Freezer is getting too warm

Hi @alexrivlin

If the refrigerator temp is OK but the freezer temp isn't, check that the dispenser door assembly is OK. (supplier example only to show part and has a video as well).

if it isn't closing properly it may be allowing warmer air to enter the freezer compartment thereby raising the temp.

If it is faulty and needs replacing, search online for WR17X11653 to find suppliers that suit you best.

@alexrivlin

Not sure if they're the same as a ZISB42 series but looking at the ZIS42 series service manual there is a delay thermostat associated with the evap fan, perhaps that is faulty. (see following page in manual I linked for location to check).

The parts suppliers I checked for your model don't mention it as a spare part, (they also don't mention it for the ZIS42 models either) only the defrost thermostat,

Perhaps it has markings on it that will help to find a replacement if it is faulty. Reading the description of operation and seeing an image of the thermostat it seems very similar to a bi-metal defrost thermostat in that usually they also operate at ~45°F to open the defrost heater circuit and close again at ~25°F to re enable the circuit after a defrost cycle has been completed to close the heater circuit again in readiness for the next defrost cycle.

You may even find that it is identical to the defrost thermostat in the freezer. If it is search online for WR50X45 to find suppliers that suit you best.

Here's a link that shows how to test bi-metal thermostats.