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

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

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

1. The Furnace Can’t Start

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

  • Is your thermostat set correctly? Make sure it’s set to “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 new batteries.
  • Is the circuit breaker tripped? Your furnace can’t run 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 close to it. Because this switch resembles a light switch, it’s easy to unintentionally turn it off. If it was off, it may take your furnace a few minutes to turn on.
  • Is the air filter clean? A dirty air filter can create a lot of issues for your furnace. Replace yours if you can’t see light through it.

Estimated Repair Cost

This issue can be complicated, so the estimated cost to repair it varies according to what’s wrong.

2. The Furnace Isn’t Staying Lit

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

  1. Your thermostat detects the temperature has fallen and tells your furnace to start running.
  2. The draft inducer fan turns on to pull in fresh air for combustion.
  3. The gas valve opens for the burners, which are ignited electronically.
  4. The flame sensor tells 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 problem include:

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

Estimated Repair Cost

These costs are estimates, so it’s necessary 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. My Furnace Is Blowing Cold Air

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

4. My Furnace Won’t Turn Off

If it’s extremely cold outside or you like your home to be toasty, your furnace may be running for a long time.

If this isn’t what’s happening, ensure your thermostat is set correctly and working 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.

Alternatively, there might be an issue with the blower motor or your ductwork may be leaking air, forcing your furnace to run continuously to make up for the lost air.

Estimated Repair Cost

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

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

Controlled Comfort HVAC Can Solve Your Furnace Problems as Soon as Possible

Furnace issues can be an expensive headache, but not when you call Controlled Comfort HVAC. We’ve been delivering the quality, affordable furnace repair Carpentersville homeowners have relied on since {year}. Call us at 224-412-8308 to request your free estimate today.