Your furnace is an integral part of your home. Without one, you wouldn’t be able to keep warm during the winter. Yet furnaces can have some problems that are more typical than others.

Let’s go over these problems and discuss what they might cost to correct 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. Furnace Won’t Turn On

There are a few 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 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 found on or close to 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 start.
  • Is the air filter clean? A dusty 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 fallen and tells your furnace to start running.
  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 off 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 shut off your furnace to keep 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 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 hazardous, 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 reduce airflow and cause your furnace to shut down to avoid overheating. Make sure to change 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 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. Furnace Won’t Blow Hot Air

In many cases, this problem is tied to a wrong thermostat setting or a dirty air filter that’s limiting 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, 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 seem like your furnace is on all the time.

Otherwise, there might be a problem with the blower motor or your ductwork may be losing air, forcing your furnace to run continuously to make up for the lost air.

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

Fairfield Heating & Cooling Can Resolve Your Furnace Problems Quickly and Affordably

Furnace issues can be an expensive headache, but not when you call Fairfield Heating & Cooling. We’ve been delivering the quality, affordable furnace repair Lancaster homeowners have relied on since {year}. Contact us at 740-331-4331 to request your free estimate today.