Dixie Narco 501E Freezing Up

[rjh914]

I've got a DN 501E freezing up on the evaporator.

I melted all the ice away on Thursday, then plugged the machine back in.  Friday morning it was icing up again.

I slowly turned the thermostat counterclockwise to kick it into defrost cycle.  I let it run like that for about 45 minutes and the ice cleared from the evaporator.

Is this symptomatic of a low Freon charge or bad thermostat?

Thanks.

[Magiccity726]

Most likely need a new thermostat 

[AZVendor]

If you have no water standing in your cabinet and no large air leaks such as a bad door gasket, missing or stuck delivery port door or a t-handle that won't close the door snug, then it is probably low freon.  Any of those issues must be fixed to prevent icing.  It doesn't need a thermostat if the compressor cycles normally when it has no ice, though it might not if you have low freon.  If your ice grows from the top right corner of the evaporator then moves across the evaporator to the left then you have low freon.  If the ice forms on the whole evaporator at the same time then you probably have a bad evaporator fan motor.  This all assumes you have good valves in the compressor.  Bad valves usually show ice on the accumulator first.

[AngryChris]

I recently had an evaporator freeze over.  I changed the evaporator fan motor and all is well again.  In addition to that, however, i had to remove the drain hose, clean it out, and clean the little part too as it was all full of corroded gunk.  The fan motor shaft had a lot of movement in and out.  Apparently that's a way to confirm that the motor is worn out.