FIXED KFIS29PBMS02 KitchenAid Refrigerator Evap coil freezing up

[dwh]

Model Number

KFIS29PBMS02

Brand

KitchenAid

Age

1-5 years

I have a KFIS29PBMS02 double door bottom freezer. The evaporator coil in the refrigerator freezes over in about a week after defrosting. I have defrosted twice because I thought it was related to the door being left open a crack overnight. This time I have made sure the doors are closed at all times and the coil is still freezing over. I believe the fan is working because I can feel air coming from the top of the tower. The ice maker works fine and the freezer is working and the freezer coil does not have ice build up. What could be causing this if the refrigerator fan is not the issue?

 

[rickgburton]

It's usually caused by an air leak around the cover somewhere.

 

[dwh]

I am not sure what you mean. The evaporator cover is vented. I have read that sometimes the screws to the cover do not get replaced after it has been serviced. Is this the type of leak you are referring to?

 

[Jake]

Also check the refrigerator evaporator defrost thermistor that attaches to the refrigerator evaporator, it should be the copper looking one in the photo below.

To test it, you ohm it with a multimeter, you put the thermistor in cup of ice water for 5 minutes and it should read about 8.7 K ohms.

This looks like the refrigerator evaporator defrost thermistor and temperature sensor combined in one wire harness:
Refrigerator evaporator wire harness with temperature sensor


Jake

 

[rickgburton]

Correct, that evaporator doesn't use a defrost heater. When it cycles off and because it's black the frost melts almost immediately. When there's air leak it builds more frost and if it doesn't melt before it cycles back on it builds on itself.

 

[dwh]

I was able to get this apart. The two screws on the cover were missing, so I will replace those. I also ordered a replacement Refrigerator evaporator wire harness with temperature sensor and will probably replace that. I noticed there was a copper wire with some material wrapped around it that looks like duct seal. Is this normal? Does anything else look abnormal?

 

[dwh]

I replaced the thermistor and added the two missing screws. Everything appears to be working now, Thank you.

 

[rickgburton]

Awesome dwh! Thanks for the update.