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Johnson Temp Controller

I am currently using the A19AAT Johnson Temp Controller on a chest freezer. This thing is driving me crazy and I was hoping someone could tell me what I am doing wrong here…It has a set point adjustment screw inside to limit the low cutout temp. I have tried every step of that adjustment and no matter what my temp ends up going from 70 degrees all the way down to the 40’s when I have the temp dial set to 62 degrees…What am I missing here?! Anyone?!

I have two of these at home with the directions. I could look it up tonight when I get home (or do you have the directions?). ... aat-2c.pdf

Yup, have the directions and have followed them as far as I can see…

Ambient temp swings are going to be huge. You want to measure the temperature of liquid, preferably your beer. I put my probe next to the surface of my primary (carboy) and measure the temp of the beer that way. Stays within the 1-2 degree Set Point I have it at and doesn’t cycle very often. Your diF should be at 1 or 2 and ASd should be around 10 to 12. Mine is at 10.

How do I know if I have it set 1-2 or not? I mean, it is just a little screw you slide and tighten onto the steps when you twist the dial…Right now the screw is set slightly to the right of the middle…

Is this the analog one you have? I guess I should’ve known that before replying…

Yes, I believe it is.

Something else to try:
Turn your freezer temp control all the way down. Most default you at around the #4 setting or so I think, turn it down to the first setting (warmest). Anyway, turn it all the way down so it isn’t working so hard initially to get you to the set temp of your controller. It may run a little bit longer to get you to the set temp but hopefully wont over shoot so far.
This helped me out quite a bit.

Alright, I am going to give that a try.

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