When selling and installing tankless water heaters, it is important to first address water quality and perform regular maintenance. Historically, when dealing with tank-style heaters, flushing was recommended but few people actually carried out this maintenance. In 10 to 20 years when the tank failed, most customers chose to simply replace the unit. Tankless water heaters have small water passages that can get closed off by scaling, which can greatly affect the operation and efficiency of the heater.
Before installation of a tankless heater, water quality must be considered. According to State, a means for reducing scale is always recommended, but one must be installed if water hardness levels exceed 7 grains per gallon (120PPM) for single family domestic applications or 4 grains per gallon (70PPM) for all other applications. Removing any deposits is essential to the proper operation and longevity of the water heater. The harder the water, meaning the presence of more dissolved minerals, the more often the unit needs to be cleaned. Hot and Cold isolation service valves should be installed during heater installation to provide for the ease of system flushing and cleaning.
For proper cleaning, you will need a submersible pump, a five-gallon bucket, two washing machine hoses and an appropriate descaler that is rated for use in potable water systems. Always refer to instructions from the manufacturer on proper cleaning and maintenance of the water heater.
Regular maintenance, depending on the quality of the water, is crucial to maintaining an efficient and effective tankless water heater.