New USA Labs chiller not dropping below -10c and comprrssor is frosted over

Hello all, i just received my USA Labs -50 chiller and it is filled with 60/40 propylene glycol/distilled water. I let it chill over night and it never dropped below -10c qnd the compressor iced over. Im not sure what could be causing this issue.

Not enough refrigerant could do that. Id consult USA labs though.

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Thank you for the reply, one of my coworkers said he thinks it would be due to low refrigant as well.
I plan on giving them a call tomorrow as well good idea

You should definitely talk to USA Labs - they warranty their stuff.

And also - you have these set in Celcius. The freezing point of Glycol/Water at a 60/40 by volume mixture is -48C and due to it getting “slushy” you should never attempt to use that mixture down to that level.

I should have gotten much colder - but if it had gotten as cold as you wanted you could have caused other issues… like freezing your pump, blowing out your motor, etc.

Also - its possible that beside a refrigerant issue (is the line cold… looks cold if its frosted over…) you could have a temperature indicator issue. Did you test the temperature with something other than the display? If not - you should, just to make sure that its really not getting colder than -10C.

Its possible that the temperature indicator is not working. And if that’s the case you could be much colder. But the system doesn’t know that. So it keeps running longer and longer. And then you got “slushy” and then other things stopped working.

You can tell if its slushy, cause its “thick”. And you can put a thermometer in the reservoir to check temperature.

Let us know what happens and how you fix it!

Hey Pete,

I apologize for the issues that you’re having! Please send an email with photos and the issue to and we’ll get you taken care of first thing in the morning tomorrow.

I really appreciate your patience and hope you have a fantastic night!


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The lines did frost a bit just nothing like our other chiller after 24 hours. If it was a refrigrant issue would it not chill the lines?
My first thought was tempature indicater was wrong it just didnt seem nearly as cold as the other chiller in the shop but i will try getting a read on the resovoir tomorrow.
What mix would you use? I just went off the handbook our other chiller is ethanol so it was easy.
I see the usalabs comment as well and just sent them a detailed email so ill update when we figure it out just figured id ask you about a few of your point to learn a bit more, cheers! Thank you for the detailed reply.

Thank you very much i sent off an email and look forward to the reply!