Whirlpool French Door Style freezer not cooling

[Finley3891]

Model Number: MBF2258XEW4
Brand: Whirlpool
Age: 1-5 years

Hoping to get some help here...We have a 5 year old Whirlpool French door style bottom freezer refrigerator that the fridge is cold but not cold enough and the freezer is not cooling at all. The fridge runs constantly. Any help would be greatly appreciated!

[denman]

Please note that all cooling comes from the evaporator in the freezer so I cannot explain why the fresh food section is cool while the freezer has no cooling.

Check that the evaporator (freezer) fan is running.
If not then that may be your problem.
Check the voltage across the fan.
If you have 120 volts, then replace the fan.

If the fan is OK.
Remove the evaporator cover in the freezer so you can see the coils.
Do not let them de-ice.

If they are heavily iced/frosted over then you have a defrost problem.
Manually force a defrost cycle, see the tech sheet. When the fans and compressor turn off, you are in defrost.

Now check the defrost heater to see if it is on.
Be careful you do not want to burn your fingers.
If the heater is on then the defrost board needs replacing.

If not on.
Unplug the unit.
Remove the wire for one side of the heating element from the wiring and measure it for continuity, usually around 20 ohms or so.

If the heater is OK
Remove one wire to the defrost thermostat (clipped onto the evaporator coils) and measure it, should be 0 ohms when frozen. Note that it opens just above freezing so must be frozen to check it. Also inspect it, if it is bulged at all replace it even if it measures OK.

If both the above are OK then odds are the defrost board is toast.

If you only have frost in one area (usually where the freon enters the coils) or no frost then you probably have a sealed system problem.
This will be an expensive repair as you need a pro, often it makes more sense to put the dollars towards a new unit.
Be sure that the compressor has run for a couple hours because if you do this shortly after/during a defrost cycle yo could come to the wrong conclusion.