Chest Freezer Temp Control issues

Bought a chest freezer to replace the fermentation chamber I had built. I am having trouble keeping the temp at a nice steady temp. I have the temp set to 19 C with a .5 degree difference. The freezer kicks on at 19.5 and sends it all the way down 18 if no heater is turned on. If the heater is turned on, it clicks on at 18.5 and sends it all the way to 20.5. Then of course the freezer turns on and we start the process all over, with a never ending back and forth. Now I wall say the heater I am using is probably too big but I am not sure what else to use. Any suggestions? I have heard of using light bulbs or like utility light.

I’m guessing you’re using an STC-1000 with the temp probe in air. You can change the difference setting to as little as .3C.

I think you should put the probe in a glass of water. If you find the freezer cycling too often, use more water.

Probably lose the heater, unless the ambient is cooler than the freezer.

callisbeers said:

[...]Now I wall say the heater I am using is probably too big but I am not sure what else to use. Any suggestions? I have heard of using light bulbs or like utility light.

Click to expand...

So tell us, what is the BTU rating of the heater? I laugh when I read of people using 200w heaters or even 1000W hair driers in fermentation chambers. Crazy stuff! Meanwhile, fwiw, I use a 40w bulb as the "heater" in my 17cf ferm fridge, and a 100w resistor ceramic resistor array in my 32cf modestly insulated ferm chambed (no chiller, it's for cold season brewing only).

And where do you have the temperature probe located? Hanging in air, dunked in water, or strapped to the side of a fermenter and insulated? (<= imo, that last one is the best way to go).

Btw, very few if any consumer-grade wired temperature probes are waterproof from the factory...

Cheers!

The air temperature will swing a few degrees, five gallons of beer will not fluctuate temp much if at all.