Diagnosis
The issue is typically caused by the machine's sensors not detecting your travel mug, which triggers a safety feature to divert coffee into the drip tray instead. The Hamilton Beach FlexBrew requires a specific mug size and placement to activate the brew-through function on the single-serve side. Using the wrong settings, like the regular "Cup" mode for a small batch, can also cause this.
How to Fix It
- Check Mug Placement & Size: Ensure your travel mug is centered directly under the brew spout. The mug must be tall enough (typically 4-5 inches minimum) to trigger the internal sensor lever located inside the drip area. A short mug won't press this lever down.
- Select the Correct Brew Mode: On the control panel, press the "MUG" button for single-serve brewing into your travel mug. Do not use the "CUP" button.
- For Small Batches (1-4 cups): If you are using the carafe side to brew a small amount into mugs, you must press and hold the "SMALL BATCH" button for 3 seconds until the light stays on. This adjusts the brewing process for proper saturation and flow.
If That Didn't Work
First, test with a standard ceramic coffee mug to rule out a mug size issue. If it works, your travel mug is likely too short. If it still drips to the tray, the sensor lever inside the single-serve outlet may be stuck. Unplug the machine, lift the brew basket, and gently press the small black plastic lever several times to free it. Also, ensure the drip tray is completely empty and correctly seated, as an overfull or misaligned tray can interfere.
Heads Up
Never brew without a mug or carafe in place, as this can cause overflow and damage. The "Small Batch" mode is essential for flavor and function when brewing fewer than 5 cups on the carafe side; skipping it results in weak coffee and can contribute to dripping issues.