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 common 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 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 couple of 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 set to “heat,” “auto” and that your preferred 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 operate 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 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 start.
- 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 issue 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 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 activates to pull in fresh air for combustion.
- The gas valve unlocks for the burners, which are lit electronically.
- The flame sensor signals to your furnace the burners have been lit.
If something is off during the sequence, your furnace will shut off as a preventive measure.
A couple of possible causes for this issue include:
- Dirty or malfunctioning flame sensor. If the sensor doesn’t detect a flame, it will turn off your furnace to prevent 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 eventually need to be replaced.
- Bad limit switch. This safety feature will turn off your furnace if it detects backdrafting. Backdrafting is dangerous, because carbon monoxide and natural gas can leak into your home. These switches can fail 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 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 necessary to note yours may fluctuate 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 restricting airflow. Use the steps above to fix the issue.
4. Furnace Won’t Turn Off
If it’s extremely cold outside or you like your home to be warm, 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 running all the time.
Otherwise, there might be an issue with the blower motor or your ductwork may be leaking air, forcing your furnace to run constantly to make up for the air loss.
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
Lakeside Heating & Air Can Solve Your Furnace Problems Quickly and Affordably
Furnace problems can be an expensive headache, but not when you work with Lakeside Heating & Air. We’ve been providing the quality, affordable furnace repair Chelan and Wenatchee homeowners have relied on since 2001. Call us at 509-284-4265 to receive your free estimate today.