Hi, so my parents treadmill stopped working and I found that it had a blown mosfet so I replaced it with an identical mosfet which got the treadmill back up and running, however after a few minutes the mosfet blew again. I think this might be from inductive kickback from the DC motor that runs the treadmill because I have not been able to find anything shorted on the board besides the newly destroyed mosfet.

So anyway I want to add a protection diode in parallel with the motor and I'm not sure which one to use, does anyone know the math for what kind of diode I will need in relation to the size of the motor? Can I use a regular diode or should it be a shottky diode?

Thanks