Frost build up especially on top shelf all other shelves except one gets a 3 inch layer of ice in approx 4 months. The freezer is kept in a mod temp basement room and the freezer door is opened less than once a day. The freezer has been like this since we bought it 4 years ago.

just to be sure that your door is sealing properly, put a flashlight into the freezer and turn off all of the lights in the room to see if there are any openings in the seal. Iam suggesting you this coz sometimes a small opening may pass our eyes easily....

if the door is sealing properly......
If this is the type of freezer where the shelves are the evaporator coils, the coolant goes through the shelves(tubing) and the formation of frost is normal and has to be manually defrosted.All the shelves should be as cold asd the top one. The fact that just one has any frost may indicate that it is low on freon. If this is the case you should notice that the freezer doesn't get cold enought just like you said... so check your freon levels.

This could also be because of the thermostat not sensing when the fridge reaches its set temperature and as a result of this the compressor will keep on running and build-up of ice will occur.

Follow the advices in the order prescribed above and you should be set

Hi,

On this unit the shelves are the cooling coils and carry the refrigerant (freon) through the system. They will attract the warm moist air by design, so if you have an air leak in the door or elsewhere it will tend to build up there first.

This being said you need to check something else first. Make sure the other shelves are cold. If they are frosted and cold like normal then you most likely have a door that is not closing all the way or a bad seal. If the lower shelves are not cold then you have a system problem, typically a refrigerant (freon) leak that is causing the top shelf to absorb most of the work and not enough refrigerant to flow to the bottom shelves.

I hope this helps

it may be that the door is open a lot witch lets in warm air that go's to the top of your freezer and turns into ice so there maybe nothing wrong with your freezer, in winter we heat the house up and close all the windows this holds in the damp air,, in the summer it should be ok, but to test it place a thermometer in the freezer is should be about -21*f or there abouts for a 4 star freezer

If is the type of freezer where the shelves are also the evaporator(shelves are very cold and is normal to frost), the fact that only one shelf is iced would indicate the system is low on freon due to a leak. This would also explain the hot walls and compressor. It requires a service man to check the freon level and locate leak and recharge.

If this is the type of freezer where the shelves are the evaporator coils, the coolant goes through the shelves(tubing) and the formation of frost is normal and has to be manually defrosted.All the shelves should be as cold asd the top one. The fact that just one has any frost may indicate that it is low on freon. If this is the case you should notice that the freezer doesn't get cold enought.

have you checked the door seals on the freezer. sounds like its getting air into the compartment and causing the problem.

This link might help you troubleshoot
Freezer Frost inside Symptom Diagnosis Sears PartsDirect
The lucky solution is if the door seal or inner plastic liner need to be placed/repaired (this lets warmer air into the freezer causing frost and poor cooling).
But you can also see from the link that your symptoms could be caused by other electronic related things...more of a challenge to fix...
Helpful?
Good luck on your troubleshooting

That is normal. The refrigerant runs through those shelves. They are the evaporator side of the unit.That is where the freezing effect comes from.
Check door seals for leaking air.
Keep door openings to a minimum.
Get in there and get out.
Those things will help prolong frost/ice buildup.

Your freezer is low of freon.

The model number would help but it sounds like a sealed system leak or restriction. If thats the case I would not suggest trying this yourself. The water should freeze overnight and the frost should keep going to all the shelfs that have coils in them.