Hello Concetta, Thank you for your inquiry! We strive for excellence in both the customer service, as well as the quality of the product. Though we have seen some units being sensitive to water level, we have sold nearly 150,000 devices and are proud to say that 96% of the users that participated in our survey, would recommend MyPurMist to others. We are very sensitive to our customers' satisfaction and always go above and beyond to resolve any issues in a timely manner. Admittedly, in the last month or so, we have seen some delays in responding to the customers due to a customer service and technical support transition. However, this process has been completed already and we are ready to respond to any inquiries or answer any questions you may have. Sincerely, MyPurMist Customer Care