Your furnace is a key part of your home. Without one, you wouldn’t be able to stay warm during the winter. Yet furnaces can have some issues that are more typical than others.
Let’s review these issues and about 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. 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 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 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 close to it. Since 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 dirty 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 issue can be complicated, so the estimated cost to repair it depends on what’s wrong.
2. Furnace Won’t Stay Lit
Your furnace uses a certain sequence when it begins heating your home.
- Your thermostat detects the temperature has fallen and tells your furnace to turn on.
- The draft inducer fan activates to pull 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 wrong during the sequence, your furnace will shut off as a preventive measure.
A couple of potential causes for this issue include:
- Dirty or malfunctioning flame sensor. If the sensor doesn’t detect 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 replaced.
- Bad limit switch. This safety feature will shut off your furnace if it detects 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 operate.
- Dirty air filter. A dirty air filter can reduce airflow and force your furnace to shut off to avoid overheating. Make sure to replace 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
3. 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 limiting airflow. Follow the steps above to resolve the problem.
4. Furnace Won’t Turn Off
If it’s very chilly outside or you like your home to be toasty, 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 going even when the furnace isn’t, so it’ll seem like your furnace is running all the time.
Alternatively, there might be an issue with the blower motor or your ductwork may be losing air, making your furnace run continuously 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 square footage
Siloam Springs Heating & AC Can Resolve Your Furnace Problems Quickly and Affordably
Furnace issues can be an expensive headache, but not when you work with Siloam Springs Heating & AC. We’ve been providing the quality, affordable furnace repair Siloam Springs homeowners have relied on since 1992. Call us at 479-308-8176 to request your free estimate today.