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

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

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

1. Furnace Won’t Turn On

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

  • Is your thermostat set right? Make sure it’s on “heat,” “auto” and that your preferred temperature is higher 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 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 located on or close to it. Because this switch looks like a light switch, it’s easy to accidentally turn it off. If it was off, it may take your furnace a few minutes to start.
  • Is the air filter clean? A dusty air filter can create 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 varies according to what’s wrong.

2. Furnace Won’t Stay Lit

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

  1. Your thermostat notices the temperature has fallen and tells your furnace to turn on.
  2. The draft inducer fan turns on to pull in fresh air for combustion.
  3. The gas valve unlocks for the burners, which are lit electronically.
  4. The flame sensor tells your furnace the burners have been lit.

If something is off during the sequence, your furnace will shut off as a preventive measure.

A couple of possible causes for this issue include:

  • Dirty or malfunctioning flame sensor. If the sensor doesn’t detect a flame, it will shut off your furnace to keep natural gas from spilling 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 turn off your furnace if it detects backdrafting. Backdrafting is dangerous, because carbon monoxide and natural gas can leak into your home. These switches can fail due to age, damage or dust buildup.
  • Old thermostat. If your thermostat isn’t working correctly, your furnace won’t be able to run.
  • Dirty air filter. A dirty air filter can reduce airflow and force your furnace to shut off to avoid overheating. Make sure to change 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 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. Furnace Won’t Blow Hot Air

In many instances, this problem is tied to an incorrect thermostat setting or a dusty air filter that’s limiting airflow. Use the steps above to resolve the issue.

4. Furnace Won’t Turn Off

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

If this isn’t what’s happening, 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 sound like your furnace is running all the time.

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

Estimated Repair Cost

These costs are approximations, so it’s necessary 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

Comfort Zone, LLC Can Solve Your Furnace Problems Quickly and Affordably

Furnace issues can be a costly headache, but not when you work with Comfort Zone, LLC. We’ve been providing the quality, affordable furnace repair Cape Coral homeowners have trusted since {year}. Contact us at 239-214-0411 to request your free estimate today.