Your window air conditioning unit has stopped working, and you suspect that there must be a problem with the fuse. However, you couldn't locate it. We did some research on the topic, and in this post, we'll help you find the fuse and fix your AC in no time!
You should locate the disconnect or switch box on the air conditioner—it contains the controls of the main energy supplier such as your fuse. Open the disconnect box. Another cover will be protecting the wirings inside, and you should pop this one out as well. You should now be able to see the fuse.
Typically, a fuse used for ACs will look like a small cylinder with a copper coating on both ends and some electric load information on the center. Now that you have located the fuse, you might be thinking it is time for you to check if it is the one causing problems in your unit. Check out the rest of the article to learn more!
What Is A Fuse?
Window air conditioners usually have an internal fuse for protection. It protects the condenser from being exposed to excessive amperage. They are designed to handle a limited amount of amperage, so when more amperage goes through, the fuse will blow to protect the condenser from overheating.
How To Check For A Blown Fuse
The first given sign of a blown fuse is buzzing, humming, or any noise. This is your furnace trying to convince your air conditioner to turn on when in fact the unit is already inoperable.
However, the best way to check for a blown fuse is with a voltmeter. If you think you’re better off calling an HVAC professional to do the job, then that is the safest bet. But if you already have basic knowledge of air conditioner circuits and would like to save some bucks, then read on, because we will guide you through the whole process.
Using A Voltmeter
A fuse is “blown” when it fails to conduct current from one side to the other. The unit won’t function until the connection is restored.
To execute a voltmeter test, follow these steps:
- Locate your fuse. As mentioned earlier, it should be inside your disconnection box. The disconnection box is usually gray and mounted near the unit.
- Open the disconnection box to expose the wires inside. Locate the incoming line wires and the outgoing load wires. Remember, you are working with high voltages, so take extra caution.
- Make sure that the voltmeter is operating in good condition and a zero volt should be displayed.
- Test the incoming line wires that bring in electrical power to the AC. The reading must be around 220 to 440 volts to assure that problem isn’t with the power supply.
- Test the outgoing load wires. If the reading is zero, your fuse is blown and you might need to replace it. Otherwise, your fuse is working, and the problem might lie somewhere else.
What If I Don’t Have A Voltmeter?
Don’t worry if you do not have a voltmeter. There is another way to check if the fuse is blown.
First, check the volt capacity of the old fuse, then purchase a new one with similar specifications. Replace the old with the new one and if your unit works, then the fuse was definitely blown.
How To Remove And Replace AC Fuses
Now that you have checked and confirmed that your fuse is indeed blown, you are going to need to replace that fuse to restore the unit. We recommend hiring professionals to do the work. But if you want to learn how to do it yourself, just follow the steps below:
- Shut down the breaker to cut the energy supply to the unit. This is for your maximum safety.
- Locate the disconnection box where your fuse is.
- Some fuses are in the same location as the wiring, readily exposed. However, many have fuses in the handle. If this is the case, pull the “T” handle out to expose the fuse.
- You can simply pull the fuses right out with your hands if they are already in the handle. If not, grab a pair of pliers with insulated handles to remove the fuse.
- Install the new fuses, reassemble the disconnection box, and turn everything back on.
Check out this video for a step-by-step guide on replacing a fuse.
Additional Reminders And Tips For Replacing A Blown Fuse
Replacing a blown fuse is simple. It may take you a few minutes to complete the job, but here are some important reminders and tips for you.
- Before checking the fuse, make sure both your hands and feet are dry. This includes the floor you are working around too!
- Do not proceed unless you have completely shut down the breaker to your air conditioner for your maximum safety.
- Take a photo of the disconnection box after you open it. This way, you have a visual guide on the correct placement of your wires and fuse. Once you are done with the replacement, you can verify if you have placed the wires and fuse where they should be.
- If you encounter recurring problems with the fuse, there might be another root cause for this.
- It is always best to contact your HVAC professionals to have your units checked and repaired. They can easily track down the problems and solve them in no time.
How Much Does AC Repair Cost?
The national average for repairing an AC unit is $388. Although the cost for AC repair typically costs $168-$611, there are a lot of factors that affect the cost of your AC repair. In the case of replacing a fuse, here are the things you need to consider.
Troubleshooting And Diagnostics
Troubleshooting service varies from $75 to $180 depending on your location and the peak seasons. HVAC professionals charge a premium during hot summer months too—as much as $200 per hour.
You may also prefer to perform yearly maintenance of your units to keep them in good running condition for around $80 to $100. This way, you’ll have peace of mind throughout the year and avoid major repairs to your system. It also has considerable savings in the long term.
AC Fuse, Circuit Breaker, Or Relay Replacement
Replacing your AC fuse, circuit breakers or relays cost between $15 to $300. These projects are fast and usually take just a couple of hours to complete.
AC Repair Cost By Unit Type
There are different types and sizes of air conditioners, and the cost of their repairs varies accordingly. On average, you can expect to pay between $50 to $125 to repair a window air conditioning unit.
Repairing a window air conditioner is generally cheaper than other bigger units such as central air conditioning units.
During regular business hours, HVAC technicians usually charge $75 to $150 per hour. Expect to pay higher charges for emergency after-hours and holidays ranging from $160 to $250 per hour. Companies also charge a service call fee which is the cost to send someone out and diagnose the problem and runs between $75 to $200. However, this can be waived if you decide to have your units repaired with them.
DIY vs. Professional Repair
You should be able to take care of small repairs if you are an experienced DIY-er. However, if there are electrical works involved, it is best to call in your trusted HVAC professionals.
More importantly, if the problem involves working with refrigerants, always refer to the pros, as this requires a license to handle. Refrigerants are toxic materials that not everyone is allowed to play with.
To Wrap It Up
A fuse is a handy-dandy tool that protects our valuable appliances from unnecessary voltage surge that may cause substantial damage. They are cheap and widely accessible.
Always make sure that your fuses are in good condition. Remember that is cheaper to replace a busted fuse than a busted AC.
If you're ever unsure about diagnosing your AC problems, call your local HVAC professional. They might be able to give you some valuable tips for preserving your AC.
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