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 about what they might cost to fix so you know before you call 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 few 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 resembles a light switch, it’s easy to accidentally turn it off. If it was off, it may take your furnace a few minutes to turn on.
- 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 problem 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 notices the temperature has fallen 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 ignited 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 safety precaution.
A couple of potential 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 eventually need to be taken out and changed.
- Bad limit switch. This safety feature will shut 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 off to prevent overheating. Make sure to change 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 instances, this problem is linked to an incorrect thermostat setting or a dusty air filter that’s limiting 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 toasty, your furnace may be working 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 running 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 losing air, making your furnace run constantly to make up for the lost air.
Estimated Repair Cost
These costs are estimates, 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
Herman Allen Plumbing, Heating & Cooling Can Solve Your Furnace Problems Quickly and Affordably
Furnace issues can be an expensive headache, but not when you call Herman Allen Plumbing, Heating & Cooling. We’ve been providing the quality, affordable furnace repair Greater Richmond homeowners have trusted since 1954. Call us at 804-302-6657 to request your free estimate today.