Your AC's blower motor is responsible for moving air through your air conditioner to cool it and then pushing it back out into your home. Without this incredible component, your AC can't provide any cooling effect, no matter how much the compressor runs.
If your blower motor starts to go out, it can cause the rest of the system to overwork and heat up.
If the motor is making rattling, clanking, or banging sounds, it may be because of a loose or broken part inside the system. Loud banging sounds are especially worrisome. They're usually a sign that something within the system is damaged or disconnected, potentially indicating the need to replace the blower motor.
In short, common issues that can cause an air conditioning unit fan to stop spinning are electrical issues, problems with the capacitor, contactor issues, a burnt out air conditioner motor, a broken fan belt, or clogged air filter.
Most blower motors are controlled by a red or black switch on the side of the unit. Hold the button down for a few seconds (the manual will tell you precisely how long), then release. Replace the Panel and Restore Power.
Recognizing the signs of a failing AC blower motor can help you take prompt action and avoid further damage to your HVAC system. Some typical indications of a malfunctioning blower motor include weak or no airflow from the vents, strange noises or odors, increased energy bills, and HVAC unit overheating.
Blower motors are designed to last just as long as your furnace itself, anywhere from 10 to 20 years. Just as with any HVAC system, the better maintained and serviced your equipment is by experienced HVAC technicians the longer it will last and the fewer repairs you'll face.
The replacement of the blower motor is common and straightforward, so most shops will perform the repair — many on the same day.
However, they can eventually burn out, so if your AC unit's blower motor is old, it might be time for a new one. One sign of a faulty blower motor is an air conditioner that still runs without blowing cool air. Remember: If the blower motor stops working, air is not moving through the system.
A failing blower motor may emit unusual sounds. This may sound like screeching or squealing if it has bad bearings.
It typically takes one to four hours for the technician to replace the AC fan motor. Normally, good technicians will check for other issues during this replacement. If more problems are found, they will be repaired as well.
On some platforms, a faulty blower motor relay will cause the blower not to work at all, which means there will be no airflow from the A/C. On others, the blower won't work on “high blow” but all the other speeds will work. The blower motor relay fails because it regularly deals with high current loads.
Overheating is one of the most frequent occurrences that can render the blower motor inoperative. If the motor has overheated, it may shut itself down to prevent damage. You should keep your HVAC clean and clear of any blockages or debris to avoid overheating and maintain efficiency.
Replacing your HVAC blower motor, which typically needs attention every 10 to 20 years, costs about $560 on average, with most homeowners paying between $300 and $900. Factors influencing the cost include your geographic location, the size and quality of the motor, and labor expenses.
Blower Motor Resistor Test
Typically, if the fan will work on some speeds but not on others, the resistor is suspect. Okay, let's say there's no melting going on, but your fan doesn't work on all speeds. Typically, if the fan will work on some speeds but not on others, the resistor is suspect.
More specifically, systems that include blower motors have a lifespan of roughly: Air-Source Heat Pumps: 10 to 12 years, with a maximum of 15 years or more. Furnaces: 10 to 20 years, depending on maintenance schedules. DX Air Conditioners: 15 to 20 years, depending on maintenance schedules and manufacturer quality.
Some of the reasons a blower motor might fail are overheating, and excessive moisture. When dust, dirt, and debris build up, it can cause the windings and bearings to burn up more quickly.
The motor won't spin – If the rotor that holds the fan blower wheel won't spin or is hard to spin, it's a good sign that the blower motor is shot. Once again, if the motor is getting proper voltage and the capacitor is good, but the blower won't freely spin, it may have seized, which is not uncommon.