Thank you for taking the time to leave a review. We hate that you're not 100% satisfied and wanted to take a moment to point out some key features of this water heater and its intended purpose. A shower uses approximately 2 gallons per minute and the water heater you purchased only holds 4 gallons of water. That will last you approximately 2 minutes or so. It has a 10-20 min recovery time, so it doesn't heat as quickly as a tankless water heater. This is a mini tank and is intended for smaller uses like sinks, hand washing stations, food trucks, etc. It's a point-of-use mini-tank water heater. You can plumb it inline with your existing water heater as a supplemental heater so that when the hot water runs out at your sink, it's filled back up with hot water from your main source of hot water, but it is not meant for larger uses like showers. That type of request depletes the 4 gallons too quickly. We stand behind our products and above all for customer satisfaction. If you have questions about this water heater and would like to chat with our team so that we can make sure you are fully happy with your purchase, don't hesitate to reach out to us at support.eccotemp.com. We will be waiting and are always happy to help!