Yes, the tube is fed in from behind or above. Some thermostat bodies have a small adjusting screw to allow you to calibrate if it is fairly close. The videos show it is a simple job.
The issue you're experiencing with your Bosch convection microwave not heating in convection mode could be caused by a few different things. Here are a few things to check:
Check the settings: Make sure that the microwave is set to convection mode and that the temperature and time settings are correct.
Check the element: The bottom heating element is responsible for providing heat during convection mode. Make sure that the element is not damaged or burnt out. You can visually inspect it, if it is damaged it will need to be replaced.
Check the fan: The fan is responsible for circulating hot air during convection mode. Make sure that the fan is not blocked or damaged. If it is, it will need to be replaced.
Check the control board: The control board is responsible for controlling the functions of the microwave. A malfunctioning control board could prevent the microwave from heating in convection mode.
Check for a blown thermal fuse: A thermal fuse is a safety device that cuts off power to the oven if it overheats. If the thermal fuse is blown, it will need to be replaced.
Check for a blown thermal cut-off: A thermal cut-off is a device that cuts off power to the oven if it overheats. If the thermal cut-off is blown, it will need to be replaced.
First of all, oven doors are not designed to be disassembled for cleaning of the sealed glass panel. That being said, you may be able to use a coat hanger to pry the hinges open against heavy spring pressure to allow reassembly.
E-126 ERROR CODE ... received this morning due to some burned toast! After smoke cleared and the oven cooled down I continued to display the error. I decided to let it sit for a few hours and after reading that it would need to be reset by a technician ---- I cut all power to the oven and then back on. The oven reset itself allowing me to reset the time. All functions appear to be back as expected, so this could be an option to try if you receive this E-126 flashing error code saving a service call! Hope you are lucky!