I have a Bosch double oven Model # HBL556AUC. The top oven doesn't work. I have determined (I think) that I need a new thermostat. Here is the problem. When I looked in my oven and on the diagram that Bosch has on their website, it shows a thermostat bulb or tube which is single and thick. When I purchased the part that Bosch told me to purchase, it had 2 tubes attached to it and they were thin. The part # is 490990. Bosch told me that this is the correct part,however they would not tell me if and why they switched to a 2 bulb system. I stumbled on your website and found that the picture that you have has 2 bulbs for the upper oven. (unlike the picture that Bosch has on their diagram.) Please help. I'm confused and I want to know if this is the correct part and how do I install it. (It is a different size part).

Thank you.

Danny