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 issues that are more common than others.

Let’s go over these problems and discuss what they might cost to fix 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. My Furnace Will Not 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 correctly? Make sure it’s on “heat,” “auto” and that your desired 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. Because this switch looks like 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 dusty 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 problem can be complex, so the estimated cost to repair it varies according to what’s wrong.

2. My Furnace Ignition System Isn’t Working

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

  1. Your thermostat notices the temperature has dropped and tells your furnace to turn on.
  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 possible causes for this problem include:

  • Dirty or malfunctioning flame sensor. If the sensor doesn’t detect a flame, it will turn 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 eventually need to be replaced.
  • Bad limit switch. This safety feature will shut off your furnace if it detects backdrafting. Backdrafting is dangerous, 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 operate.
  • Dirty air filter. A dirty air filter can limit airflow and cause your furnace to shut down 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. The 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 restricting airflow. Follow the steps above to resolve the problem.

4. The Furnace Won’t Turn Off

If it’s extremely cold outside or you like your home to be warm, your furnace may be working 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 going 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 leaking air, forcing your furnace to run continuously to make up for the air loss.

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

Bell Mechanical Services Will Work Hard to Resolve Your Furnace Problems as Soon as Possible

Furnace problems can be an expensive headache, but not when you call Bell Mechanical Services. We’ve been providing the quality, affordable furnace repair McKinney and Frisco homeowners have trusted since year. Contact us at 888-863-0560 to receive your free estimate today.