SMC Discussion Areas

I resurrected a Cav 72 about four years ago, including having the compressor replaced. It's been working fine, but recently, the front of the evap and the lines near it, are getting really iced up. Is this a problem? What is the most likely problem, and why does it seem to be recent problem?

      Check to see if the fan behind the coils is spinning fast.

The fan seems to be running fine. It was hard to see, because I couldn't see through the ice. I removed the tennis-ball-sized round plate in the center, and then could verify the fan is running well. By then, the ice was melting - even though the machine was still running. So, I let it melt before I closed it up. BUT - I also found that the lines from the compressor, UNDER the cold box, were also heavily iced. What's going on here?

       The thermostat may not be shutting the compressor off when desired temperature is reached. It's easy to replace.

If the thermostat were the problem, wouldn't the product be freezing? Should I just try adjusting the thermostat to a warmer position?

Most of my machines cool great with the t-stat set to 3

Icing is usually lack of airflow (dirty coil, fan not working) or low charge of refrigerant.  Any oil leaks detected?

I don't have a tester. But, how long could it leak, and still stay cold?

I'm having the same issue with my USS-8-64.  Did you find out the source of the icing up?  I've tried adjusting the T-stat but no luck...

Nope, not yet. I tried adjusting the "coarse" T-stat adjustment warmer. It's still 34 sometimes, in the box. That may be the trouble. I need to get it warmer, yet, I guess.

You can always take your t-stat out and put the tip in a cup of ice water.  When you slowly turn the dial, you should hear a "click" which would represent the setting that would correspond to around 32 degrees.