caption: The image shows a diagram of a water heater, with labels indicating the various components of the water heater. It includes a tank, a filter, a sand filter, and a water source. The tank is connected to the water source by a series of pipes and valves, and the filter is used to filter the water. The sand filter is then used to collect the water from the water and then to filter it back into the tank. The water source is then released into the water, which helps to keep the water clean and free of contaminants.