Why is my AC Compressor Not Working but the Fan is Still Running?

What is an HVAC Compressor?

The compressor forms an integral part of your HVAC system. Its purpose is to transfer heat out of your home by compressing refrigerant fluid. When the already warm refrigerant heats up further, it is converted from a gaseous state to a liquid form. Heat is always transferred from a warm area to a cool area, which is why the temperature of the refrigerant is always kept higher than the environment surrounding it. To transfer the heat out of the house efficiently, the compressor needs to be kept in good working order. In most cases where the air conditioner has stopped working, the root of the problem can be traced back to the compressor. Regular maintenance will ensure that the compressor is working at optimal levels in order to maintain a comfortable temperature.

A properly working AC will provide cool air for your home throughout the summer by efficiently transferring warm, dry air to the outside. During the intense heat of summer, the worst thing that can happen to your air conditioner is compressor failure. Bearing in mind the amount of hard work an AC has to do, it is not surprising that ultimately something is bound to go wrong with the compressor. Sometimes the fan will still be running even though the compressor has stopped working. This is not a dire situation, so don’t panic. Here are some reasons why this could be happening and how to solve it.

What Could Be the Cause of a Compressor Not Working But the Fan is Running?

When you notice that the fan is running, but the compressor is not working, the problem is usually something simple that can be solved with a quick DIY fix. However, there are certain problems that will need the professional services of a qualified HVAC technician.

• Dirty Coil and Filters
Accumulated dirt and debris on the condenser coil, filters, or evaporators can cause the entire air conditioning unit to shut down. A clogged air filter can reduce the airflow to such an extent that the evaporator coil will stop functioning. Dirt on the condenser coil and filters will cause the compressor to build up pressure, causing it to overheat. In some cases, the compressor will automatically shut down before it can become too damaged. If not, and overheating continues, compressor failure will result, which will necessitate a complete replacement.
If the condenser has shut down, you should clean the condenser coil, replace the air filters, clean out the supply vents and ensure that there are no obstructions or blockages that will prevent the air from flowing freely.

• Capacitor and Starter Relay Problems
Capacitors and starter relays play an integral part in the supply of power to the AC compressor. The capacitor provides power to start and run the blower motor, the outer fan, and the compressor. The starter relay’s function is to transmit the power from the capacitor to the compressor. Capacitor and starter relay are the most common causes of compressor problems. When you turn the AC on, and you hear humming sounds, but the compressor is not working, the most likely reason is that the compressor is trying to access a capacitator that has stopped operating. The good news is that capacitors are the cheapest and easiest parts to replace.

• Dead Compressor
Simple issues like overheating or a faulty capacitor can cause the compressor to stop working completely. The only option for a dead compressor is to have it replaced. This job should only be done by an expert AC technician.

• Power Failure
When the compressor has stopped working, but the fan is still running, the problem may be that there is no power reaching the outside unit that houses the compressor. Because the central unit of the AC is not affected, the fan will keep working.
If the compressor has stopped running, check the connecting wires between the two units. If there is a blown a fuse or the circuit breaker has tripped, you have found the problem. Other problems may include a mismatch between the outdoor and indoor units, a faulty thermostat, or an AC that is just too old.

Here are some situations you may face if the compressor is not working, but the fan is still running:

– Warm, dry air emitting from the fan
– The compressor has stopped working altogether
– The circuit breaker is tripping all the time
– Shaking and strange noises coming from the outdoor unit

The compressor is central to the proper working of your air conditioning unit. If the compressor has stopped working, but the fan is running, it may be time to call in a professional AC technician to assess the situation. An expert can recommend repair or replacement of the compressor before the entire AC unit packs up, leaving you to bear the brunt of the summer heat until it a replacement is found and installed.

How to Prevent Compressor Failure

The best way to prevent compressor failure is regular maintenance since it will solve most problems before they can cause major damage. A compressor consists of several parts that are easy to replace. Regular inspections will ensure that a failing part is spotted early and replaced before the compressor stops working altogether.

An AC compressor that has stopped working can cause major discomfort as well as some concern. If you detect any of the above problems with your AC unit, the best way to prevent further problems is to call an air conditioning technician to check the unit for any problems that can be fixed on-site or to recommend replacing the compressor if necessary.