Oster BVSTDC4401 Manuel D'instructions page 11

Suggested Decalcifying Interval
Type of Water
Soft Water
Hard Water
Cleaning the Glass Decanter/ Thermal Carafe
Hard water can leave a whitish stain inside the glass decanter/ thermal
carafe, and coffee may then turn this stain brown.
To remove glass decanter/ thermal carafe stains:
1. Fill the decanter/ carafe with a solution of equal parts water and vinegar
and let the solution stand in it for approximately 20 minutes.
2. Discard the solution, then wash and rinse the glass decanter/ thermal
carafe.
DO NOT use harsh abrasive cleaners that may scratch the glass
decanter/ thermal carafe.
or when red light is flashing
English-10
Cleaning Frequency
Every 80 Brew Cycles
Every 40 Brew Cycles