Steven K Saratoga Springs , NY March 12, 2016 Appliance: Maytag Refrigerator MFF2258VEA10 Maytag Refrigerator Mff2258vea10: Freezer too cold frig too warm. How to replace Defrost Heater. Replaced the Bimetl-Def control unit. Fair amount of work to take every thing out of the freezer unit to be able to open the back panel to get to the part. Replacement of part was easy. Start to finish took about 2.5 hours. 2 People found this story helpful Do-It-Yourself Rating: Repair Time Estimate: 2+ hours