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HomeRepair HelpBosch Refrigerator RepairBosch Refrigerator has frost or moisture buildup around the door Repair
Bosch Refrigerator has frost or moisture buildup around the door
Frost or moisture around the door mullion usually means warm, humid air is getting past the seal or the small heater that keeps the mullion dry has stopped working. The most likely culprit is a defective mullion heater; you can test it for electrical continuity with a multimeter and replace it if it shows open. Next check for a damaged or misaligned door support or door guide that prevents the mullion flap from closing tightly. A twisted, torn, or worn door gasket is another common cause because gaps let warm air in and can lead to the freezer not freezing properly. If the door was left open for several hours, accumulated frost often clears after a defrost cycle, but repeated moisture means a seal or heater problem. If you suspect the fridge door not sealing or the refrigerator door not closing properly, inspect those parts and replace as needed. Enter your model number at RepairClinic.com to find the exact replacement mullion heater, door support, door guide, or gasket that fits your refrigerator.
01 - Bosch Refrigerator Mullion Heater
A defective mullion heater flap may not be able to heat up periodically to melt any frost or moisture that forms on the flap due to increases in room humidity. You can use a multimeter to test the mullion heater for electrical continuity to determine if the component is working. If the mullion heater has no electrical continuity you should replace it with a new one.
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Common
02 - Bosch Refrigerator Door Support
If the mullion heater flap has frost or moisture buildup, it's possible the door suport is damaged or misaligned and not allowing the flap to form a tight seal between the refrigerator doors. Inspect the door support for wear or damage and replace if necessary.
Common
03 - Bosch Refrigerator Door Guide
If the mullion heater flap has frost or moisture buildup, it's possible the door guide is damaged or misaligned and not allowing the flap to form a tight seal between the refrigerator doors. Inspect the door guide for wear or damage and replace if necessary.
Common
04 - Bosch Refrigerator Door Gasket
A door gasket should form an airtight seal around the appliance's frame to keep the cold air in and the warm air out. If the door gasket is twisted or torn, gaps can form that will allow warm air in, resulting in the freezer not freezing properly. Inspect the door gasket for any damage and replace with a new one if necessary.
Common
05 - Refrigerator or freezer door left open
If the freezer or refrigerator door was left open for an extended period of time (more than 4 hours), frost may have accumulated on the food and around the door opening. The frost should go away after the door is closed and the refrigerator goes through a defrost cycle.
Common
Frequently Asked Questions
Fridge not cooling but freezer works — why is the freezer cold but the fridge warm?
Refrigerator not cooling: could the mullion heater or door gasket be the cause?
How can I test the mullion heater to see if it needs replacing?
Refrigerator not defrosting: I left the door open and now there is frost around the door — will it clear on its own?
How do I enter my model number or part number on RepairClinic.com to find and buy the correct replacement part?
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