There may be several reasons for coffee not to stay warm:

  1. Some units have an automatic shut-off feature. This is a safety feature that would automatically shut off your coffeemaker after 1-4 hours, depending on the model. Make sure that the unit hasn't been running longer than this time.
  2. The unit may require cleaning to remove mineral deposits that build up over time and cause coffee to brew cooler than normal.
  3. If your unit has a thermal decanter, make sure that it is clean and that the lid is kept closed. The thermal decanter should keep coffee warm for 2 to 4 hours after brewing.
  4. If coffee brews cold, and if the warming plate is not getting warm, your unit may need to be repaired. Please check your warranty information, and follow the procedures for sending the unit to a service center.