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 problems that are more typical than others.
Let’s go over these problems and about 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
1. Furnace Won’t Turn On
There are a couple of reasons why your furnace won’t turn on, so make sure to check 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 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 near 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. Get a new one 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 uses a certain sequence when it starts 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 opens for the burners, which are ignited electronically.
- The flame sensor signals to your furnace the burners have been ignited.
If something is off 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 over time. 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 turn off your furnace if it senses backdrafting. Backdrafting is dangerous, because carbon monoxide and natural gas can leak into your home. These switches can malfunction due to age, damage or dust accumulation.
- Old thermostat. If your thermostat isn’t working properly, your furnace won’t be able to run.
- Dirty air filter. A dirty air filter can restrict airflow and force your furnace to shut off 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 cases, this problem is linked to a wrong thermostat setting or a dusty air filter that’s restricting airflow. Follow the steps above to resolve the issue.
4. Furnace Won’t Turn Off
If it’s extremely cold outside or you like your home to be toasty, your furnace may be running for a long time.
If this isn’t the case, make sure your thermostat is set correctly and running 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.
Otherwise, there might be a problem 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 square footage
Fleming Heating & Air Conditioning Inc Can Resolve Your Furnace Problems Quickly and Affordably
Furnace problems can be a costly headache, but not when you work with Fleming Heating & Air Conditioning Inc. We’ve been providing the quality, affordable furnace repair South Beloit and Belvidere homeowners have trusted since 1964. Contact us at 877-389-2465 to request your free estimate today.