Is My HVAC Fuse Blown?

Indoor Air Quality in O'Fallon, MO

Your heating, ventilation, and air conditioning (HVAC) system requires power to run. Normally, HVAC fuses protect your system from damage due to excessive amperage. Each fuse can only handle a certain amount of amperage. If the electricity level increases too much, the fuse will blow.

While this is frustrating for homeowners, the blown fuse is actually a good thing. By blowing, the fuse causes your HVAC system to shut off. The fuse is a fail-safe mechanism that prevents high amperage from damaging your HVAC. Once you notice common signs of a blown fuse, the next step is figuring out the underlying cause. To do this, you should call an HVAC technician to diagnose and repair your HVAC system. With the right repairs, your air conditioner or heater can run properly again.

What Are the Most Common Signs of a Blown HVAC Fuse?

You’ll quickly notice a blown fuse because your HVAC system suddenly stops running. There are also a few other signs of a fuse-related problem with your HVAC system.

Burning Smells

One of the first signs of a blown fuse is the smell of something burning. This smell can come from the furnace, air conditioner, or heat pump. If they keep functioning after a blown fuse, the lower electrical flow will cause these devices to work harder. As a result, they can overheat and create a burning smell.

Lack of Cold or Hot Air

Your HVAC system is designed to heat and cool your home. If you’re not noticing a lot of hot or cold air, it may indicate that a fuse has blown.

You can also test this theory by changing the temperature on your thermostat. Something is wrong if the air conditioner or heater doesn’t kick on. There may be a faulty compressor, electrical malfunctions, or other problems. Because so many causes could be responsible for this issue, it’s important to arrange for professional HVAC repairs.

Unresponsive Controls

This goes along with the previous symptom. If changing the fan speed, temperature, or HVAC mode doesn’t cause the system to react, you may have a blown fuse. These parts need power, so a blown fuse will stop your HVAC system from responding.

Burned Fuses

Another way to tell if you have blown fuses is by looking at the fuses. If one has been blown, it will look like it was burned or melted. This happens when the fuse has been overloaded by electricity. You can find blown fuses in your fuse terminals or the fuse box.

Tripped Breakers

Tripped breakers are a safety mechanism designed to protect your HVAC system from damage. If your breaker keeps tripping, it is an indication that there is some underlying electrical issue. A blown fuse is just one potential cause of this issue.

Warm Air From Your Air Conditioner

Sometimes, HVAC systems have different fuses for protecting indoor and outdoor units. If your air conditioner is blowing only warm air, there may be a blown fuse in the outdoor unit. This blown fuse is preventing the outdoor unit from getting enough power. The inside portion of the system is still running, which is why it can blow warm air out. Once the relay fuse is replaced, your unit should start working again.

Causes of Blown HVAC Fuses

At Hoff Heating & AC, we have years of experience diagnosing HVAC problems. If you’re dealing with a blown fuse, our HVAC maintenance and repair services in O’Fallon can help you diagnose the underlying cause and find the best possible solution. Typically, blown HVAC fuses happen for one of the following reasons.

Faulty Capacitor

The capacitor is responsible for starting the compressor and fan motor. It stores and releases a huge amount of power. When too much power is released, it can cause the fuses to blow.

A faulty capacitor needs to be replaced by a professional. Because of the high voltage involved, it is too dangerous for an average homeowner to fix.

Overworked Air Conditioners

On especially hot days, an air conditioner may blow fuses. An overworked air conditioner can also happen because of clogged air filters, blocked ducts, and low refrigerant. If the air conditioner is sized incorrectly for your home, it may blow fuses.

Faulty Electrical Wires

An HVAC unit may frequently blow fuses if there is an issue with the electrical wiring. Over the years, the electrical wires can gradually become worn out and damaged. As a result, they may develop short circuits or become overloaded. Other than blowing fuses, faulty wiring can also lead to electrical fires.

Broken Compressors

The compressor is responsible for circulating refrigerant. When the compressor draws more power than intended, the fuses can blow. This typically occurs if the compressor is faulty.

How to Fix Blown HVAC Fuses

The method for fixing a blown fuse depends on the underlying issue. Depending on the cause, you may use one of the following solutions to fix your blown fuse. Only the first one can be done by the homeowner. The rest require a professional technician.

These are possible solutions for a blown fuse:

  • New air filter
  • Compressor replacement
  • Electrical wiring replacements
  • Evaporator coil cleaning or replacement
  • Capacitor replacement

If the only issue is a blown fuse, the HVAC technician may simply replace the fuse. However, they may need to replace other parts if there is a faulty component. Likewise, the technician may need to clean the evaporator coil and filters if these issues are causing the HVAC system to be overworked.

How to Prevent Blown Fuses

A blown fuse indicates that your HVAC system is pulling too much electricity. Something needs to be cleaned or repaired to solve the root cause. After you’ve replaced the blown fuse, there are a few things you can do to prevent issues in the future.

Replace HVAC Filters

While each brand is different, HVAC filters should generally be changed every one to three months. A dirty filter can cause your HVAC system to work harder than it should.

Get Regular Maintenance Checks

You should generally get two HVAC inspections per year. An HVAC technician should inspect your air conditioner unit in the spring before the weather becomes warm. Then, they should return in the fall to inspect your heater before the weather gets cold.

During these inspections, one of our HVAC technicians will look for faulty parts, worn electrical wiring, and other problems. They will also clean dirty components and lubricate all moving parts.

These inspections are important because the HVAC technician can spot problems before your system breaks down. When you have a dirty or faulty part, it puts extra wear on your system. Getting these issues fixed early can prevent a faulty component from causing additional problems.

Discover More Information About HVAC Maintenance and Repairs

At Hoff Heating & AC, we help O’Fallon residents access the best heating and air conditioning services. Besides HVAC repairs, we can install whole-home air purifiers, dehumidifiers, and humidifiers. We work with all heating and cooling systems, including mini-splits and geothermal systems.

To learn more about our services, contact one of our team members at Hoff Heating & AC today!