Your furnace is an integral 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 review these issues and discuss 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. The Furnace Can’t Start

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 correctly? Make sure it’s on “heat,” “auto” and that your desired 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 run 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 close to it. Since this switch resembles 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 create a lot of issues 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. The Furnace Isn’t Staying Lit

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

  1. Your thermostat detects the temperature has fallen and tells your furnace to turn on.
  2. The draft inducer fan activates to pull in fresh air for combustion.
  3. The gas valve opens for the burners, which are ignited electronically.
  4. The flame sensor tells your furnace the burners have been lit.

If something is wrong 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 sense a flame, it will turn off your furnace to prevent natural gas from getting 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 replaced.
  • Bad limit switch. This safety feature will shut off your furnace if it detects backdrafting. Backdrafting is hazardous, because carbon monoxide and natural gas can leak into your home. These switches can malfunction due to age, damage or dust buildup.
  • 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 force your furnace to shut down 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. My 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. Use the steps above to resolve the problem.

4. My Furnace Isn’t Shutting Off

If it’s extremely chilly outside or you like your home to be warm, 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 running 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 constantly to make up for the air loss.

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

Better Air Will Work Hard to Solve Your Furnace Issues Quickly and Affordably

Furnace problems can be an expensive headache, but not when you work with Better Air. We’ve been delivering the quality, affordable furnace repair Dundas and Northfield homeowners have relied on since year. Call us at 507-663-1208 to receive your free estimate today.