I have a whirlpool 21' no-frost desginerstyle bottom freezer refrigerator with frost and ice build up in the freezer. I have defrosted and removed ice behind the back panel in the freezer several times only to have it build up over weeks and the frig turns warmer and the freezer gets colder. then frost builds and blocks the airway into the frig from the freezer. What needs to be repaired? fan is functional.

is it a frost free model? if it is the defrost timer may be out or the defrost element may be bad. but if this is not a frost free model the door seals may be bad and need replaced

you now have a defrost issue,remove rear panel inside freezer if the evaporator is covered with a heavy ice and frost build-up then either the defrost heater under the evaporator coil is open or the defrost thermostat on top of the coil is bad you need to check both for continuity or the defrost timer if equipped or the A.D.C. adaptive defrost control is bad and not supplying power to the defrost circuit

either a leaky door seal blocked drain in the freezer or burnt out defrost heater element

The refrigerator is supposed to self-defrost approximately four times in every 24 hour period. If one of the components in the self-defrosting system fails, the refrigerator continues to try to cool. Eventually, though, so much frost builds up on the evaporator coils that the circulating fan can't draw air over the coils. There may still be a small amount of cooling because the coils are icy, but with no air flow over the coils, cooling in the refrigerator compartment is quite limited. Here's an inexpensive, though inconvenient, way to determine if the problem is with the self-defrosting system. Remove all of the perishable food from the refrigerator and freezer, turn the thermostat in the refrigerator to Off, and leave the doors open for 24 to 48 hours. (Be sure to have several towels ready in case the melting frost and ice causes the drip pan to overflow). This allows the refrigerator to defrost "manually." When the frost and ice build-up has completely melted away, turn the thermostat back to a normal setting. If the refrigerator then cools properly, it indicates a problem with one of three components in the self-defrosting system: Poor cooling is often the result of a heavy frost build-up on the evaporator coils. You can't see these coils without removing a panel on the inside of your freezer. A sure sign that there is a build-up is the presence of any frost or ice build-up on the inside walls, floor, or ceiling of the freezer. Such a frost build-up usually indicates a problem in the self-defrosting system or damaged door gaskets. The defrost timer The defrost thermostat (also called the bi-metal switch)

This can be caused by the drain hole below freezer coil being blocked by ice. You MUST remove all ice in drain under freezer coil. Use turkey baster to squirt hot water into hole and use hairdryer to defrost. Possible defrost thermostat is defective. Unit never goes into defrost, ice forms on coil and in floor of freezer. After defrosting may work OK for a week or two but gradually gets warmer because ice is blocking ports where cool air gets to refrig. May also have water in refrig box. Can also be caused by defective defrost timer.

If freezer is icing up, you might have a defrost problem. Frost free models have a heating element that is controlled by a timer to automatically defrost ice, ie defrost timer turns on defrost heating element every 12 hours to melt ice in freezer and allow good air flow.
You can test defrost element with an ohm meter(located inside freezer coils-will have two wires going to a plug connection), if OK replace defrost timer (located in various places depending on make and model

too defrost just open the doors for a day with the unit unplugged. as far as why it is frosting up check door seals make sure they are all good and seal it up well and that should take care of it.

You should to check the Whirlpool Gladiator Freezerator's door sealer to make sure all rubber or plastic seal very well to prevent air humidity come in to build up frost fast. Also, you have to defrost completely and wipe with cloth or paper towel to absorb all waters out and let it dry completely to prevent frost build up.

is it frost or ice.if frost you will need an ohm meter to check continouty on the heaters and term thermostat.term thermo must be cold to check.if ther ok check voltage to the heater system from the defrost timer.if no voltage replace timer.if its ice it could be a blocked defrost drain.unblock clean out

your sure the defrost cycle works? sounds to me its not. you need to remove the freezer back and check the defrost components. or put it in the defrost cycle and see if it is working. to get that much frost as you describe the dor would have to be left open. also check all door seals. let me know what you find and we can go from there