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 typical than others.

Let’s go over these problems 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. The Furnace Isn’t Turning On

There are a few 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 set to “heat,” “auto” and that your desired temperature is higher 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 electricity. 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. Since this switch resembles 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 problems for your furnace. Get a new one 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 Ignition System Isn’t Working

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

  1. Your thermostat detects the temperature has dropped and tells your furnace to turn on.
  2. The draft inducer fan turns on to bring 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 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 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 taken out and changed.
  • Bad limit switch. This safety feature will turn off your furnace if it detects backdrafting. Backdrafting is hazardous, because carbon monoxide and natural gas can seep 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 restrict airflow and force your furnace to shut off 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 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 Won’t Blow Hot Air

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

4. My Furnace Isn’t Shutting Off

If it’s very cold 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, 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 running all the time.

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

Estimated Repair Cost

These costs are estimates, so it’s necessary 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

Stieferman Heating Company Inc Can Get to the Bottom of Your Furnace Issues Quickly and Affordably

Furnace issues can be a costly headache, but not when you work with Stieferman Heating Company Inc. We’ve been providing the quality, affordable furnace repair Jefferson City homeowners have relied on since year. Contact us at 573-635-3547 to receive your free estimate today.