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 issues that are more common than others.
Let’s review these issues and discuss what they might cost to correct 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 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 higher than the room’s current temperature. If you have a programmable thermostat, make sure it has fresh 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 found 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 turn on.
- 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 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 uses a certain sequence when it starts heating your home.
- Your thermostat detects the temperature has fallen and tells your furnace to start running.
- 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 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 issue 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 replaced.
- Bad limit switch. This safety feature will turn off your furnace if it detects 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 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 tied to a wrong thermostat setting or a dirty air filter that’s limiting 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 warm, 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 on all the time.
Otherwise, there might be a problem with the blower motor or your ductwork may be leaking air, making your furnace 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 house size
Precision Mechanical Can Solve Your Furnace Issues Quickly and Affordably
Furnace problems can be an expensive headache, but not when you call Precision Mechanical. We’ve been providing the quality, affordable furnace repair Rapid City homeowners have relied on since {year}. Contact us at 605-206-3766 to request your free estimate today.
