Estimated Repair Costs for 4 Common Furnace Problems

November 30, 2021

Your furnace is a key part of your home. Without one, you wouldn’t be able to keep warm during cold weather. Yet furnaces can have some issues that are more common than others.

Let’s go over these issues and about what they might cost to correct so you know before you call an HVAC technician. Some of the most common furnace repair issues involve:

  • 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 few 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 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 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 found on or near 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 dirty air filter can create a lot of issues for your furnace. Replace yours if you can’t see light through it.

Estimated Repair Cost

This problem can be complex, so the estimated cost to repair it depends on what’s wrong.

2. Furnace Won’t Stay Lit

Your furnace uses a specific sequence when it begins 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 ignited 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 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 spilling 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 senses 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 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 prevent 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 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 instances, this problem is linked to an incorrect thermostat setting or a dusty air filter that’s restricting airflow. Use the steps above to resolve the problem.

4. Furnace Won’t Turn Off

If it’s extremely 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 running even when the furnace isn’t, so it’ll seem like your furnace is on all the time.

Otherwise, there might be an issue 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 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

Colvin's Heating and Cooling Can Solve Your Furnace Issues Quickly and Affordably

Furnace problems can be an expensive headache, but not when you work with Colvin's Heating and Cooling. We’ve been providing the quality, affordable furnace repair Excelsior Springs homeowners have relied on since 1988. Contact us at 816-379-3918 to request your free estimate today.