Your furnace is an integral part of your home. Without one, you wouldn’t be able to stay warm during the winter. Yet furnaces can have some problems that are more common than others.

Let’s review these problems and discuss what they might cost to fix so you know before you call an HVAC technician. Some of the most common furnace repair issues involve:

  • Furnace won’t turn on
  • Furnace doesn’t stay lit
  • Furnace won’t blow hot air
  • Furnace won’t turn off

1. My Furnace Won’t Turn On

There are a couple of reasons why your furnace won’t turn on, so make sure to go through all of them.

  • Is your thermostat set right? Make sure it’s on “heat,” “auto” and that your preferred temperature is greater than the room’s current temperature. If you have a programmable thermostat, make sure it has fresh batteries.
  • Is the circuit breaker tripped? Your furnace can’t operate if it doesn’t have power. Reset the switch if it’s facing the outside of the electrical panel.
  • Is the furnace switch off? Your furnace has a power switch found on or near it. Because this switch looks like a light switch, it’s easy to unintentionally turn it off. If it was off, it might take your furnace a few minutes to turn on.
  • Is the air filter clean? A dirty air filter can cause a lot of issues for your furnace. Get a new one if you can’t see light through it.

Estimated Repair Cost

This issue can be complex, so the estimated cost to repair it depends on what’s wrong.

2. My Furnace Isn’t Staying Lit

Your furnace uses a specific sequence when it begins heating your home.

  1. Your thermostat detects the temperature has dropped and tells your furnace to start running.
  2. The draft inducer fan activates to pull in fresh air for combustion.
  3. The gas valve opens for the burners, which are lit electronically.
  4. The flame sensor signals to your furnace the burners have been lit.

If something is wrong during the sequence, your furnace will shut down as a safety precaution.

A couple of potential causes for this issue include:

  • Dirty or malfunctioning flame sensor. If the sensor doesn’t sense a flame, it will shut off your furnace to prevent natural gas from getting into your home. The ignition process corrodes flame sensors as time passes. While cleaning during annual furnace maintenance can help, yours may ultimately need to be replaced.
  • Bad limit switch. This safety feature will shut off your furnace if it senses backdrafting. Backdrafting is dangerous, since carbon monoxide and natural gas can leak into your home. These switches can malfunction due to age, damage or dust buildup.
  • Old thermostat. If your thermostat isn’t working properly, your furnace won’t be able to operate.
  • Dirty air filter. A dirty air filter can limit airflow and force your furnace to shut down to prevent overheating. Make sure to replace yours every 30 to 90 days, or anytime you can’t see light through it.

Estimated Repair Cost

These costs are estimates, so it’s important to note yours may vary based on your furnace’s brand and model.

  • Flame sensor: $350–$500
  • Limit switch: $150–$300
  • Thermostat: $150–$350
  • Furnace filter: $10-$30

3. The Furnace Blows Cold Air

In many cases, this problem is linked to a wrong thermostat setting or a dirty air filter that’s restricting airflow. Use the steps above to resolve the problem.

4. My Furnace Isn’t Shutting Off

If it’s very chilly outside or you like your home to be warm, your furnace may be working for a long time.

If this isn’t the case, make sure your thermostat is set correctly and running properly. If your fan setting is at “on,” the blower motor will be running even when the furnace isn’t, so it’ll seem like your furnace is on all the time.

Otherwise, there might be a problem with the blower motor or your ductwork may be leaking air, forcing your furnace to run constantly to make up for the air loss.

Estimated Repair Cost

These costs are approximations, so it’s important to note yours may vary based on your furnace’s brand and model.

  • New blower motor: $250–$800
  • Seal ductwork: varies based on square footage

Air-Right Energy Design Will Work Hard to Get to the Bottom of Your Furnace Problems Quickly and Affordably

Furnace issues can be an expensive headache, but not when you work with Air-Right Energy Design. We’ve been providing the quality, affordable furnace repair Manassas homeowners have relied on since {year}. Contact us at 703-260-1148 to request your free estimate today.