Troubleshooting Fermentation Freezer

[hillhousesawdustco]

I purchased a Frigidaire FFU21F5HW upright freezer to use with my plastic conical for temp control. I'm using a dual-stage temp controller off amazon with a small heater inside the freezer.

Worked great for two months. Now it isn't cooling. It has the front indicator display that is supposed to show 1 to 7 to indicate the level of cooling inside. Now that display is just a mixup of random symbols when I press up or down.

When I plug in the freezer (to either a regular circuit or the temp-controlled outlet), the hi-temp and door-ajar lights come on and there is a beep, but then the lights go off and nothing happens. I believe when I very first noticed the problem that the indicator was displaying a "P" rather than the "1" it should have been on.

I have the temp controller set to allow five minutes between switching the compressor so that it doesn't come on for 3 seconds all the time. Obviously the compressor isn't working at all now...think it's fried??

Frigidaire says it is under warranty and they'll pay if I get somebody local to look at it....the problem being that it is in my brew shed and I cut off the door shelves to get my conical to fit....so I assume that would void my warranty.

Any help would be much appreciated....darn thing is only two months old. My keezer functions in the same fashion (although admittedly single stage) and has been running for a couple years.

 

[hillhousesawdustco]

No freezer techs on HBT? Durn.

 

[day_trippr]

Not a freezer tech, but had to comment anyway.

If the display is that out of whack it's likely the system doesn't have enough function to control the compressor. My bet is the $59 controller needs replacement and everything will come back to life just fine.

As for who pays: if the unit is under warranty, it seems to me the problem should be diagnosed to its root cause first. Then see if the Frigidaire folks try to blame a defective controller on some mods to the plastic freezer guts.

I s'pose you could replace all the shelves first, then call. I bet just buying a new controller and installing it yourself would be cheaper

Cheers!

 

[hillhousesawdustco]

Thanks very much for the suggestion, might just give it a shot! I'll check the wiring diagram and see how much a pain it would be to "jump" the compressor wiring and see if it'll run.

 

[uncommonsense]

My dad (who is an hvac tech) say that some freezers are not ment to run at temps much above freezing temps. The compresser can't handle it and they burn up. I see lots of people have good luck with chest freezer but I wonder if the up rights can't do it.

 

[hillhousesawdustco]

Well I purchased this particular model because it is oft-recommended on this forum and indeed by Blichmann for their fermenter/brite tank models. I don't think vertical vs horizontal would make any difference in the freezer wearing out with limited use (2 batches) over two months but I could be mistaken. From what I understand one of the issues in uprights can be temperature gradiants as the cold sinks to the floor, kicking in the heater, and causing cycling issues but I thought I'd addressed that with the 5 minute delay between switching from heat to cold.

 

[ackbrew]

I was debating building dual stage or simply buying single stage. I ended up buying a single stage controller, and trying various heating methods, while using the controller to cool. First tried a ceramic heater, but the temp swings and cycling were too much. Then I tried various wattage light bulbs to see what maintained my desired temp, with minimal cycling of the freezer. I never saw the point of dual stage.....

 

[ChuckO]

Quite often freezers with digital microprocessor controls will not function properly with an external control switching the main power on and off. They need to have power supplied to the controls all of the time.

 

[hillhousesawdustco]

It worked dandy for those two batches- maintained perfect temps and crash cooled like a champ. This one always fired right back up on the settings that I had left it on whenever the controller turned it on. I've tried running it straight off a non-controlled circuit with no luck (ie, just running it as a freezer).
The idea of the dual stage was just for ease-of-use. I could start fermentation low (around 62 for the two beers I made) and ramp it up slowly to 68. After 20 days it was easy to crash it to 34 degrees for a few days. I was trying to make a relatively professional temp control work without a jacketed fermentor, glycol, etc. This temp controlled conical thing is sure cool but man is it currently a pain in the butt!