I'm sure I'm missing something obvious but shouldn't currentFreezerTemp on line six be 17.26 not 2.2?
Hit Run Actions and then refresh the page. What is displayed depends on when these things happened.
Are these Hub Variables or Local Variables?
Turn on Action Logging, and post the logs of the rule running.
One other thing to bear in mind, what is displayed in the rule are final values, not progressive or interim values. Both the value of currentFreezerTemp and freezerTempDelta are set more than once in the rule, so what is displayed is where they end up at the end, not where they were at any given step -- which is what you seem to be expecting. You can add Log statements to show the progression as the rule actually runs.
I would like to see the values as they progress.
As it is, having figured out how the values are displayed, have no problem with the way they are displayed.
Webcore from the ST days, worked well in this issue.
When you are looking at a rule as it is setup, it is not executing. The rule runs driven by events, and when triggered it runs for a fraction of a second. So just what do you think it means to see values as they progress? If you want to see those values as the rule runs, you would need to put in Log actions to display the values in the logs.
Incidentally, this is a universal problem with software. Computers are fast! You don't get a chance to watch them in action, you can only see the results of the computation. So, debugging code often entails adding mechanism to take a peek at what is going on, but even this is going to be after the fact looking back at what is already done. Sometimes, code simulators or testbeds are created that allow one to step through software very slowly. This is no panacea however, when millions of instructions have to run to get to the end.
Debugging a rule like the one in the OP above is best done by just walking through it with a piece of paper, tracking through the logic. If you find yourself stumped, put in a Log action. Then you can have your V8 moment of seeing what you missed in your logic.
I missed line 7