How to use a Ranco 2-stage Temp Controller

OK  The instructions seem easy enough.  I’m using a Ranco 2-Stage Temp Controller on a commercial 2-door lab fridge, which I’m trying to use as a fermenter.  The thing just stares at me.  I’m trying to cool to 65F and the ambient temp is 77F.  Everything seems plugged in the right way.  The fridge works.  Any suggestions.

Hmmm wish I was there to see it. Are you sure you have fridge plugged into the correct stage?

Yep, fridge is plugged into the S1 outlet and set up as C1 for cooling.

I wonder if they got the labels wrong. Maybe try swapping them.

What do you have the differential set at?
Does the temperature display show 77  or is that from another thermometer?
Do you have the heat stage set at a temperature well below the cooling stage so that you dont have a conflict?

Tried switching

The 77F is in the display.  I assume it’s the ambient temp.  I have the temp probe inside the fridge, in an empty White Labs tube that’s filled with water.  I have the cooling set for 65F with a 3 degree differential, and the heating is set for 55F with a 3 degree differential.  There shouldn’t be any overlap.

It’s either programmed wrong, broken, or the fridge is broken.

Plug a lamp into it. Good bulb and turned on. See if it turns the bulb on when it should be turning the fridge on

I don’t think you want the probe wet.

I set mine with both heat and cool at 65 with 2° diff. If it’s warm out I just unplug my heat source

I tried taking the probe out of the water.  The fridge starts right up when it’s plugged in directly.  Even though I didn’t get it from MoreBeer (got it online from ETC), some reviewers on MoreBeer said their units had a software issue and customer service (which is closed until Monday) was able to resolve it.

Hopefully that solves it. This kind of stuff drives me up the wall. I hate when I get something home and it doesn’t work.

Appreciated your ideas, though.

:smiley:

Have you tried heating the probe a lot to see if that kicks it on?  Hot water for example?  You could try it in ice water too, see if that does anything.

At this point, I am grasping at straws.  I think I’ll have to return it for another one.

It seems like you have everything set up just right. I too bought mine directly from ETC. They had good customer service (last year), so hopefully they can help.

BTW - The probes are waterproof. I either have my probes in water or taped to the carboy.

Cool. I have mine taped to the interior wall.

Sorry Amanda, the probes MAY be water resistant, but I can say from experience that the are not waterproof (immersible).

Yeah - they probably could hold up in water, but most vendors (my LHBS included) says to not count on it.

The single-stange Johnson probe is all stainless, and it definitely is waterproof.

As far as the Ranco - they are pretty solid machines.

Maybe you have the heating/cooling functions set incorrectly? Or maybe the you’ve set the offset to your temp setpoint instead of the actual temp setting.