If you are sitting in a hot house during the Boise summer, we at Express Plumbing Heating & Air are here for you. You may have heard your air conditioning unit make horrid sounds and had to shut it down. The unit might have been blowing out very little to no air. Perhaps you could see a fan or motor just slowly moving or not moving at all. In any event, we can come out to diagnose the problem and get you back up and running.

Often times, the above issues are signs that the AC unit’s motor needs to be replaced. How does an AC technician replace the motor? Let us tell you what to expect.

Condenser Fan Motor

You can visibly see if your condenser fan is running or not. It is in the outdoor unit and is the big fan at the top. If it is not running and the unit has power, there are a number of things that could be wrong:

  • Not enough voltage at the panel
  • Bad contactor
  • Bad capacitor
  • Fan motor failed
  • Debris blocking the fan
  • Fan is rusted or damaged
  • Loose or damaged bolt within the motor

In this section and in the next, we will be addressing single-speed fans. We will address how we work with multi-speed fans in the ECM section.

After removing the power to the unit, we will drain the capacitor. Capacitors store incredible amounts of electricity and provide a nasty shock. We will remove the service panel and the fan shroud. We will visually inspect the fan for damage or obstruction.

We will then test for 24 volts coming out of the contactor. If so, the contactor is fine, and line voltage is present. Then, we will try to spin the fan blade. If manually spinning the fan blade causes it to work, we will check your capacitor. It likely will have failed. The capacitor gives the fan its initial boost of electricity. If the capacitor is OK, we will electrically test the motor. We will ensure that there was no other cause of motor failure before we replace it.

If the condenser motor is the offender, we will already have the fan shroud off. We will take the fan out with the motor and then remove the motor from the fan. We will ensure we have the exact motor needed so no further problems emerge down the line. We will hook up the motor with the fan, pull off the condensate plugs, fish the wiring back through the service panel, and button everything back up.

It’s often recommended that you replace the capacitor at the same time as the condenser fan motor. After any of these repairs, we will test and inspect the entire system for full functioning.

Blower Fan Motor

The blower fan motor is very large and is usually in a squirrel cage. There is often more for us to remove to even get to the motor and perform electrical testing. We will remove the blower housing once we have removed other wiring or panels. Then, we have to take the motor and blower housing out of the unit for testing.

This fan also has a capacitor that gives some extra juice to start the blower moving and regulate it. We will have to test both the fan and capacitor. If the capacitor has failed, the blower fan was moving but likely backwards. Because the fan was blowing backwards, it was not blowing any cool air. This fan has scoops to move the air forward.

If we find the motor is the culprit, we will again suggest you replace the capacitor as well. It saves a service call later.

We may need to replace the mounts if there is any problem keeping the blower secure. We will then get the fan and motor back in the housing, torque everything down, put the rest of the wiring and panels back in place, and test the full system for proper functioning.

ECM Motor

ECM motors are variable-speed motors found in higher-end air conditioning units. They are also typically more expensive to replace.

Much of what we do to replace a single-speed motor applies to what we do to replace a variable-speed motor. One big difference in how we approach things is with the ECM blower motor. These motors usually have spade terminals. Spade terminals allow us to test the blower electrically without having to remove the blower housing first. We will first reach our hand in the blower and ensure it can spin freely. Then, we will test the spade connectors for full power to the motor. We will also test the speed connectors (different from the spade terminals) for the proper setting that the factory intended. That is the speed at which the fan is designed to turn on.

Some ECM motors have tiny switches that allow us to program them in the field. Some of them need to be programmed in the factory. If there is any problem getting your exact ECM motor in a timely fashion, there are other options. We will inform you of your options if we have any problem replacing an ECM motor. These options often allow us to replace the ECM motor the same day.

Compressor Motor

The compressor motor is a sealed unit. Three terminals allow us to test the motor. We test for proper resistance at two of the terminals and ground at the other. If there is voltage at the ground, the motor has possibly failed. The tricky part is that this unit has a safety switch that toggles on in the event the compressor is about to overheat. We can get a false reading if the safety switch is on. That is why we need to try to get the safety switch toggled off. If a technician is not experienced, the compressor motor could be replaced when it had not failed. We will not replace a compressor motor that is working.

There is an industry-standard diagnostic sequence to find out why any motor is not running. Even if we determine that any of these motors have failed, we also need to know why. There may be something that is causing this failure. We will also use the proper replacement part so that you can rest assured the problem has been fixed right the first time.

We will also do a system-wide test after we complete the repair. We want to ensure that no other problem looms on the horizon. Out of respect for you and your home, we’ll clean up the work area before leaving.

Trusted and Ethical Air Conditioning Repair in Boise

If you are in need of air conditioning repair in Boise, call on us at Express Plumbing Heating & Air. We have been serving Boise and the surrounding area since 2006. We are your heating and air conditioning experts for installations, repairs, and maintenance services. If you need indoor air quality services, we do that too. We clean ducts as well. We are also your full-service plumbing provider. What that means is we also provide drain and sewer services.

Our technicians are highly trained and NATE-certified. We work on all makes and models of heating and cooling equipment. The Better Business Bureau has even honored us with the Torch Award for business ethics. You can count on us to help with all your plumbing, heating, and air conditioning needs.

Call us at Express Plumbing Heating & Air in Boise for help with your AC unit’s motor. We have proven our commitment to high ethical standards.

Brad Jordan

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