How does a defrost thermostat work?

[pvburton]

Over a year ago, I turned my old side-by-side fridge into a fridge-fermentor with two STC-1000s. After much (probably too much) reading into it, I decided to disable the defrost timer as I was worried about things getting too hot during the defrost cycle because I totally bypassed the factory temperature controls.

Now, of course, 2-3 times a year during the warmer months, I am left with compressor coils covered in ice and I have no choice but to turn it off and leave the door open for several hours to let it thaw so that it starts working efficiently again.

After a bit more reading, I don't think there's any harm in hooking the defrost timer back up, however, I am not sure it will do any good either as I run the freezer at 42F.

Can anybody provide a good explanation of what the number ratings on a defrost thermostat actually mean? I have yet to find a succinct explanation of what happens at what temperatures.

 

[JONNYROTTEN]

I've taken a screwdriver and hammer chipping blocks off my coils on my 80's commercial fridge when I've run it for months unwilling to unplug my fridge to let it defrost....I unplug when empty which isn't every often...Following for a better solution

 

[cas3439]

I believe most of the defrost timers turn on after a specific amount of compressor run time. I've built 2 side by side kegerators and left both defrost timers intact and never had to manually defrost once since I built the 1st in 2011. The only thing you really have to worry about is hooking up your fridge side fans to not be running during the defrost cycle. you say you keep your freezer side @ 42F, but obviously its enough to build up ice on the coils. Trust me you'll never pull a beer and say, "Wow this beer is warm, the defrost cycle must be running." Put the defrost timer back in the circuit and save yourself some trouble and headaches.

 

[pvburton]

Thanks for the feedback. I just ordered a replacement defrost timer; got done primary fermentation in the fridge side (maiden voyage of actually fermenting in this thing) and its all iced up again after only 2 weeks!

Why should I keep the fridge side fans off during defrost?

 

[cas3439]

Thanks for the feedback. I just ordered a replacement defrost timer; got done primary fermentation in the fridge side (maiden voyage of actually fermenting in this thing) and its all iced up again after only 2 weeks!

Why should I keep the fridge side fans off during defrost?

Because when in defrost mode, you more than likely don't want to be pulling any warm air into the fridge side.