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 common than others.
Let’s review these problems 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 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 use a programmable thermostat, make sure it has new batteries.
- Is the circuit breaker tripped? Your furnace can’t operate 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 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 turn on.
- Is the air filter clean? A dusty air filter can cause 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 follows a specific sequence when it starts heating your home.
- Your thermostat notices the temperature has dropped and tells your furnace to turn on.
- The draft inducer fan activates to bring in fresh air for combustion.
- The gas valve unlocks for the burners, which are lit electronically.
- The flame sensor tells your furnace the burners have been ignited.
If something is off during the sequence, your furnace will shut off 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 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 turn off your furnace if it detects backdrafting. Backdrafting is hazardous, since 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 correctly, your furnace won’t be able to run.
- Dirty air filter. A dirty air filter can reduce airflow and force 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 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 tied to a wrong thermostat setting or a dirty air filter that’s limiting airflow. Use the steps above to fix the issue.
4. Furnace Won’t Turn Off
If it’s very 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 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.
Alternatively, there might be a problem with the blower motor or your ductwork may be losing air, making your furnace 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 square footage
Controlled Comfort HVAC Inc Can Resolve Your Furnace Issues Quickly and Affordably
Furnace issues can be a costly headache, but not when you call Controlled Comfort HVAC Inc. We’ve been delivering the quality, affordable furnace repair Carpentersville homeowners have trusted since 2007. Call us at 224-412-8308 to request your free estimate today.