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 problems that are more typical 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 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 desired 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 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 may take your furnace a few minutes to start.
- 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 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 bring 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 down 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 getting 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 shut 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 properly, your furnace won’t be able to operate.
- Dirty air filter. A dirty air filter can limit airflow and force your furnace to shut down to avoid overheating. Make sure to replace 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 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 instances, this problem is linked to a wrong thermostat setting or a dirty air filter that’s restricting airflow. Use the steps above to resolve the issue.
4. Furnace Won’t Turn Off
If it’s extremely chilly outside or you like your home to be warm, your furnace may be running 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.
Otherwise, there might be an issue with the blower motor or your ductwork may be leaking air, making your furnace run continuously 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 house size
H&C Heating and Cooling Can Resolve Your Furnace Problems Quickly and Affordably
Furnace problems can be a costly headache, but not when you work with H&C Heating and Cooling. We’ve been providing the quality, affordable furnace repair Laurel homeowners have relied on since 1969. Contact us at 301-960-3247 to receive your free estimate today.