Belt Won't Spin On My C800

If the belt is too tight, it could cause enough tension that the motor can't turn the belt. This is most likely the cause of your belt not moving if you recently adjusted the belt tension due to slippage. Lift the edge of the belt. If you can't raise it at least 2 to 3 inches off the walking deck, the belt is too tight. Follow the directions in your owner's manual for loosening the belt. You will need an Allen wrench to loosen the rear roller adjustment bolts.

A treadmill belt can shift to the right or left over time. If it shifts enough, this may cause the belt to stop moving. Stand at the back end of your machine and inspect the belt. If it has shifted, you will need to center it by turning the rear roller adjustment bolts. These bolts adjust both the tension and the centering of the belt. Follow the instructions in your owner's manual that explain which of the two bolts you need to tighten or loosen to shift the belt back to the center.

Horizon Fitness recommends checking the console wiring if your treadmill belt doesn't move. The console wire connects to the main wire that runs down the inside of the treadmill upright to the motor board. Make sure the connection between the two wires is secure. The connectors usually snap into each other. Disconnect and reconnect the wires. Make sure the wire that runs through the upright isn't pinched or twisted.

https://www.livestrong.com/article/406534-the-treadmill-belt-wont-move/

Thanks

Motor control board may have failed, and yes, there are speed sensors on ALL Icon branded treadmills that use a DC motor as a drive system. AC Drive systems use vector management but most all DC motor systems still use a sensor for regulations of speeds. ;0)

If an icon treadmill has an open speed sensor, that belt will still move when you press start, it simply will not run the correct speeds and may act oddly. Other brands of treads will also run with open speed sensors for 1-3 seconds then error or stop.

Good Luck