Can I Still Use My A/C With a Bad Capacitor?

A Common Air Conditioner Problem in the Sacramento Valley

Every spring and summer, we get a lot of phone calls from customers saying their AC isn’t working.  A good portion of those calls are for a common repair.  Their capacitor has failed.  If your technician has told you that your capacitor has failed, it’s definitely one of those items you’re going to want to replace. And I’m going to tell you why in this post.

Fair Warning

I want to give a fair warning to everyone watching this.  If you’re reading this with the intention of changing your own capacitor, they carry a lot more voltage than the typical 240 volts that runs the air conditioner.  Capacitors can and will shock you even when the power is turned off.

Serious injury and death can occur, as high voltage doesn’t mix well with the human body.  So this blog post is not meant to teach anyone how to install or replace a capacitor.  There are other YouTube creators that will explain it for you.  I recommend having a real HVAC technician handle this repair as that person will know how to discharge the capacitor properly so no one gets injured.

What is a Capacitor?

A capacitor is a storage bucket of electrons that is constantly giving itself up for the motor it supports.  And, they don’t make them like they used to!  Capacitors made in the 60’s 70’s and 80’s were designed to last a long time.  As a technician, I still come across these late model air conditioners and I’m amazed their capacitors are still running just fine.

That’s unheard of these days.  Capacitors made today are typically designed to last five to ten years.  There are definitely some brands of capacitors that are made better than others, and it’s up to your HVAC technician to find those good brands and use them in the best interest of you, the customer.

Frustrations

I’ve seen caps that only lasted two years!  I know of certain brands of air conditioners that are installed brand new, and two or three years later, we are replacing the capacitor.  Then an HVAC company comes out and replaces theirs with a cheap or less proven brand, and it gives out in a short amount of time, with no warranty on the item.  So the customer has to buy another one.  That’s frustrating for the customer, but not for the HVAC company. They get to keep charging $200+ to keep your AC running every other year.

We use MARS brand capacitors, because they are made in America and I personally believe they last longer than the others.  There are several other brands to use out there, but we don’t switch it up and use those other brands just because we happen to be near an HVAC supply store that sells cheaper capacitors.

A Dead Giveaway

Most of the motors in your air conditioner can’t run without a good capacitor.  Like I said, they support these motors.  They help the motor start and run efficiently.  Some people have gone out to their air conditioner and noticed the fan wasn’t spinning on their AC like it should be.  So they get a stick or something to reach into the fan shroud and try to manually get the fan blade to start spinning.  And it works now!  This is a classic sign that the capacitor for that fan motor is bad, and a good example for you that demonstrates why these motors can’t start and run efficiently without a good capacitor.

And we can’t just put any old capacitor in there, because it needs to be the exact size recommended by the manufacturer.  If it isn’t, the motor might start, but will operate out of balance. It causes an uneven magnetic field around the motor, which can make the motor noisy, make it work harder (raising the cost to run it,) or just cause the motor to burn out altogether.

Other Complicating  Factors

There are differences in a typical dual run capacitor that normally comes in your AC and a start capacitor that can be added onto your system either by the manufacturer or at your house by a technician.  I’ll explain those in a different blog post and video when I make them at a later date.

But for the purposes of this blog, I wanted to answer a question recently posed by my best friend Matt.  It’s actually an excellent question to answer for other people out there.

If your capacitor has failed, please don’t try to run that part of the system.  It’ll only cause more damage to the system, which might force you to replace a bigger, pricier part, or your entire system.  So just be patient.  Hopefully your technician has one on their truck already.  They usually will.

Use Caution

Some of you folks out there changing these out on your own better be careful.  Capacitors carry a lot of power and will strike before you know it.  So, that’s just my last bit of warning for you DIY’ers if you try to navigate this repair on your own.

If you are buying these parts online because of price, they might be cheaper, but that’s nothing compared to getting injured or possibly ruining a more expensive part because you didn’t hook it up right.  If you’re paying the average price of $100 to $300 dollars for a capacitor from your technician, (depending on which part of the country you’re in,) it’s because you’re paying for that company to have the right one on their truck and install it right now for you.

Thanks for coming by and we’ll see you on the next post.

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