The water is bypassing the coffee grounds due to an incorrect filter setup or clogged spray head.
- Verify you are using a #4 basket-style paper filter. The wrong size or type can cause channeling.
- Ensure the paper filter is seated properly in the basket, with the seams aligned. Folded edges should be flat against the basket.
- Check the spray head (the part that showers hot water over the grounds) for clogs. Use a toothpick to clear any debris from the holes.
- Use the correct coffee-to-water ratio: one level tablespoon of ground coffee for every 5 oz. cup of water.
If that didn't work: The heating element may not be reaching the optimal brewing temperature due to mineral scale.
- Descale the machine with a vinegar solution (1 part vinegar to 2 parts water). Run a full brew cycle, then run two cycles with clear water to rinse.
Heads up: For best results, use cold, fresh water. Avoid using distilled or softened water.