Average Repair Costs for 4 Typical Furnace Issues

November 30, 2021

Your furnace is an integral 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 go over these issues and about what they might cost to fix so you know before you contact 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 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 on “heat,” “auto” and that your preferred temperature is higher than the room’s current temperature. If you have a programmable thermostat, make sure it has new 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 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 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. 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 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 ignited electronically.
  4. The flame sensor signals to your furnace the burners have been lit.

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

A couple of possible causes for this issue include:

  • Dirty or malfunctioning flame sensor. If the sensor doesn’t sense a flame, it will turn 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 eventually need to be taken out and changed.
  • Bad limit switch. This safety feature will shut off your furnace if it detects backdrafting. Backdrafting is dangerous, since carbon monoxide and natural gas can seep 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 operate.
  • Dirty air filter. A dirty air filter can restrict airflow and cause your furnace to shut down to prevent 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 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 cases, this problem is linked to an incorrect thermostat setting or a dusty air filter that’s restricting airflow. Follow the steps above to fix the issue.

4. Furnace Won’t Turn Off

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

If this isn’t the case, 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 sound like your furnace is on 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 necessary 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

Tri City Fuel & Heating Co., Inc. Can Resolve Your Furnace Problems Quickly and Affordably

Furnace problems can be an expensive headache, but not when you call Tri City Fuel & Heating Co., Inc.. We’ve been delivering the quality, affordable furnace repair West Columbia homeowners have relied on since 1964. Contact us at 803-265-4208 to request your free estimate today.