Average Repair Costs for Four Typical Furnace Problems

Feb 23, 2024

Author

Jake Nielson

Manager

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 problems that are more common than others.

Let’s review these problems and discuss what they might cost to correct so you know before you contact 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. The Furnace Will Not 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 correctly? Make sure it’s set to “heat,” “auto” and that your desired 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 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. Since this switch looks like a light switch, it’s easy to accidentally 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 create a lot of problems 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 depends on what’s wrong.

2. The Furnace Ignition System Isn’t Working

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

  1. Your thermostat detects the temperature has fallen and tells your furnace to start running.

  2. The draft inducer fan activates to bring in fresh air for combustion.

  3. The gas valve unlocks for the burners, which are lit electronically.

  4. The flame sensor signals to your furnace the burners have been ignited.

If something is off 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 detect 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 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 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 avoid 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 fluctuate 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 Blows Cold Air

In many cases, this problem is linked to a wrong thermostat setting or a dusty air filter that’s limiting airflow. Follow the steps above to fix the problem.

4. The Furnace Isn’t Shutting Off

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

If this isn’t the case, ensure your thermostat is set correctly and working properly. If your fan setting is at “on,” the blower motor will be going 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 losing 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 vary based on your furnace’s brand and model.

  • New blower motor: $250–$800

  • Seal ductwork: varies based on square footage

Schraer Heating & Air Conditioning Can Resolve Your Furnace Problems as Soon as Possible

Furnace problems can be a costly headache, but not when you work with Schraer Heating & Air Conditioning. We’ve been providing the quality, affordable furnace repair Warrenton homeowners have trusted since {year}. Contact us at 636-456-5041 to request your free estimate today.