Why does treadmill goes up on inch and then right back down

How long have you let it run for after turning it back on ? Some treadmills have a re calibration test built in and will incline to the max and work its way down. During this time you should simply walk away and not touch anything as it trys to calibrate its self. If not i will need more information on it

1. Power

o 1

Ensure that the treadmill is plugged into a grounded outlet using the correct surge suppressor. Use a UL 1449 suppressor listed as a transient voltage surge suppressor (TVSS). It must be rated for 15 amps and 120 volts AC. Secure the services of an electrician if the outlet is not grounded, or move the Proform treadmill near a grounded outlet. Do not use an extension cord.

o 2

Insert the safety key fully into the display. Treadmills with keys are designed not to turn on without the safety key in place.

o 3

Find the circuit breaker on the front of the frame and make sure it is not tripped. The circuit breaker is a vertical switch on the 540S and a horizontal switch on the 540 Interactive Trainer. Press it to the "Reset" position, which will be labeled.
2. Reed Switch

o 1

Unplug the treadmill and remove the safety key.

o 2

Move the upright base of the treadmill down with the help of another person and lift the uprights so that you can get to the underside of the console. Use a Phillips screwdriver with at least a 5-inch shaft to remove the screws. There are five hood screws on the 540 Interactive trainer and four screws on the 540S.

o 3

Remove the motor hood to get to the small reed switch by pivoting the hood off the frame. Find the reed switch and magnet, which are on the left side of the pulley for both models.

o 4

Turn the pulley with your hand until the reed switch aligns with the magnet. There should be 1/8-inch gap between the two. Fix the distance so that it is 1/8 inch by loosening the reed switch screw and sliding it to the correct distance. Tighten the screw.

o 5

Reverse the directions to put the hood back on and the treadmill upright in the original position.

Cleaning: Remove the covert and spray the Key Pad with special spray( contact cleaner) for to remove dust, etc, very carefully, you mus unplugged the machine.

1) Find the key.

2) Follow this:

• 1

Ensure that the treadmill is plugged into a grounded outlet using the correct surge suppressor. Use a UL 1449 suppressor listed as a transient voltage surge suppressor (TVSS). It must be rated for 15 amps and 120 volts AC. Secure the services of an electrician if the outlet is not grounded, or move the Proform treadmill near a grounded outlet. Do not use an extension cord.

• 2

Insert the safety key fully into the display. Treadmills with keys are designed not to turn on without the safety key in place.

• 3

Find the circuit breaker on the front of the frame and make sure it is not tripped. The circuit breaker is a vertical switch on the 540S and a horizontal switch on the 540 Interactive Trainer. Press it to the "Reset" position, which will be labeled.
2. Reed Switch

o 1

Unplug the treadmill and remove the safety key.

o 2

Move the upright base of the treadmill down with the help of another person and lift the uprights so that you can get to the underside of the console. Use a Phillips screwdriver with at least a 5-inch shaft to remove the screws. There are five hood screws on the 540 Interactive trainer and four screws on the 540S.

o 3

Remove the motor hood to get to the small reed switch by pivoting the hood off the frame. Find the reed switch and magnet, which are on the left side of the pulley for both models.

o 4

Turn the pulley with your hand until the reed switch aligns with the magnet. There should be 1/8-inch gap between the two. Fix the distance so that it is 1/8 inch by loosening the reed switch screw and sliding it to the correct distance. Tighten the screw.

o 5

Reverse the directions to put the hood back on and the treadmill upright in the original position.

http://www.treadmilldoctor.com/SI3-Error-Code-kf

ensure that the speed sensor under the hood is about 1/8 of an inch from the pulley.
Secondly ensure that the wire harness is really snapped together this connector is in the upright leg on the right hand side if you are on the treadmill. you must unscrew the plastic cap and then unbolt the console to get access.

Should be instruction in your manual on how to take it out of demo mode. I believe it is press the stop button and insert the key. Then press the arrow down speed button once and the letter D that was on the display will disappear. You may have other problem like a damaged upright cable.Call the number in your manual for service as you should have a free 1 year warranty.

plug it back in(power cord) insurt key, let the incline go up,then it will go back down on "her" own-do not touch anything, she's teaching herself/going back to school, or they say"calibrating" when she goes back down, it will stop and you will hear a "beep beep" and then your screen will apear,ready to walk-in future IT will do this from time to time, just let her do her thing... a Sears teadmill tech

It needs to be adjusted as shown in your owners manual.
There are two allen screws located at the back end of the treadmill. That's where you adjust it. 3 - 4 inches of slack midpoint is just right

make sure you are not in a program. Can you speed it back up?

I’m happy to help further over the phone at https://www.6ya.com/expert/howard_079189dd4959a511