How I fixed Z banding on my 12" i3v. AL Y bed and solid state heat bed relay/PID

[tsteever]

You can turn on the Thermal Runaway protection in Marlin.

[printbus]

You can turn on the Thermal Runaway protection in Marlin.

Not really. Thermal runaway protection still depends on the heater control circuit working properly.

EDIT: I should qualify this. IIRC, if the printer is wired so that the printer power supply can be controlled by gcode commands, the thermal runaway protection will shut the printer off and turn off the heater. Otherwise, a stuck heater circuit is a stuck heater circuit and the heater will stay on. BTW, both mechanical relays and MOSFET-type solid state relays tend to fail in the "ON" state. Mechanical due to contact arcing and MOSFET because of the substrate nature of the device.