Your furnace is a key 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 review 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 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 couple of 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 preferred temperature is greater than the room’s current temperature. If you use a programmable thermostat, make sure it has fresh 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 near it. Since this switch looks like a light switch, it’s easy to unintentionally 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 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 varies according to what’s wrong.
2. Furnace Won’t Stay Lit
Your furnace uses a certain sequence when it starts heating your home.
- Your thermostat notices the temperature has fallen and tells your furnace to turn on.
- The draft inducer fan turns on 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 lit.
If something is wrong during the sequence, your furnace will shut down as a preventive measure.
A couple of potential causes for this problem include:
- Dirty or malfunctioning flame sensor. If the sensor doesn’t sense a flame, it will turn off your furnace to keep natural gas from spilling 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 shut off your furnace if it detects backdrafting. Backdrafting is hazardous, because 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 restrict airflow and cause your furnace to shut down to avoid 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 an incorrect thermostat setting or a dusty air filter that’s restricting 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 running for a long time.
If this isn’t what’s happening, ensure 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 sound 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, making your furnace run continuously to make up for the lost air.
Estimated Repair Cost
These costs are estimates, so it’s important 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
Kohles & Bach Heating & Cooling Can Resolve Your Furnace Problems Quickly and Affordably
Furnace issues can be an expensive headache, but not when you call Kohles & Bach Heating & Cooling. We’ve been delivering the quality, affordable furnace repair Des Moines homeowners have trusted since {year}. Call us at 515-207-6569 to receive your free estimate today.