Demand Water Heater

Here's a back view of the EZ 101 without the cover. Although it doesn't show here, I was concerned about temp rise and added a 140 deg thermostat in the hood at the top which I use to turn on a couple of muffin fans to increase the vertical airflow. Probably not really necessary since I didn't measure the temp coming out of the exhaust pipe that was too high (can't remember what it was)