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 issues that are more typical than others.

Let’s review these problems and discuss what they might cost to fix so you know before you contact an HVAC technician. Some of the most common furnace repair issues 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 check all of them.

  • Is your thermostat set correctly? Make sure it’s set to “heat,” “auto” and that your preferred temperature is greater 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 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 located 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 dusty air filter can cause 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. Furnace Won’t Stay Lit

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

  1. Your thermostat notices the temperature has dropped and tells your furnace to start running.
  2. The draft inducer fan turns on to bring in fresh air for combustion.
  3. The gas valve opens 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 preventive measure.

A couple of potential causes for this problem include:

  • Dirty or malfunctioning flame sensor. If the sensor doesn’t sense a flame, it will turn 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 replaced.
  • Bad limit switch. This safety feature will turn off your furnace if it detects backdrafting. Backdrafting is dangerous, 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 properly, 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 anytime you can’t see light through it.

Estimated Repair Cost

These costs are estimates, so it’s necessary 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. Furnace Won’t Blow Hot Air

In many instances, 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. Furnace Won’t Turn Off

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

If this isn’t the case, ensure your thermostat is set correctly and running properly. If your fan setting is at “on,” the blower motor will be running even when the furnace isn’t, so it’ll sound like your furnace is running all the time.

Alternatively, there might be an issue with the blower motor or your ductwork may be leaking air, forcing your furnace to run continuously to make up for the lost air.

Estimated Repair Cost

These costs are approximations, 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

Ilten's Can Resolve Your Furnace Issues Quickly and Affordably

Furnace issues can be a costly headache, but not when you work with Ilten's. We’ve been delivering the quality, affordable furnace repair Cedar Rapids homeowners have trusted since {year}. Call us at 319-208-2351 to receive your free estimate today.