the mullion heater is not keeping not keeping condensation off of the mullion strip. the heater has been replaced but the condition remains. why?
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Parts for GE MTX18EABARWW Refrigerator - AppliancePartsPros.com
Looks like it has a Power Saver Switch.
Is it on or off?
Depending how they label it will depend on how it should be set.
For instance turning on Power Saver will turn off the mullion heater.
Check the freezer door seal to be sure that the bottom of it is sealing correctly.