This video shows the build of a DIY solar powered, pressurized, roof top water heater and shower.This is done using an ABS 4 inch pipe, 6 feet long, which would give me a capacity of 15 Litres or 4 US gallons.This is an easy and inexpensive project that required minimal tools and just some basic plumbing parts.I started by installing the shutoff valve. I wanted the drain to be as low as possible in the pipe to avoid necessity of having to tilt the system. To ensure the valve retaining nut did not interfere with the pipe once it is glued into the, I positioned the nut away from the wall of the cap using a bolt, which is the same thickness as the wall of the pipe.I drilled out a 2” threaded cap and tapped in a radiator valve drain plug that I picked up at the local automotive parts store. This valve will allow me to release pressure from the tank should that be necessary without opening the drain shutoff. Also when open, this will allow a gravity fed system through the drain valve should for some reason I not have access to the air compressor.As a final step to improve thermal absorption of solar energy, I painted the surface with flat black paint. First I lightly buffed all the ABS surfaces with steel wool soaked Methol Hydrate. Then applied one coat of spray primer followed by two coats of flat black paint.