There are two settings on your thermostat to control the fan – auto or on. AUTO means that the fan turns on automatically only when your system is heating or cooling air. Once the thermostat reaches the desired temperature, the entire system shuts off until the next cycle.
There are two power switches associated with most central air conditioners. One switch powers the indoor unit, and the other powers the outdoor unit. Both switches need to be in the "on" position for your AC to work. Typically, you can find the switch for the indoor unit near your system's furnace or air handler.
An electromechanical thermostat typically contains either a bi-metal coil or a metal strip. When the temperature changes, this coil or strip will move, causing a vial containing mercury to tip to one side. The mercury flows to one end of the vial, signaling that the heating or cooling needs to be turned on.
Yes, a malfunctioning thermostat can indeed cause the fan not to work properly.
In normal operation, when your thermostat is set to "auto," it will tell the blower fan plus the heating or cooling components to turn on and off at the same time when the desired temperature is reached. In many systems, the blower fan runs a minute or so before heating or cooling begins and ends to get air flowing.
Your radiator fan should kick in at about 200 degrees Fahrenheit. If you notice your vehicle is overheating or at the very least running hotter than it normally does, listen for the fan to see if you can hear it.
The Fan Won't Come On
A sure sign of a bad fan motor is a cooling fan that will not come on. The cooling fan should spin continuously during operation. You may hear a slight buzzing sound from the fan, but the fan will not turn at all if the motor has failed.
The blower helps circulate hot or cold air throughout your home until the temperature on the thermostat is reached. There are two settings on your thermostat to control the fan – auto or on. AUTO means that the fan turns on automatically only when your system is heating or cooling air.
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.
A thermostat is responsible for turning on and off the air conditioner's compressor and fan. The thermostat senses indoor temperatures and uses this data to determine when the rest of the HVAC system needs to run and when to stop; i.e. it's a switch connected to a temperature sensor.
As the engine reaches its operating temperature, the thermostat gradually opens, allowing coolant to flow to the radiator.
Thermostat Auto Mode
Whenever your thermostat reads that the actual temperature inside of your home is above 78 degrees, it will automatically turn on your air conditioning system.
If your thermostat is set to cool but your AC isn't turning on, there could be several potential causes ranging from a simple tripped breaker to more complex refrigerant or compressor issues. Start with the basics, like checking the thermostat settings and power supply, and work through more detailed troubleshooting.
First make sure there is power to the indoor unit and that a switch or breaker isn't off. Some indoor units (Heat Pumps) have breakers right on the Air Handler itself. But also check the main breaker panel. Some units have a shutoff switch on the side of the unit or an Emergency Switch located on a wall.
For all the upsides of a constantly running fan, there are some downsides. The most significant is the increase in energy usage and the subsequent higher bills. When you're trying to cut expenses, keeping the AC fan on 24/7 isn't helpful and will probably cost you more.
Turn on the heat on the thermostat and increase the temperature. You should hear a sound from both the thermostat and the furnace, and whichever doesn't make a sound has a problem.
First, check your filters and coils for dirt and debris that may be impeding airflow. Once you've cleaned the filters and coils, run the air conditioner with just the fan so that the ice accumulation can melt off. If the AC still doesn't blow cold air, it could be that refrigerant levels are too low.
In most vehicles, the radiator fan is programmed to turn on when the engine coolant reaches a temperature between 200 and 230 degrees Fahrenheit (93 to 110 degrees Celsius). However, some vehicles may have different temperature thresholds for the radiator fan to activate.
By using the fan, the Ac need not be on a very cold setting which costs more money. Conclusion: Using Fan along with air conditioner results in the following: Faster cooling – Fan helps to cool your home faster.
An outside AC fan not spinning could be caused by power supply issues, a faulty capacitor, a burnt out motor, contactor issues, wiring problems, debris or obstruction, a faulty thermostat or control board, or frozen evaporator coils. Contact your local Carrier dealer to help troubleshoot the issue further.
There are a few methods to test the radiator fan, with varying effectiveness. You can use the car battery to test the cooling fan for issues. You can also check the fan's commutator for open circuits. If it stops on a “dark” spot, the fan won't run then and the problem will be intermittent.
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.