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

  • 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 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 use a programmable thermostat, make sure it has new batteries.
  • Is the circuit breaker tripped? Your furnace can’t operate 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 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 start.
  • Is the air filter clean? A dusty 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 problem 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 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 activates 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 ignited.

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

A couple of possible causes for this problem 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 spilling 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 hazardous, 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 run.
  • Dirty air filter. A dirty air filter can reduce airflow and cause your furnace to shut off to prevent overheating. Make sure to change 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 necessary 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. Furnace Won’t Blow Hot Air

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

4. Furnace Won’t Turn Off

If it’s very 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, make sure 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 running all the time.

Alternatively, 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 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 house size

Evenaire Heating & Air Conditioning Can Solve Your Furnace Issues Quickly and Affordably

Furnace issues can be a costly headache, but not when you call Evenaire Heating & Air Conditioning. We’ve been providing the quality, affordable furnace repair Pflugerville homeowners have relied on since {year}. Contact us at 512-355-1482 to receive your free estimate today.