Instruct: Classify a given Amazon review into positive or negative sentiment.
Query: Quality control problems

We had one of these for about a year and a half. Then it went bad. It would not stay on. At times, it would turn off every few seconds after the switch was pushed to "on." It did make decent coffee so we decided to get another. We have had it for about 2 weeks, but it only worked correctly the first 3-4 times we used it. Then it started making terrible gurggling noises for about 10 minutes near the end of every brew cycle. Now, the self-clean light comes on every few times it is used, indicating it is full of calcium deposits. However, we have very soft water, and the previous unit never required cleaning because of deposits. Meanwhile, we put up with the gurgling so we can have our morning coffee. Other than that, the coffee tastes fine.