overheat: left it on all night and now doesn't work
Check heating elements
check overtemp switch
heat light coming on?
to be sure: bypass switch (connect wires from overtemp switch together and run for a few minutes).
Heat Light comes on? Chamber get warm?
If yes, replace switch
If no: check function switches
To reset switch: Turn counter clockwise, run unit, when temp reaches 262 degrees,
turn switch clockwise until light goes off (contacts break) allow to cool (double check this with mark at rpi)