It has been a few years but I thought that thermistor topped out at 199 degrees (2500 ohms rings a bell).
Is that the model that routes the thermistor wires thru a conduit at the back of the control panel on top into a splice box about knee-high before it connects to the thermistor? When I worked for Hobart, I had one that had an intermittent connection in that splice box. It drove me nuts trying to figure out why it worked just fine when I was there, but it would not indicate the next day.
Hope my ramblings help you,
Sorry that I could not help you.
I don't know if Hobart will give you that value unless you agree to buying a brand new thermistor.
Is there another C44AW in your customer base that you can check the value against? It has been almost 5 years ago that I left Hobart, but I thought that thermistor was the same on the AM-14 as well as the Conveyor dishwashers.