How do I fix a loose selector knob?

No answers for this issue , but we have the same problem

http://www.fixya.com/support/t26840034-knob_our_breville_cafe_roma_become_very https://www.centredurasoir.com/media/products-files/ESP8SXL_User_Guide.pdf

If the buttonhole dial has been rotated so that its indicator mark is not at zero (vertical aligned with the plate indicator mark), the stitch width dial will not function. Turn the buttonhole dial clockwise to the vertical mark.
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contact the bosch service agent for spares

You will need to take the machine in for service.

Hi cfipp
You could fix this problem with a quick squirt of CRC 2-26 into the function selector switch connected to the knob you are wriggling. This will sort out the problem. If you need further advice, feel free to ask me. I will help you. 
regards robotek

First, feel the heater hoses going into the firewall under the hood. If they are hot, then you have hot engine coolant going into the heater core. If they are not hot, then you either have a bad thermostat or you are very low on engine coolant.

Next you need air flowing through the heater core so it can come out heated through your vents. If the iar is flowing somewhere else, your temp blend door is not moving because the bend door motor is bad or your temp knob on your heater controls is bad. The blend door motor is an electric motor.

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Air Flow Control
Air flow control is accomplished in the following manner:

• Primary control is through the function selector knob , mounted on the heater function selector switch, which is part of the heater control .
• The function selector knob has the following positions: OFF, PANEL, PANEL/FLOOR, FLOOR, FLOOR/DEFROST and DEFROST.
• The heater function selector switch combines a vacuum selector valve with an internal electrical switch.

• The vacuum selector valve directs source vacuum to various vacuum control motors (18A318) . Refer to the System Airflow Schematic and Vacuum Control Charts.
• An internal single-pole electrical switch is also controlled by the selector. The switch controls the electrical supply to the heater blower motor switch (18578) .
• The position of the function selector knob determines the manner in which the system will operate.
• Each position of the function selector knob is detented for positive engagement.

Temperature Control
The temperature control operates in the following manner:

• Temperature control of the heater system is determined by the position of the temperature control knob (between COOL-BLUE and WARM-RED) of the heater control .
• This control knob is connected to a potentiometer mounted in the heater control . This potentiometer is electrically connected to the electric blend door actuator that operates the A/C air temperature control door.

• Movement of the control knob from COOL (Blue) to WARM (Red) causes a corresponding movement on the air temperature control door and determines the temperature that the system will maintain.

System uses a reheat method to provide conditioned air to the passenger compartment.

• All airflow from the blower motor (18527) passes through the A/C evaporator housing .
• Temperature is then regulated by reheating a portion of the air and blending it with the remaining cool air to the desired temperature.
• Temperature blending is varied by the air temperature control door, which regulates the amount of air that flows through and/or around the heater core (18476) , where it is then mixed and distributed.

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inside you plenum box:

turn knob to solid dot then leave it for a little while to reset then turn it onto the desired cycle

If the problem lies with the contacts, then the knob is not the direct problem, it would be the selector switch behind the knob. Although I don't understand how leaning on the to makes the machine work. Are you sure it is not the switch that indicates when the lid is closed? Either way, Yes!! you can simply just change the switch over.