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Troubleshooting Furnace Problems

There is no good time to have a furnace problem, and it can be especially inconvenient if it happens late at night or over the weekend when you may have to wait longer for service. Though most furnace problems should be handled by a professional HVAC contractor, there are a few things you can do to troubleshoot your furnace and possibly avoid a service call.

Furnace Troubleshooting Tips

Here are some of the most common furnace problems and solutions you can try before calling a professional:

  • Furnace will not start or will not produce any heat. Make sure your thermostat is set correctly, and check your electrical panel to see if the furnace breakers have tripped. If your furnace still will not operate, make sure the pilot light is on, if equipped, or turn the furnace breakers on and off to reset the electronic ignition circuit.
  • Furnace is producing inadequate heat or airflow. Make sure the air filter is not dirty, and check for closed vents or obstructions in the duct work. Check the thermostat for the proper heat and fan settings, and ensure it has fresh batteries if it requires them.
  • Furnace turns on and off frequently. If you have a mechanical thermostat, make sure the heat anticipator, a small lever located near the main temperature lever, is set to provide a sufficient delay. Adjust it if necessary, noting its previous position if a mistake is made. If you do not have a mechanical thermostat, check for problems such as a clogged air filter or duct obstructions.
  • Furnace is heating, but not moving air. Turn off the furnace breakers and make sure the blower fan belt is intact and tightened properly, adjusting it as required. Be sure all the vents are open and that there are no obvious duct obstructions.
  • Furnace shuts off after several minutes. Check for a dirty flame sensor, and clean it if necessary to ensure it can detect the burner flames, and keep the gas valve open. If the flame sensor is clean, check for a dirty air filter or duct obstructions that could cause the blower motor to overheat.
  • Furnace is making strange noises. If you hear a tapping sound, it could indicate that the blower belt is loose or damaged. Replace the belt or adjust it if necessary. Squealing sounds could indicate a loose belt that requires tightening. Rattling noises may indicate that access covers need to be tightened. Other sounds may signal more serious problems.

If these tips do not solve your furnace problem, you may need to call a professional for a more in-depth diagnosis.

Furnace Repair in McLean & Northern Virginia

When you need help with your furnace in the McLean area, look no further than our team at John Nugent & Sons. Our expert HVAC technicians can diagnose and repair most common furnace problems quickly, and we offer quality repairs for nearly all brands and models. Since 1975, we have been serving homeowners throughout the McLean and Northern Virginia area, providing quality heating, air conditioning, plumbing and electrical services.

Contact John Nugent & Sons today at (703) 291-1926 for quality furnace service and repairs in the McLean area!

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