Why AC Motors Sometimes Overheat

An air conditioner (AC) uses motors to convert electricity into kinetic energy (motion). The motion runs fans that circulate air in the house and help move refrigerants between the inside and outside AC components. These motors operate best within specific temperature ranges. Overheating can damage motors or lower their efficiency.

Below are common causes of overheating of AC motors.


The motor has several moving parts, such as the belt and rotor. These parts should be clean to reduce their friction levels. Dirt and debris that clog the moving parts increase heat generation and the risk of overheating. The dirt and debris also insulate parts of the motor and inhibit heat loss, increasing the risk of overheating.

Inadequate Lubrication

Friction is a major cause of heat generation in motors. Lubrication is a common way of reducing friction and heat generation. The right lubricant also acts as a medium of heat dissipation. You must keep the motor lubricated since lubricants dry out and break down over time, lowering their lubrication efficiencies. Otherwise, your AC motor will overheat.

Poor Air Circulation

The motor's heat must go somewhere to prevent overheating. Air circulating around the motor picks up the heat and dumps it elsewhere. Heat dissipation won't occur if the environment around the motor has poor air circulation, and the motor will overheat. For example, overheating is possible within AC in a confined environment with poor airflow.

Electrical Issues

Some of the motor's heat comes from the electrical friction within its windings. The friction-related heat depends on the motor size and electrical draw, among other factors. The heat generated increases if the motor draws more power than usual, for example, in the case of a short circuit.


The blower motor's temperature hugely depends on its output. The more the motor runs, the more heat it outputs. Thus, anything that forces the motor to run faster or longer cycles increases overheating risk. For example, the AC might overheat if you set an abnormally low temperature during the summer and force it into long cooling cycles.

Wear and Tear

Wear and tear to the motor or its auxiliary parts, such as the belt, increases friction and forces the motor to draw more power than usual. Both issues increase the risk of overheating, as discussed above. Wear and tear is one reason aging systems are more likely to overheat than new ones.

Hopefully, your AC will cool your home without overheating. Contact a contractor if you need help with your air conditioning system. The sooner you fix the problem, the sooner you will enjoy efficient cooling and energy consumption.