We purchased this Mccall commercial refer used at an auction about 6 months ago, placed it in our garage and are using it to store perishable items for our farmers market events. It has been working great untill now, the temperature outside in the PNW has dropped into the low low 20's (not so normal) for a few days now and my wife noticed the refigerator was blowing warm air inside. I investigated the unit with my novice knowledge, I have a hunch the ambient temperature is a player in this. The evaporater was not iced up at all and turning the thermostat to the coldest setting did not kick in the compressor. Just to make sure the compressor was in working order I bypassed the thermostat and plugged her in and the compressor came on so I let it run for a while and sure enough the cooling cycle was working fine and refer box got cold.

So my question is: is the ambient temperature the culprit affecting the thermostat or could it be a bad thermostat.

I know this is a commercial unit and hope it's not beyond this forum, any help would be appreciated.

Thanks for the quick response Denman,

I have been very much educated today on the drawbacks of having a refer or freezer in the garage. Though this does not pose a threat for us in the summer months as our garage stays fairly temperate I did locate a manual that covers this unit if that helps you to help me:
http://www.basequipment.com/v/s...ccall/44045G-SERVICE.pdf

I also came across this product: a "Self-Regulating Crankcase Heater" while googling for info, Its used to keep the compessor warm durring those cold spells protecting the oils with in.
http://www.tycothermal.com/assets/Americas/English/Document/Installation%20Operation%20and%20Maintenance%20Manuals/2619/H55593_FreezGard_II_0109.pdf

So the question that still remains for me is how do I trick the thermostat (if it is indeed good) to cooperate.