshooting, call the highly qualified heating experts at Larry & Sons. Our technicians can handle all aspects of furnace repair, maintenance, and installation.

Call (301) 733-5428 today to request furnace repair services.  

No Heat? Learn Basic Furnace Troubleshooting Tips

Did your furnace give out? It’s understandable given all of the overtime work it’s been putting in. But before assuming the worst and calling in a professional, learn some basic furnace troubleshooting tips to get your heat running again.

Furnace Troubleshooting Tips

Although we hope that these troubleshooting tips help you get the heat back on, it is extremely important to schedule annual heating and cooling maintenance to prevent breakdowns and ensure your warranty remains in effect. A maintenance plan is recommended to save money and extend the life of your heating and cooling system.

Without further ado,

5 Furnace Troubleshooting Tips

  1. Breaker Box – Check to see if your furnace threw the breaker switch. If you don’t have your breaker panel labeled, now is a good time to do so. After locating the correct breaker switch, simply flip the switch all the way to the “off” position (opposite direction of all the other switches) and then flip it back on (same direction as all the other switches).
  2. Furnace Filter – If your power is on, you should check your furnace’s air filter. Sometimes, your furnace will actually shut itself off if the filter is dirty and clogged enough. This is done as a precautionary measure since an overloaded heat exchanger can be dangerous and lead to costly repairs.
    • If you don’t remember the last time you replaced the filter, then it is probably due for one. To make sure that you remember to check and/or change the furnace filter every 30-90 days, you should set a reminder on your phone or calendar for the first of every month to check the filter.
  3. Blower Panel – Like with the furnace filter, sometimes a furnace won’t turn on as a precautionary measure if the blower panel is ajar. This prevents the blower from turning on while someone is working on the furnace. If your furnace won’t start, make sure the door that houses your blower motor is fully closed.
  4. Thermostat – The next thing you want to check is your thermostat. Make sure that it is set to “heat” and that the thermostat is set above the room temperature. Also, check to see if you need to change the batteries. Here is a good video for learning how to change your thermostat’s batteries if you have never done so before:
  5. Gas Valve & Pilot Light – If the previous steps did not solve your problem, the issue may be with your gas valve or pilot light. The gas valve may have inadvertently been closed or forgotten to be turned back on when someone was working on the furnace. If the gas valve, your furnace won’t have the fuel necessary to run.
    • To locate your gas valve, trace the gas line to your furnace until you see a handle on the pipe. If the handle is perpendicular, turn it until it is parallel with the pipe. Sometimes there will be a separate gas valve located on or around your furnace. Look around to ensure the gas is “on.”
    • Furnace Troubleshooting
    • If you have an older furnace, you should check the pilot light to see if it is lit. If the gas is on, but still no flame, you will want to turn the gas “off” again in order to relight the pilot light. Once the gas is off and all the fumes have disappeared, now it is safe to light the pilot light. Make sure you double check your model’s specific manufacturer instructions, but it is safe to say that you either have an ignitor button or will have to manually light it with a long match or lighter. For most furnaces, this how-to video should do the trick:

Hopefully, these 5 Furnace Troubleshooting Tips were able to solve your heating problem. If not, don’t hesitate to call the HVAC professionals at Larry & Sons.

For furnace installation, repair, & maintenance, Larry & Sons is your trusted heating and cooling service provider in the tri-state area, including Hagerstown, Frederick, and Middletown.

We understand the importance of keeping warm, especially with the weather being as it is. We’ll repair your furnace in a timely manner so that you can get back to enjoying a warm and comfortable home.


If you haven’t already, don’t forget to schedule your annual heating and cooling tune-up! 301-733-5428

With our maintenance plan, we’ll remind you of your annual tune-up, provide 15 % off all repairs, and much more!

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