My kenmore elite commercial freezer has all of a sudden stopped getting cold and is now blowing hot air. Does anyone know what I should be checking?
When your refrigerator has working lights, the inner fan (or blower) inside the fridge is still blowing and the air is room temperature, then possibly the problem is the Compressor Start Relay. The start relay is a small device mounted to the side of the compressor. It provides power to the winding for a split second at start up to help the compressor run. The other component that may have failed could be the Start Capacitor. The start capacitor acts almost like a battery to give the compressor a small boost during power up.
Dean is a spambot, so don’t pay any attention to what he says.
I’d check your compressor. It sounds like you either have a bad compressor or a bad start relay on the compressor.
This is the start relay.
Frigidaire 297051000 Controller - AppliancePartsPros.com
Its on the side of the compressor and it pushes onto three terminals that stick out of the side of the compressor.
I’d disconnect the refrig. from power and pull the relay off. If you shake it and it rattles or little pieces fall out of it, its shot.
Order a new one and try it.
If you had a hermetic system analyzer handy you could check the compressor, but they are sometimes hard to come up with. 
