the 'clean' light on my cm1160b is on and won't go off, how do i reset it?

Diagnosis

The "Clean" indicator light on the Black+Decker CM1160B is not triggered by a sensor that detects mineral buildup or dirt; instead, it is controlled by a digital cycle counter embedded in the control board. Once the machine has completed approximately 30 to 60 brew cycles (depending on the specific manufacturing run), the logic board triggers the LED to alert the user that a descaling process is necessary to maintain heating element efficiency. Because this is a timer-based alert, the light will remain illuminated even if you have recently descaled the machine using a third-party solution or if the water in your area is exceptionally soft. The light will only extinguish once the machine registers the completion of a full "Clean" cycle initiated through the specific button sequence. If the cycle is interrupted or the water reservoir runs dry before the process finishes, the counter will not reset, and the light will persist.

How to Fix It

To reset the indicator light, you must execute the dedicated cleaning sequence. Follow these steps precisely to ensure the control board registers the cycle as complete:

1. Empty the coffee basket and remove any old grounds. Insert a fresh, clean paper filter into the basket to catch any loosened mineral deposits during the process.
2. Fill the water reservoir to the 12-cup maximum fill line. For a more effective cleaning, use a mixture of equal parts white distilled vinegar and water, or a commercial descaling solution.
3. Ensure the carafe is empty and properly seated on the warming plate.
4. Locate the 'Clean' button on the control panel. Press and hold the 'Clean' button firmly for 3 to 5 seconds. You will know the mode has engaged when the 'Clean' light begins to blink.
5. Allow the machine to run the entire cycle without interruption. The machine will pump the water through the heating element and showerhead at a slower, controlled rate than a standard brew.
6. Once all the water has passed through the carafe and the machine automatically shuts off, the 'Clean' light will extinguish.
7. Run two additional cycles with plain, cold water to rinse out any remaining vinegar or descaling chemicals before brewing coffee again.

If That Didn't Work

• Power Cycle the Logic Board: If the light stays on after a successful cycle, unplug the unit from the wall outlet for at least 60 seconds. This clears the temporary memory (RAM) of the control board. Plug it back in and attempt the 5-second hold of the 'Clean' button again.
• Check for Water Flow Obstructions: If the cycle stops prematurely, the machine may think it has finished. Check the showerhead (the spray area above the filter) for calcium buildup. Use a needle or a toothpick to clear the small holes. If water cannot flow freely, the cycle timer may glitch and fail to reset the light.
• Verify Button Engagement: On some CM1160B units, the tactile switch under the 'Clean' button can wear down. Ensure you are pressing the button fully until you feel a physical click. If the light doesn't blink, the signal isn't reaching the board.
• Hard Reset via Water Level: Ensure the reservoir is filled to the absolute maximum. If the water level is too low, the heating element may overheat and trigger a safety shut-off before the "Clean" timer reaches zero, leaving the light on.

Heads Up

• Avoid using bleach or abrasive chemicals in the reservoir; these can corrode the aluminum heating tube and permanently damage the internal seals.
• If you live in a hard-water area, perform a manual vinegar rinse every 30 days regardless of whether the light is on to prevent the heating element from burning out.
• Always use distilled or filtered water to extend the time between "Clean" alerts and prevent the showerhead from clogging.
• Never leave the machine plugged in when not in use for long periods, as this can lead to phantom power draw and occasional glitches in the cycle counter.