Possible Solutions to Proform Error Code 21 Problem

Mar 02, 2020

Error code E21 on Proform treadmill indicates the console is not receiving information from the speed sensor on the front roller. The motor will start, and when the console does not receive the signal that the front roller is turning, it shuts the treadmill off.

First, determine if the motor is turning before you get the E21 or not. If the motor turns, the speed sensor is the most likely problem. If it does not, you can manually turn the belt with your feet before you get the E21 and you should get a speed reading but eventually you will get an error code because it is almost impossible to keep the speed constant enough for the computer.

Try running it through calibration with the motor cover removed. Most that give an E21 message have either a MC-54, MC-70, MC-2000(H), or MC-2100 controller. If it doesn't run in calibration, make sure the PWM LED is flickering on the power board in the motor area when the duty cycle is set to 85 (the instructions will make this step more clear). If the motor does not run, test the motor with a cordless drill battery. If the motor tests good, the wiring is good, and it still won't run in regular operation of the treadmill, the controller is out and you need a new one