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How to Tackle Common Furnace Issues

December 9, 2016

We have all fallen victim to a furnace that hasn’t been run for months, and a furnace’s state can come as a shock when you turn it on when the weather starts to chill. Whether it’s blowing cold air, won’t turn on or the pilot light isn’t on, you may be asking yourself, “how do I fix a furnace?”

Luckily, there are free or low-cost furnace repairs that can be done before calling in an HVAC professional. Continue reading to see how to repair a furnace at home, when it may be time to replace your furnace and when it’s time to call in a professional.

6 Furnace Fixes to Try at Home

Check The Furnace’s Power

Many furnaces have a power switch, either on the unit itself or the wall next to it, that looks just like a light switch. Make sure the switch is turned on, and see if that helps. Also, make sure the unit is properly plugged in.

Change the Furnace Filter

Often, a dirty furnace filter is the culprit in a furnace that isn’t working properly. Filters that are clogged with dust and dirt restrict the amount of airflow that can go through the filter and cause the heat exchanger to overheat and shut off quickly. Plus, the amount of buildup on the filter can cause soot to clog the heat exchanger, reducing the efficiency of the furnace and potentially shortening its life.

Reference the owner’s manual to learn how to remove and replace the furnace filter. There are different types of filters, which include:

  • Disposable fiberglass: These inexpensive flat-panel filters provide the bare minimum needed to protect furnace components from the largest dust particles. However, if you're fighting allergies or have a person suffering from asthma in your home, disposable fiberglass filters aren't your best choice; they don't do much to enhance indoor air quality.
  • Disposable pleated: Pleats add surface area to the filter, helping it remove more particles from your home and boost indoor air quality for a very modest price. They're a better choice for asthma and allergy patients and provide a nice balance between improving air quality and allowing smooth airflow. They do capture a lot of dust and debris so inspect them monthly.
  • High-efficiency pleated: These deeply pleated filters require a special housing to install, but they'll provide you with hospital-grade air purification. Expect to pay a premium for the best air quality available.

Most manufacturers state that pleated filters are good for up to three months, but if you’ve got kids, pets or generate lots of dust, change them more frequently.

How to Fix a Furnace Thermostat

Is your thermostat set to "heat," or is it still set to "cool" from the summer? Check the thermostat batteries. There should be an icon indicating whether the batteries are due for replacement, but switch them out anyway to see if that helps.

Check Your Home’s Circuit Breaker

Is the furnace on? Often, many homeowners think their furnace is broken when in reality, the furnace has been turned off. If you’re unsure where the switch is for the furnace, look for a wall switch on or near the furnace. No matter how old or new a furnace is, there is a switch somewhere.

On the other hand, you find that the system is on and the thermostat has power. Could a circuit have been tripped? Check and see if the furnace's breaker switch is in the "on" or "off" position. If you don't know which is the furnace switch, see if any switches are turned off, and try turning them on again.

How to Fix a Furnace Pilot Light or Ignition

If you have an older furnace, typically 20 or more years old, then the problem may be that the pilot light has gone out. Check it and relight it with a match or lighter. If you don't have an older unit, then it probably doesn't have a continually lit pilot light.

Look at Your Home’s Ductwork

When you turn on the furnace and notice that a few of your home’s rooms are cold, take a look at your home’s ductwork to see if there are gaps between sections or branching points. If you find gaps, seal them with a special metal duct tape. If you use regular duct dupe, it deteriorates quickly and could allow ducts to leak.

When It’s Time to Get a New Furnace

Have you tried some of these furnace fixes and they aren’t working? Some repairs, like replacing parts of the ignition system or the blower motor, make sense as long as you're satisfied with the performance of the furnace. However, if your technician tells you any of the following, it's better to replace:

  • The humidity in your home is rising.
  • It has rust or a cracked heat exchanger.
  • It's more than 20 years old.

Humidity And Your Furnace

Increasing humidity in your home or excessive condensation on your windows can signal serious safety problems with your system. Carbon monoxide is a byproduct of combustion furnaces, and any serious problems associated with the burner or the heat exchanger almost always indicate it's better to replace it. Rising humidity may indicate a leak somewhere in the furnace. When natural gas burns, it creates water vapor, and that vapor contains harmful gasses such as carbon monoxide (CO).

When It’s Time to Call a Lozier Heating and Cooling Professional

If all of your troubleshooting doesn’t seem to be working or if you believe that it’s time to replace your furnace, don’t hesitate to call the HVAC professionals from Lozier Heating and Cooling. If you’ve tried some of these repairs, our experts can help narrow down what your furnace’s issue may be, leading to a quicker diagnosis.

No matter if it’s furnace repairs or furnace replacement, the Lozier Heating and Cooling HVAC technicians can take care of your furnace needs. Contact us at Lozier Heating & Cooling. Our goal is to help educate our customers in the greater Des Moines, Iowa area about energy and home comfort issues (specific to HVAC systems).