If your air handler is running but not blowing air, there are two likely scenarios: either a broken AC blower belt or an issue with the motor itself. If the air handler is humming or buzzing but not making the mechanical sounds of a motor running, you're most likely talking about an issue with the motor itself.
Most vents have a switch or toggle to open and close the vents – you want to make sure that none of your vents have been inadvertently closed. 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.
Obstructed Vent
Furniture, bedding, and the vent damper could all be possible obstacles to the vent. If you find any closed or blocked vents, you can clear away the obstruction and feel for airflow, but if your vents are open and still not blowing enough air, there could be an issue with the fan's motor.
It could be several things: IF it was working, then stopped, it could be the starter capacitor on the blower. If some vents are blowing good, but others are not, it could need balancing. It could be a clogged filter.
If your AC unit and furnace fan is running but you still have no airflow your most likely have a frozen evaporator coil. Caused by either an airflow issue like plugged air filter or plugged evaporator coil. Or your AC unit could have a refrigerant leak and be low on charge.
If your air handler is running but not blowing air, there are two likely scenarios: either a broken AC blower belt or an issue with the motor itself. If the air handler is humming or buzzing but not making the mechanical sounds of a motor running, you're most likely talking about an issue with the motor itself.
A bad thermostat can be detected when your AC or furnace is not turning on, your HVAC systems are not turning off, the thermostat not responding, your HVAC system is short-cycling, the room temperature not matching the temperature displayed on the thermostat, and the programmed setting resetting themselves.
If you can hear your AC running, but the fan isn't kicking on you will want to try lowering the temperature on your thermostat a few degrees. If your fan is still suspiciously quiet, this can be an indication of an issues with the AC blower. The AC blower pushes the cold air out to the ductwork and through your house.
If your ceiling fan isn't blowing air, one potential reason is electrical issues. This can be caused by a variety of factors including a blown fuse, loose wiring, a problem with the dual or single capacitors, or a defective motor.
If your inside unit is running but the outside AC unit fan isn't running, there could be a few potential causes. To diagnose the problem, first, check the circuit breaker, then inspect the condensing unit for any visible damage, and then check if the fan's airflow is blocked.
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.
Check the air filter and replace the filter if it's dirty. Look for dirt clogging the condenser fins on the outside unit and clean the fins if necessary. Check for a clogged condensate drain line and clear the clog if condensate water isn't draining from the unit.
You can generally identify a blocked air duct by a distinct drop in heating and cooling efficiency, increased energy costs, and occasionally a musty, dusty smell throughout the home. The blockage usually comes over time, by a buildup of dust and debris that just accumulates until it begins choking the system.
This could be a voltage issue or simply a faulty thermostat to blame. Duct Blockage. If some registers are blowing and others are not, you may have a blockage issue in the ductwork. If there is no collapse, then a thorough duct cleaning may fix your airflow problems.
There are a number of reasons why your air conditioner might be running but not cooling. It could be an issue with the thermostat, the compressor, or the evaporator coils. Or, it could simply be clogged with dust and debris, which is preventing it from working properly.
In AC systems, the air conditioner reset button is on the outside unit's lower edge, typically close to the ground. Some models have the reset button located behind the service panel, which may require tools to remove. Reset buttons are usually red or yellow with a clear “reset” label.
In short, common issues that can cause an air conditioning unit fan to stop spinning are electrical issues, problems with the capacitor, contactor issues, a burnt out air conditioner motor, a broken fan belt, or clogged air filter.
You go to turn on your air conditioner but nothing happens. Why? Usually, it means that your system is not receiving power or that your thermostat is not set correctly. Make sure that your thermostat is set to “cool.” You may also need to adjust the temperature that it's set to.
The most common reasons for a radiator fan not working can be a blown-out fuse, a bad relay, or a broken wire. The faulty coolant temp sensor might also be a reason behind it. Whatever the case, a dysfunctional radiator fan can be fatal.
Power down your AC: Turn off your AC unit and unplug it from the power source. This will ensure that you stay safe while working on the unit. Locate the reset button: Most air conditioning units have a reset button located near the outside unit. It is usually a small button located inside a small hole.
The short answer: Definitely not. (Unless you have manually engaged your outside fan to run constantly, but it shouldn't be running for hours on it's own.) If your HVAC is functioning correctly, it should keep your house cool by cycling on for 15-20 minutes at a time—with distinct pauses in between each cycle.
Short cycling indicates a problem within a heater that is cutting off its heating cycle before it finishes. This can be caused by a range of issues, which vary in severity and necessary repair.
Replacing a Thermostat. You'll pay between $15 and $300 for the unit in addition to labor ($65 to $100 per hour) to replace an old thermostat with a new one. However, installing a brand-new thermostat is more involved and, therefore, more expensive.