Rico in Spanish means rich in English just if your talking about money. If your talking about food rico means it's delicious, good, etc. Example, esto huele rico mean this smell good or  que Rica la comida means like delicious food in English. Puerto Rico means Rich Port in Spanish.
Tankless or demand-type water heaters heat water directly without the use of a storage tank. Heat pump water heaters move heat from one place to another instead of generating heat directly for providing hot water. Solar water heaters use the sun's heat to provide hot water.
There are several ways to flush a hot water heater, however, here's what works for me. Electric water heaters: be sure to turn the power off at the main service entrance box (circuit breaker or fuse box). If it's gas: turn the red temperature dial to vacation. At the top of the water heater tank is the cold water inlet valve. Turn it off. At the bottom of the tank is a hose bib or (drain cock).