Damand hot water

Here are a few photos of my propane fired demand water heater. It is made by Precision Temp, called the Shower Mate. It has several safety features which I like. When you turn on the water, it senses for water flow then senses if there is adequate forced exhaust flow. If both criteria are met, the propane flows and fires. If it fails to light, propane flow is immediately stopped. If any of the obove criteria are interupted, propane flow is stopped. I then instlled a tiny muffin fan, drawing less than 0.1 amp to draw air from the locker bottom which runs continuously (<2 amp hours per day). Finally, I installed a propane sniffer in the bilge. Propane certainly has it's detractors, but if used properly, it can be used safely.