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 typical than others.

Let’s review these issues and discuss what they might cost to correct 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 few reasons why your furnace won’t turn on, so make sure to check all of them.

  • Is your thermostat set right? 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 new 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 close to it. Since this switch resembles a light switch, it’s easy to unintentionally turn it off. If it was off, it might take your furnace a few minutes to start.
  • Is the air filter clean? A dirty air filter can cause a lot of issues for your furnace. Get a new one if you can’t see light through it.

Estimated Repair Cost

This issue can be complex, so the estimated cost to repair it varies according to what’s wrong.

2. Furnace Won’t Stay Lit

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

  1. Your thermostat notices the temperature has fallen and tells your furnace to start running.
  2. The draft inducer fan activates to pull in fresh air for combustion.
  3. The gas valve unlocks 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 off as a safety precaution.

A couple of potential 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 ultimately need to be taken out and changed.
  • Bad limit switch. This safety feature will shut off your furnace if it senses backdrafting. Backdrafting is dangerous, since carbon monoxide and natural gas can seep into your home. These switches can malfunction due to age, damage or dust buildup.
  • 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 limit 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 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 tied to an incorrect thermostat setting or a dusty air filter that’s limiting airflow. Use 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 working for a long time.

If this isn’t what’s happening, ensure 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.

Alternatively, 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 lost air.

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

North Mechanical Heating and Cooling Can Solve Your Furnace Problems Quickly and Affordably

Furnace problems can be an expensive headache, but not when you call North Mechanical Heating and Cooling. We’ve been delivering the quality, affordable furnace repair Payson homeowners have relied on since {year}. Contact us at 928-263-8570 to receive your free estimate today.