When your furnace runs but fails to blow air, several issues could be at play: Blower Motor Problems: If the motor is malfunctioning or not receiving power, it can't push air through your ducts. This could be due to electrical issues, a faulty motor, or problems with the motor's capacitor.
Every modern furnace is equipped with a safety shutoff that will be tripped if your furnace gets too hot, and a clogged air filter can cause your furnace to overheat, shut itself off and give you the illusion of a furnace not blowing air.
If the filter is clogged, replace or clean it immediately, then rerun the furnace. If this does not correct the airflow issue, make the call for help, as it's likely an issue with an internal component, such as the blower or control board, that will require an experienced technician to diagnose and repair.
Ensure your thermostat has not been set to a lower setting by someone else. Check your thermostat's batteries and replace any that are exhausted or defective. Clean all of the parts of your furnace, especially the ones that are susceptible to dust and dirt.
Airflow Problems
When you turn the furnace on but no heat comes out, there may be an obstruction. Dirty air filters restrict airflow, which can make it feel like not much heated air is coming out of your vents. Check the furnace filter and replace it if its surface is covered with contaminants.
This could be due to electrical issues, a faulty motor, or problems with the motor's capacitor. Clogged Air Filters: Dirty or clogged air filters restrict airflow, preventing your furnace from circulating air effectively. Thermostat Issues: Sometimes, the problem lies not with the furnace but the thermostat.
The implications of inadequate air are significant. The incomplete combustion process will generate carbon monoxide (the poisonous gas). Further, the lack of dilution air is likely to result in backdraft.
Furnace is not producing heat.
Possible causes include a broken thermostat; the thermostat being set too low; an out pilot light; a blown fuse or circuit breaker; a closed gas valve; or electronic ignition problems.
Possible reasons include thermostat issues (incorrect settings or dead batteries), power problems (tripped circuit breaker or blown fuse), and furnace malfunctions (dirty air filter, faulty ignition system, or tripped safety switches). Checking these areas can help identify the issue.
You also want to check the vents for any obstructions that could be blocking the airflow. If you notice any, clear the obstructions and you will hopefully have fixed your issue. If you are still experiencing lack of air coming from your vents, your thermostat is the next likely culprit.
Check Furnace Thermostat Settings
Incorrect thermostat settings can be the cause behind no heat coming out of the vents, even with the furnace blower turned on. Check the thermostat to ensure the setting is in HEAT instead of COOL. It is a common mistake that happens. The fan runs continuously when it is switched on.
The most common problems that cause a lack of airflow include frozen coils, broken fan and restricted airflow due to dirty air filters or vent obstruction. However, there are many other issues that can lead to minimal airflow, so it may be necessary to ask the professionals.
Most likely, your furnace is making a clicking noise and not providing heat because your furnace's spark igniter is trying to ignite your pilot light or burners but is failing to do so. In other words, there's an ignition system malfunction that needs to be fixed. Otherwise, your furnace won't start.
While furnaces can stop operating for complicated reasons, home owners should check a few usual suspects first behind a lack of hot blowing air: Electrical problems causing a loss of power. Blocked air vents and ducts restricting airflow. Improperly configured thermostat settings.
Troubleshooting your furnace blower when it's not working can be a step-by-step process: Check for Electrical Issues: Inspect the furnace circuit for blown fuses and reset circuit breakers if necessary. Inspect the Air Filter: Examine the air filter for debris and dust buildup and replace it if dirty.
Replacing a furnace blower motor costs $560, on average. Depending on the size and type of motor, most people pay $300 to $900. The average blower motor replacement cost is $560, but the final price depends on labor fees, as well as the cost of the parts.
The cause of your furnace not blowing hot air could be the thermostat configuration, a dirty air filter, the high limit switch, a clogged condensate line, insufficient fuel, leaky ducts, ignition problems, a blocked burner, flame sensor issues, gas valve malfunctions, a cracked heat exchanger, or a clogged coil.
Checking your thermostat is the best place to start. Make sure it's set to “heat” and that you've set the temperature higher than the current room temperature. If that doesn't resolve the problem, try switching your fan to “on” to force the furnace to start working.
It's most likely an incorrect thermostat setting if you find your furnace blowing warm air, not hot. The fan is set to “on” instead of “auto.” Furnaces only pump hot air until the thermostat setting is reached, so if your fan is always on, it will blow both hot air when the furnace is heating and cold when it's not.
Four common reasons there isn't enough hot air blowing out of your vents are: A Vent is Blocked. The Air Filter is Clogged. Leaky Ductwork.
First, turn off the power supply to the furnace by turning off the breaker in the circuit box. Locate the reset button on the furnace and press it to reset the furnace. It is usually located inside the blower compartment on the side of the blower motor. Be cautious, as the housing may be hot.
If your boiler or furnace is in an enclosed space and relies on indoor air for combustion, you run the risk of incomplete combustion, which produces toxic byproducts like carbon monoxide.