Your furnace is a key part of your home. Without one, you wouldn’t be able to stay warm during cold weather. Yet furnaces can have some problems that are more typical 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 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 correctly? 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 fresh 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 start.
  • 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 complex, so the estimated cost to repair it depends on what’s wrong.

2. The Furnace Won’t Stay Lit

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

  1. Your thermostat detects the temperature has fallen and tells your furnace to start running.
  2. The draft inducer fan turns on to pull in fresh air for combustion.
  3. The gas valve opens 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 off as a safety precaution.

A couple of possible causes for this problem include:

  • Dirty or malfunctioning flame sensor. If the sensor doesn’t sense 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, since carbon monoxide and natural gas can leak into your home. These switches can fail due to age, damage or dust accumulation.
  • 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 replace 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 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. The Furnace Blows Cold Air

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

4. The Furnace Isn’t Shutting 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, ensure your thermostat is set correctly and running 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 an issue with the blower motor or your ductwork may be losing air, forcing your furnace to run continuously to make up for the air loss.

Estimated Repair Cost

These costs are approximations, 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 house size

Temperature Doctors Heating & Cooling Will Work Hard to Solve Your Furnace Issues as Soon as Possible

Furnace problems can be a costly headache, but not when you work with Temperature Doctors Heating & Cooling. We’ve been providing the quality, affordable furnace repair Rockford homeowners have relied on since year. Contact us at (815) 914-6197 to request your free estimate today.