My GE Monogram ZISS480DMSS Freezer temperature is too warm. It is not reaching the temperature it is set, which is 0 degrees. It stays between 15-20 degrees.

There is a balance between the freezer and fridge. Reduce the freezer temp and see what the fridge temp does. By reduce I
mean make the freezer warmer. If it is set too cold the fridge gets colder.

make sure back and bottom of outside unit are clean coils, fan, if so then your defrost switch has gone haywire

Generic instructions to set temperatures in fridges:

Many manufacturers design these appliances to operate at 0 degrees F in the freezer and 34 to 36 degrees F in the fresh food compartment.

To set the temperature correctly, fill a glass with water (8 to 12 ounces) and place a thermometer capable of indicating 32 degrees and up into the glass with water (if the temperature goes below 32 degrees, the water will freeze - so no need to find a thermometer that indicates any lower). Place the glass with the thermometer in it on a shelf and wait. Putting the thermometer in a glass of water helps preserve the temperature reading while the door is open. You can skip the water and glass if you want - but you'll need to read the temperature as soon as you open the door.

The freezer will require a thermometer capable of displaying 0 degrees F. Place it on a shelf where it can be seen readily - but preferably in the rear - between items (to prevent the warm air from driving the indicator up when opening the door to read it).

It will probably be easier to set the freezer temperature first. Adjust both the freezer and fresh food thermostats to mid-points (if the fridge is empty - otherwise skip this step). Adjust the freezer thermostat up or down as needed to reach the desired 0 degree F temperature.

Once the freezer adjustments are complete, adjust the fresh food compartment thermostat as needed up or down to reach the desired temperature for it.

If you fridge is fully stocked, it may take some time for the temperature to stabilize and warm / cool the fridge's contents completely. This is further affected by how often the door(s) are opened and for how long. 24 hours is often claimed - but you might be able to sneak an 8 - 12 hour soak before reading the thermometers.

After the temperatures are set, you may find that the lower part of the fresh food area is partially freezing - simply adjust the thermometer up *slightly* as needed.

Please rate this reply if it was helpful - good luck!

The freezer is usually cooled by the compressor, the fridge is then cooled by an evaporator fan motor ($30). If this fan seizes or slows down then the fridge warms up (it sometimes starts squealing before this happens). The fan may spin, but it if goes too slowly, then it would blow enough cool air into the fridge, especially if it is opened quite frequently.

If you think it is the evaporator fan motor:
Check to be sure you can get a replacement fan first, they last about 4 - 5 years. Can get from a parts supplier or electric motor company.
UNPLUG fridge. Located usually in top of freezer behind a vented cover plate. Remove cover, remove screws holding fan in, may have to cut wires. Replace with new motor, make sure the fan pushes air into the freezer area and doesn't spin backward drawing air from the freezer area.

Turns out the problem was because we didn't shut the freezer door tightly. The temperature re4set itself in about three hours. All OK and no expense :-)

check for frost in the freezer back wall

see if the back wall inside of freezer have ice if so you have to change tiker board or check your doors if closing

Hi dgh1,
The freezer should stay within 5 degrees of 0 while in operation. While in defrost the freezer may reach as high as 20 to 25 degrees. If any higher temperatures are reached your food will spoil as they are defrosted and refroze everyday. If you find that the temperature is allowing your food to defrost you may want to replace your defrost thermostat. This device is located on top of the evaperator coil inside the back of the freezer. It is made to turn the heater off when a temperature of 55 degrees is reached. One other possible problem could be your defrost timer is taking to long to restart the cooling cycle after defrosting. I hope this will help you and please send any other questions you may have, I am happy to help. and dont forget to rate me.
Mike Anderson
Anderson Appliance
(865)945-3808

thermistor has worned out so please change the thernistor then you ll find the temperature gets maintained in 0 degrees......

no replace the door control bd or check for a loose or bad connection on the control bd also in an abstract sense one of the freezer door switches could be bad ones for the freezer light ones a safety for the door dispenser sys but that would be rare but possible