The fan in a window air conditioner is what takes in the circulating room air, cools the air, and then pushes that cooled air back into the room. A problem with the fan can render your unit nonfunctional and start driving up your indoor temperatures. Luckily, there are a few common problems that cause a fan in a window air conditioner's fan to stop working.
You can check on a couple of these problems yourself but you might need to leave the complex fixes to an air conditioning service technician. You don't want to mess around with electrical parts unless you have a lot of experience or else you could end up doing more harm than good.
Here are a few of the potential reasons your window air conditioner's fan has stopped working. Note that you will want to consult your owner's manual to figure out how to get the unit open to access the fan, and make sure the unit is unplugged first, if you plan to do these checks on your own.
Dirty or Loose Fan Blades
A common yet easy to fix problem is that the blades have either become so dirty or loosened that the fan isn't able to spin properly. So the fan is technically working but not working well enough to circulate your cold air.
You can conduct a visual inspection of the fan blades for any signs of dirt or damage. You can clean the fan with a clean sponge dipped into a mixture of dish soap and water until lightly damaged. Dry the fan with a microfiber cloth once clean. If you see any signs of damage such as bent or broken blades, you don't need to bother cleaning the blades. Call in an HVAC tech for a fan replacement.
Does the fan look fine? Try turning the fan with your hand. Does the fan spin but wobbles quite a bit? The bearings holding the fan onto the motor have become loose. Use a wrench to tighten the bearings then try the fan again. If it spins easily now without wobbling, put everything back together and test the system to see if the problem is resolved.
Bad Fan Motor
When you tried to turn the fan blades, did the fans spin easily with no signs of damage or dirt? The problem might be in the actual fan motor. If the motor goes on the fritz, there isn't anything moving the fan around so it simply sits still even though there's nothing wrong with the blades.
Call in an ac repair technician to test the fan motor and install a replacement part, if necessary. You don't want to test and take apart the motor on your own if you don't know what you are doing as you could damage a motor that wasn't broken in the first place.
Intact fan blades that spin easily manually are often a sign of a bad motor. But the problem could also be in the control board and its relays. This is again a problem that you want to leave up to an air conditioning repair professional. Depending on the original cost of your window air conditioner, it might prove less expensive to simply buy a new unit rather than having a new control panel installed. Visit http://www.advancedheatingandcooling.com for more information.