Need an "O" ring Jura Capresso C1000

Hi, a video how to fix your Jura step by step, good luck... http://fixandparts.wix.com/nicknicoloudis#!jura-coffee-machine/c15gy

thermal sensor error

No, first push the self clean button (hold until lights come on). Then pull the grounds unit and empty it, that will turn off one red light. Fill the water tank. Then drop the tablet. Then hit the ground coffee button. Cycle through and dump the grounds each time the grounds light illuminates.

turn knob to steam, press the water dropplets button then change back knob,

It is not a recommendation but in an emergency you can us a 1/4 teaspoon of bicarb

Quite possibly, you can find what you're looking for at an aquarium supply store. They have different types & sizes of tubing.

Machine is not getting water.

call capresso, they will go through the whole machine for a small fee, or offer you a new model at a reduced cost

What part do you need?

Do you descale (de-calcify) your machine on a regular basis? If not you need to try that. Jura has a big square tablet for that and there is also a liquid product called Durgol.