When tankless water heater units became popular in our area which again as about 2000ish, I actually think these units were fantastic, greatest thing since sliced bread (Showing my age) At that time we first installed a unit in our four bedroom four bath home to try it out. We weren’t sure if it could keep up with 2 adults and 3 babies, but it did! Tankless Water Heaters, also known as on demand-type or continuous water heaters, which provide hot water only as it is needed and therefore don’t produce the standby energy losses associated with storage water heaters, which can save you money.
Tankless water heaters heat water directly without the use of a storage tank. When a hot water tap is turned on, cold water travels through a pipe into the unit. Either a gas burner or an electric element heats the water. As a result, tankless water heaters deliver a constant supply of hot water. You don’t need to wait for a storage tank to fill up with enough hot water. However, a tankless water heater’s output limits the flow rate. The initial cost of a tankless water heater is greater than that of a conventional storage water heater, but tankless water heaters will typically last longer and have lower operating and energy costs, which could offset its higher purchase price. Most tankless water heaters have a life expectancy of more than 20 years. They also have easily replaceable parts that extend their life by many more years. In contrast, storage water heaters last 10–15 years.
I learned by reading the manual about the importance of flushing these units right off. This should be done at minimum once a year depending on the water hardness. This process is a bit different and takes quit a bit longer to complete. We also clean the ignitors and connections and a visual inspection.