April 1, 2016

A central air-conditioner is an elaborate system that involves parts such as an evaporator, a compressor, a condenser, fans, and refrigerant to run through the unit. Like many household appliances, each of these components does their job both independently, but also in unison with the connecting parts and when one section of the system goes down, the entire performance falters. This article outlines what to do if your AC unit is malfunctioning.

While each component in a central air-conditioner is critical, quite simply the unit will not work if the fan is not running. Fans in the central A/C both pull air out of the room to be conditioned and have humidity removed and also push chilled air through the vents throughout the house. When the fan goes down there is no way to cycle the air and thus the system is essentially stalled. It’s important to get the fan up and running ASAP or else the home will get uncomfortable in a hurry and you could end up damaging the compressor.

Symptoms of a Central A/C Fan Not Working

There are a few ways to tell if your A/C fan is temporarily or permanently out of order. The first is an inspection of the outdoor unit to physically see if the fan is turning. The condenser lines should be cold and the air inside the home should be cool. If the fan isn’t running at all or there is warm air blowing it’s time to troubleshoot:

The Fan Doesn’t Start At All

If the fan doesn’t start up at all it could be something as simple as a setting on the thermostat. Make sure that the power is turned on and that the settings are calling for ‘cooling’. If all the settings are correct but the fan doesn’t start it could be an overheated or damaged fan motor.

Fan Has Trouble Starting

In some cases, you can give the fan a ‘kick start’ by pushing it with a stick and if this occurs there is likely an issue with the capacitor. Similarly, if a fan won’t turn when the power is on but will rotate freely when shut off it could be the sign of a bad motor bearing. Trouble with the bearing will also result in wobbly or lopsided turning if the fan does run.

Fan Runs Really Slow

The fan needs to run at an optimal speed for the system to function properly. If the blade turns noticeably slower there may be low voltage running to the unit caused by issues with the control board or problems with the circuits. Also, the fan blade may have come loose from the motor shaft and is simply moving slowly because of a breeze or the turning of the shaft. Once again a capacitor may also be causing issues with the slow-moving fan.

Fan Starts and Stops Intermittently

If your Central A/C fan is acting unpredictably, starting on and off at random and shutting down in the middle of a cycle it could be a sign there’s an issue with the wiring or some loose components somewhere.

Fan Won’t Stop

It’s normal for a fan to keep running for a short time after an A/C cycle while the compressor motor stops but a fan that keeps winding excessively there are likely problems in the circuit board or with the wiring.

Noises Coming From the Fan

As long as the A/C unit is running properly some homeowners may be willing to ignore a ticking, rattling, or buzzing coming from the fan area. In reality, it’s best to diagnose these sounds to make sure they aren’t leading to serious problems down the line. The first thing to check is that an obstruction isn’t hitting the fan blades as they turn or that the blades aren’t bent. Buzzing and humming are somewhat more sinister as they could present a problem with the motor or the bearings turning the blades.

The common denominator with all these problems is that, although a visual inspection might locate the problem, the fix should almost always be done by a professional HVAC technician. It’s better to spend money on a service call and be guaranteed you fix the problem rather than buy unnecessary parts or do incomplete fixes that could end up costing more in the long run.

Are you in Pennsylvania and need help with your HVAC system? Contact us today for a free quote!

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