When starting my treadmill the incline just starts all by itself, all the way up, sounds like it would keep going if it could, then it declines, its stuck in this loop. the belt never starts and I cannot stop the incline/decline loop unless I unplug the darn thing

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwj79pDHxZSCAxV_AHkGHbhiDxkQFnoECBsQAQ&url=https%3A%2F%2Fwww.justanswer.com%2Ffitness-equipment%2Fgdah0-reebok-8000es-treadmill-incline-keeps-going.html&usg=AOvVaw0mEH-BLg44uwLpy6jJGb3K&opi=89978449

You've to check the incline and decline limit switches also the incline motor
If you wish to get some details about treadmill repair and service ; check the site linked here. Pull up older posts.
http://electro-medical.blogspot.com/

Bad contact in the switch

I expect there is a limiter switch that tells the treadmill when it has reached its maximum elevation. The switch is probably either malfunctioning or broke.

RUN the software calibration, for easy diagnose, troubleshooting, and fix it.

God bless you

Double check that all connections are secure, especially the console cable. Unplug and reconnect the console cable to verify.
Unplug treadmill from wall outlet. Wait 60 seconds, allowing lower board to discharge built-up energy.
Remove motor cover.
Verify that there are no lights lit on the lower circuit board.
Verify that all wires are securely and correctly placed on the lower circuit board, especially the large wire harness on the top of the circuit board with 12 different colored wires coming out of it.

I have a Proform ZT5 model - had the same incline/decline problem. It needed calibrated.
- unplug, turn off, and take the key out
- plug machine in
- turn switch on
- Pres and hold the STOP and SPEED UP button at the same time, while holding them insert the RED KEY
- let go of both buttons
- press STOP 1 time
- pres INCLINE UP 1 time
- this should reset it.

The tech on the phone mentioned the importance of turning the maching off, taking the key out, and unplugging after each use. Leaving it plugged in there is still an electrical current running and this can cause more seriouc problems that require a new control panel.

My wife had the same problem with her treadmill. I turned the beast on it's side, and unscrewed the plastic casing that houses the motor, computer, and all the electronics to the treadmill. I unplugged the incline/decline motor. Then on the bottom of the treadmill the long threaded rod that causes the incline needed to be moved. So I unbolted it from the catch, and manually screwed the rod back in with a wrench. Now the treadmill works fantastically, of course the incline/decline mechanism has been disabled, but I would rather have a treadmill with the incline disabled than have one always on 100% incline. Hope you found this helpful :)

i just called the manufacturer on this and found out i have a faulty control panel, but these are the steps they told me to go through to reset. If it works, then you are good, if not, you may also have a control panel issue.
1. plug in and turn on treadmill, keep red key out
2. press and hold the stop button and speed up button at the same time and hold them while you insert the red key
3. after red key is inserted, let go of both buttons
**CAUTION - be sure to stand on side bars of treadmill, clear of the belt for this next part bc it will go VERY FAST***
4. press stop button once
5. press speed up button until it reads 85 (see what i mean?!)
6. press stop button once
7. press incline down or up one time and it should get back into normal mode. mine just started a series of flashing lights and "8"s in all the "windows" so my panel needs to be replaced. here is the number i called - 1-877-993-7999. Good Luck!

I had the SAME problem, several times, with my NordicTrack A2250 Treadmill.
Allow it to go fully up and then fully down several times, without turning it off. IT seems to "cycle" that way 3 times and then "reboots" itself and starts working normally, again.
I had to figure this out myself... none of the suggestions I read worked.