Estimated Repair Costs for Four Common Furnace Issues

Estimated Repair Costs For Four Common Furnace Issues

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 discuss what they might cost to fix 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

The 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 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 found on or near it. Because this switch looks like a light switch, it’s easy to accidentally 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 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 complex, so the estimated cost to repair it depends on what’s wrong.

The Furnace Ignition System Isn’t Working

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

Your thermostat notices the temperature has fallen and tells your furnace to start running.
The draft inducer fan activates to pull in fresh air for combustion.
The gas valve opens for the burners, which are lit electronically.
The flame sensor tells your furnace the burners have been ignited.

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

A couple of possible causes for this problem include:

Dirty or malfunctioning flame sensor. If the sensor doesn’t sense a flame, it will shut 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 taken out and changed.
Bad limit switch. This safety feature will turn off your furnace if it detects backdrafting. Backdrafting is hazardous, because 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 limit airflow and force your furnace to shut down to prevent 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 vary based on your furnace’s brand and model.

Flame sensor: $350–$500
Limit switch: $150–$300
Thermostat: $150–$350
Furnace filter: $10-$30

My Furnace Blows Cold 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 problem.

My Furnace Can’t Shut Down

If it’s extremely cold 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 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 continuously to make up for the lost air.