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When Capacitors in an AC Go Bad

air-conditioning-maintenance-toolsYou might have read that headline and immediately had an image of a capacitor pulling a handkerchief over its face and trying to hold up a stagecoach with six-shooters. Or maybe you didn’t imagine that—because you have no idea what a capacitor in an air conditioner looks like!

That’s fine. Most homeowners aren’t aware of what a capacitor looks like or what it does in an air conditioner—although they’ll know they don’t want one to “go bad.” We’re going to delve a bit more into air conditioning capacitors and the problems your AC may face when they fail.

Capacitors Are Essential Electrical Components for an Air Conditioner

Many electronic devices use capacitors. In an air conditioner, the job of a capacitor is to send voltage to the motors powering the compressor and the two sets of fans necessary for the cooling system to operate. “Start” capacitors send the volts to start up a motor, and “run” capacitors provide continuous volts to keep the motor running. (Nice how precisely they named them!)

A capacitor may start to lose its ability to hold an electrical charge—especially after long exposure to summer heat—eventually leading to it failing altogether. This is what we mean by a capacitor “going bad.” If any of the capacitors in your AC fail, the system’s performance will suffer and it’s likely the air conditioner won’t work at all. One example: If the compressor won’t start because the motor isn’t receiving voltage from its start capacitor, then the air conditioner will not be able to cool the house.

Signs of Failing Capacitors

You want to catch early indications of a failing capacitor so you can have professionals fix the problem before the AC fans shut off or the compressor stops. One sign to watch for (actually, listen for) is a clicking sound from the cabinets of the AC when it starts up or while its running. This can mean a capacitor near failure. Also watch for a “hard-starting” compressor, where the compressor has difficulty turning on. There are several causes of hard-starting, including bad capacitors, but none of them are good and you’ll want the trouble remedied as soon as possible.

Fixing Bad Capacitors

Please don’t attempt to fix a capacitor problem in your AC on your own! Tinkering with the electrical components in a complex piece of machinery like an air conditioning system can only make things worse. You may not even know the capacitor is at fault, or which capacitor is at fault.

At the first suspicion of a failing capacitor, call a licensed and trained HVAC technician. They can locate the specific problem. If it is a capacitor, the technician will replace it. (Another reason to never go DIY or trust an amateur with this job: you may end up with the wrong type of replacement capacitor.)

Call us when you need air conditioning service in Durham, NC or elsewhere throughout the Triangle Area. We have NATE-certified technicians to ensure any repair job is done right!

Enjoy the comfort you deserve! Turn to our HVAC experts at Comfort Master Heating & Air Conditioning, Inc.

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