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 go over these issues 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 include:
- 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 correctly? 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 found on or close to it. Since this switch resembles 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 create a lot of problems for your furnace. Get a new one if you can’t see light through it.
Estimated Repair Cost
This issue can be complex, so the estimated cost to repair it varies according to what’s wrong.
2. Furnace Won’t Stay Lit
Your furnace follows a specific sequence when it starts heating your home.
- Your thermostat detects the temperature has dropped and tells your furnace to turn on.
- The draft inducer fan turns on to pull in fresh air for combustion.
- The gas valve opens for the burners, which are ignited 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 safety precaution.
A couple of possible 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 getting into your home. The ignition process corrodes flame sensors as time passes. 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 seep into your home. These switches can malfunction due to age, damage or dust accumulation.
- 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 restrict airflow and cause 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 instances, this problem is tied to a wrong thermostat setting or a dirty air filter that’s restricting airflow. Use the steps above to resolve the problem.
4. Furnace Won’t Turn Off
If it’s extremely chilly outside or you like your home to be toasty, your furnace may be working 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 constantly to make up for the lost air.
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
GV Heating & Air Can Solve Your Furnace Problems Quickly and Affordably
Furnace problems can be an expensive headache, but not when you call GV Heating & Air. We’ve been providing the quality, affordable furnace repair Crystal and Twin Cities homeowners have trusted since . Call us at 763-535-2000 to request your free estimate today.