Your furnace is an integral part of your home. Without one, you wouldn’t be able to keep warm during the winter. Yet furnaces can have some issues that are more common than others.
Let’s review these problems and about 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 check 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 new batteries.
- Is the circuit breaker tripped? Your furnace can’t run 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 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 follows a certain sequence when it begins heating your home.
- Your thermostat notices the temperature has fallen and tells your furnace to start running.
- The draft inducer fan turns on to bring in fresh air for combustion.
- The gas valve opens 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 off as a preventive measure.
A couple of potential causes for this problem 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 as time passes. 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 detects backdrafting. Backdrafting is dangerous, because carbon monoxide and natural gas can seep into your home. These switches can malfunction due to age, damage or dust buildup.
- Old thermostat. If your thermostat isn’t working properly, your furnace won’t be able to run.
- Dirty air filter. A dirty air filter can reduce airflow and force your furnace to shut down 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 an incorrect thermostat setting or a dirty air filter that’s limiting airflow. Follow the steps above to fix the problem.
4. Furnace Won’t Turn Off
If it’s very chilly 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 going even when the furnace isn’t, so it’ll seem like your furnace is running all the time.
Alternatively, 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 estimates, 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
Walter's-Eaton's Electric, Plumbing, Heating & AC Can Resolve Your Furnace Problems Quickly and Affordably
Furnace issues can be a costly headache, but not when you work with Walter's-Eaton's Electric, Plumbing, Heating & AC. We’ve been delivering the quality, affordable furnace repair Ellsworth homeowners have relied on since 1952. Contact us at 715-318-6728 to receive your free estimate today.