What Causes Frozen Soda Cans?

[fhamann]

What Causes Frozen Soda Cans?

This problem has occurred to me about 3 times in the past year with 3 different Dixie Narco machines.  The machines are old stacker machines of various types.  The machines work fine for months, then one day someone calls and says that the sodas are frozen.  I find that, usually the diet Cokes and a few other flavors on the bottom of the stack are frozen and have burst open causing a big mess.  The refrigeration coils are not iced over.  I unplug the refrigeration deck while I clean up the mess.  Then I rotate the thermostat control back and forth and I can hear it click.  I set the thermostat to 2, and plug the refrigeration deck back in, and close the machine.  I come back the next day and everything is working normally.  Weeks and months go by and the problem is solved. 

What do you think is going on?  Is this a common problem?  Should I have replaced the thermostat for a more reliable fix?

 

Regards,
Frank Hamann

Orange, CA

[CajunCandy]

Try putting in a new thermostat. It just might cure your problem.

[AngryChris]

The problem is almost always a bad thermostat OR a thermostat that isn't mounted in the right spot.  The thermostat measures the temperature of the air.  If it's right in front of the evaporator, it might be obe temp.  If it's tucked away in a corner, it may be a different temp.  It must go in the right place.  You could also just have the thermostat set too high (it should be 3.5 from "off").  You can't simply eyeball it.  What i do is turn it off, mark where 0/off is, and turn the thermostat 3.5 units.  In addition to that, your thermostat could just be messing up.  It's a pretty easy repair to change the thermostat.

[fhamann]

Thanks Chris for the advice.  Is there a proper mounting place for the thermostat?  I know changing the thermostat is easy, but verifying it is working properly is not since you cannot know for sure if it is working properly right away.  The only way (as far as I know) whether the fix worked is to wait a few days and come back and check.

[AngryChris]

2 hours ago, fhamann said:

Thanks Chris for the advice.  Is there a proper mounting place for the thermostat?  I know changing the thermostat is easy, but verifying it is working properly is not since you cannot know for sure if it is working properly right away.  The only way (as far as I know) whether the fix worked is to wait a few days and come back and check.

Firstly, there is a slit in the fixed part of the evaporator shroud.  If you look straight back from where the knob of the thermostat mounts and look near the back of the machine, you'll see a little slit maybe 1" wide and maybe 1/4" tall.  That's where the tip of the thermostat (usually shaped like a paper clip) goes.

Secondly..
 

 

2 hours ago, fhamann said:

 I know changing the thermostat is easy, but verifying it is working properly is not since you cannot know for sure if it is working properly right away.  

That's not true.  When your cans froze up, that's when you know the thermostat failed.  The thermostat is what tells the compressor to run or stop, and yours kept running until the cans froze up.  It may start working again right after.. but if the same machine has frozen up more than once with the same thermostat, what more evidence do you need to say that the thermostat is malfunctioning?  For whatever reason, it's failing intermittently.  What's cheaper, 4+ cases of soda or 1 thermostat?  What's easier to do, clean out a machine with exploded/frozen soda or change a thermostat?  I don't mess around with thermostats.. and what I mean by that is that I change the thermostat immediately after a machine has frozen up on me.

[AngryChris]

As a note, your deck can freeze up for several reasons, but the ONLY thing that will cause your cans to freeze is because a thermostat did NOT tell the compressor to stop before freezing.  Aside from a short circuit in the thermostat (I am assuming you could short the wires to the thermostat), the only 3 ways to make a thermostat run past freezing is 1) bad thermostat, 2) thermostat that's somehow placed near something warm so that it doesn't sense freezing temperatures (I would say that's wayyyy unlikely), or a thermostat that's set too high (ie. well over 3.5).  It's very easy to set the thermostat on the wrong temperature by looking at the numbers instead of doing it properly -- turning it until it's OFF, marking where OFF is, and going 3.5 units past OFF.  That's the proper way to get to 3.5.  If you got it to say.... 5.. maybe it was already near freezing and it just took the right conditions to make the cans freeze.  The most likely thing is that the thermostat just failed though.

[fhamann]

Thanks Chris.  I will buy a few extra thermostats so I am ready next time this happens.