If the contactor is faulty or worn out, it might not send the necessary voltage to the compressor, even though the fan receives enough power to run. This can create a scenario where the fan kicks on, but the compressor remains idle.
If the AC compressor is not working but the fan is running, potential causes include a faulty capacitor, electrical issues, low refrigerant levels, or compressor failure. It's best to consult a professional HVAC technician to accurately diagnose and repair the problem.
You'll want to have the unit examined for signs of a blown fuse, tripped circuit breaker, broken thermostat, or dirty air filters. Dirty or clogged filters commonly make AC compressors stop working. When it comes to operating your cooling system properly, be realistic with the temperature setting on your thermostat.
One common reason is a dirty or clogged air filter, which restricts airflow and reduces the system's efficiency. Low refrigerant levels can also cause the AC to struggle in reaching the desired temperature, as it affects the cooling process.
As far as the fan running but not the compressor, that is absolutely possible. Usually when that happens it is caused by one of two things, a bad capacitor or a bad contactor. The capacitor gives the unit extra power needed when starting. It may have more than one capacitor.
The main reasons your AC unit outside is not turning on could be something that has tripped the circuit breaker, something is blocking the fan's airflow, or the condensing unit is damaged. Other potential issues could be the thermostat isn't set correctly or the compressor could be malfunctioning.
The fan will only be circulating the heat, though. If you only have a broken compressor, the rest of your air conditioner may be working without a hitch, including the fan, coils, and air filtration system. You could even keep using your HVAC for the fan component without damaging the unit.
Reasons Why Your AC Compressor Has Stopped Working
It is important to examine the unit to find the problem. Some of the common issues include tripped circuit breakers, broken thermostats, dirty and dusty air filters, or a blown fuse. Clogged or dirty filters often cause an AC compressor to stop working.
Most air conditioners come with a reset button attached to the compressor unit. Typically, it is a red button and is very visible to an onlooker. To reset your air conditioner, all you have to do is press the button, and you won't have to worry about all the heavy lifting.
The contactor regulates the power flow to your compressor unit. If it's malfunctioning, this explains why your compressor isn't getting power. The only way to be sure that this is the problem is to check the contactor's voltage.
Overheating is a common cause of compressor failure, and there are many factors at play. If direct sunlight falls on your outdoor unit and there is inadequate ventilation around it, it makes your unit's compressor overheated. High voltages can also damage the motor causing the compressor to overheat.
Set your multimeter to continuity and place the pins on the contacts. Setting the dial on your multimeter to continuity will test if current is properly running through your compressor clutch. Replace the coil if the reading is below 3 ohms or above 5 ohms.
Check Your Power. If the compressor is not working in your AC unit it could be because it has no power. Check your fuse box to see if a fuse is blown or if the breaker has been tripped. Most fuse boxes have tags that tell you what fuse or breaker delivers power to your AC unit.
If your AC capacitor is bad, you may notice that your air conditioner takes a long time to turn on or doesn't turn on at all. In some cases, the damage to the air conditioner's capacitor may be severe enough to prevent the compressor from starting at all.
On average, AC compressor costs range from $800 to $2,300, with most folks paying $1,200 for a new one. However, your price will vary depending on factors like the size and brand of your compressor. Before you schedule your replacement, read on to learn about all AC compressor cost factors.
While your AC fan may continue to run if the compressor is bad, this doesn't mean your system is functioning properly.
A sure sign of a bad AC capacitor is a humming sound from within the access panel. Any humming noises indicate a problem with the air conditioning system or the components of the AC unit. Try turning the power on and off again to see if it was a one-time issue with the motor or a recurring problem.
Some of the obvious signs of a bad compressor include loud noises coming from the unit, water leaks around it, and reduced airflow. To fix the problem, some choose to replace the compressor, while some prefer to replace the entire unit.
The contactor is a small electrical component within your outdoor AC unit that controls the flow of electricity to various parts of the system, including the compressor. If the contactor is faulty or worn out, it might not send the necessary voltage to the compressor, even though the fan receives enough power to run.
Faulty Air Conditioner Capacitor
The starter relay moves that power to the compressor from the capacitors. If your compressor isn't working but the fan is,you may have a faulty capacitor. This is a common and fairly simple problem, but it's important to leave this repair to a qualified and experienced HVAC technician.
Your air conditioner has a fan that turns on/off with the compressor. However, you can select “Fan Mode” so the fan stays on even if the unit isn't cooling your home. Either way, the fan will blow to circulate air. The AC fan is an essential part of your air conditioning system.
1> Listen for the Compressor: When you turn on your AC, listen for a distinct humming sound near the outdoor unit. This sound indicates that the compressor is running. If you don't hear anything, it might not be functioning. 2> Check Airflow: Stand near one of the vents inside your house while the AC is running.
If the Freon levels are too low, the clutch will fail to engage which means there's not enough refrigerant for the compressor to pressurize. In other words, your air conditioning system has nothing to work with!