bjarne:
It is not the sketch side itself that I had problem with, but rather (I think) the number of string that I used, which would used up variable space with being shown as global variables. For a test try to make your strings a shorter, or even get rid of some of them. I used to make changes in places totally unrelated to where my problem showed, and it went away.Do you have a URL or part number for the sensor or switch you have in the pan.
You might not need a ground wire, but since you already have a 10k series resistor, the readings should have been cut in about half, did they? I am assuming they 10k resistor is in addition to the one you added for the test.
there is no sensor in the pan, it's just the wires... open... with enough water it will close the circuit.
as far as the 10k resistor... see my drawing of the circuit... maybe i misunderstood... but i put the 10k between the return-wire and the A0 pin... ground pin was never touched.
or do i need two resistors ?
one as shown above, and another to ground (red)?
or is it just the one to ground (red) ?