Frigidaire upright frostfree freezer keeps icing up, needing to be defrosted. whats wrong with it?

the sides is were the condenser is it is called a hot wall condenser try to keep things from the sides so it can run more efficeiant

Clean the unit entirely, coils, filter, etc. Then retry. You might have a faulty control board since it has not been used in many years. All depends on the location and humidity. That can tear up a thermostat and control board.

Sounds like one or more of your defrost components are bad. Those components are defrost heater, defrost thermostat, and defrost timer or board depending on model.

Sounds like frost bulidup from door being left open warm air gets in making frost and ice. Need to turn off for 24hrs or so to let all the ice melt compleatey then turn back on keep door closed run for 24hrs check Temp. shoud be about 0 to -5 Deg. if good start using.

The defrost drain is most likely frozen or clogged. I put together some instructions on clearing this for refrigerator/freezers and it applies the same to all freezers with drains. Take a look and let me know if you have questions.

http://www.fixya.com/support/r4686046-water_leak_from_freezer_ice_freezer

It's not dangerous ,you jusi have to defrosted manually by unplugged and let it defrost about once a week.

pour some hot water in the drain if this does not work use compressed air

This happens when your thermistor gets frozen along with the coils or there is a clogging of the freezer drain which causes Ice to build up and spread to the system. Another issue is that your thermistor may be faulty, telling the system inaccurate temperature. Incorrect freon pressure can also be a cause. I would advise first to have the ice melted by letting the unit stay unplugged and have it cleaned while at it.

more info would help but sounds like you have a defrost problem and need a technician

It sound like you had a freon leak, you REALLY need to get this checked by a tech. if you are leaking freon it can be dangerous.