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 discuss what they might cost to fix so you know before you contact 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 set to “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 run 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 close to it. Since this switch resembles a light switch, it’s easy to unintentionally turn it off. If it was off, it may take your furnace a few minutes to start.
- Is the air filter clean? A dirty air filter can create a lot of issues for your furnace. Replace yours if you can’t see light through it.
Estimated Repair Cost
This problem can be complicated, so the estimated cost to repair it varies according to 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 start running.
- 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 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 shut 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 taken out and changed.
- Bad limit switch. This safety feature will turn off your furnace if it senses backdrafting. Backdrafting is dangerous, since 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 prevent 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 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, make sure 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 sound like your furnace is on all the time.
Otherwise, there might be an issue with the blower motor or your ductwork may be losing air, forcing your furnace to run continuously to make up for the air loss.
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
Air Alliance Team Can Solve Your Furnace Problems Quickly and Affordably
Furnace problems can be a costly headache, but not when you call Air Alliance Team. We’ve been delivering the quality, affordable furnace repair Ballwin and St. Charles homeowners have trusted since {year}. Contact us at 636-206-4250 to request your free estimate today.