If you have noticed that your home is not feeling as cool as it should, you may have gone outside and looked at your central A/C unit, only discover that the fan is either rotating slowly or not at all. Besides the fan's motor being burnt out, there are a couple of reasons why the fan is behaving this way.
1. Fan Belt Is Either Stretched or Broken
One reason why your air conditioner's fan belt is not acting right could be that there is something wrong with the fan belt. It may have become stretched after prolonged use and rapid temperature changes. Or, it may have broken partially or completely.
If the fan belt is stretched, you may hear either an intermittent or constant high-pitched squealing sound. Also, in this case, the fan may rotate off and on as part of the belt engages with the pulley.
If the belt is partially broken, you may hear a flapping noise while the fan rotates erratically. However, if the belt is completely broken, the fan will not be moving at all. While you may be able to replace the fan belt yourself if you know what you are doing, taking apart the A/C unit is often not advisable as it could null the terms of the warranty.
2. Capacitor Has Gone Bad
If you do not believe that the fan belt is causing the issue, another possible reason why the fan is not working is that the capacitor has gone bad. The job of the capacitor is to store the power necessary to keep the fan moving. Normally, enough energy is stored to keep the fan moving whenever the compressor kicks on.
However, if the capacitor has burned up or is malfunctioning, it will not store enough power. When this happens, the fan will not rotate at the revolutions per minute required to pull air through the system.
As the part continues to fail, the fan may barely move as it rotates, which could possibly cause problems with the compressor within the unit. If you suspect this is the problem, do not attempt to replace the part yourself.
Whatever the reason, if your air conditioner's fan is either working sluggishly or not at all, you need to have it fixed as soon as possible to avoid future problems. Contact an HVAC contractor who offers A/C system repair services to have them inspect your unit and discuss your options for getting the fan working properly once again.