What C1 Means
C1 is the code Bosch reserves for a cooling cycle that is not working. The repair manual defines it precisely: the compressor has run for more than three hours while a defrost sensor still reads above 23 degrees Fahrenheit, which means the compressor is working but the evaporator is not getting cold. The check point the manual gives is refrigerant leakage.
Common Causes of C1
- Refrigerant leak in the sealed system
- Compressor running but not pumping
- Restriction in the sealed system preventing proper flow
🔧 One Safe Check You Can Try
There is no home fix, but there is a useful observation: feel whether the compressor at the back is running warm and vibrating while the freezer stays soft. That combination, a machine clearly working and a cabinet that will not cool, is what this code describes.
⚠ Why You Shouldn't Go Further Than That
- Sealed-system work requires certified handling of refrigerant, which is a legal requirement rather than a matter of skill.
- A compressor that has run continuously for hours is hot enough to burn and its start circuit holds charge after power is removed.
- Topping up a leaking system without finding the leak is a temporary result at best and vents refrigerant into the atmosphere.
- Food safety comes first here: move perishables somewhere cold rather than waiting to see whether the cabinet recovers.
Opening a panel to inspect or repair something yourself doesn't automatically cancel your manufacturer's warranty — but it can risk accidental damage, and some manufacturers do have specific service conditions. Check your product's warranty terms, or ask us, before deciding.