All companies that produce Tankless Units require annual servicing of their units in order to keep the warranties valid. If you should run into a challenge with your tankless unit and you speak to a customer representative the first question they will ask is..".When was your unit last serviced? " If your unit has not been serviced at all ,these companies may reject any claims under their warranty. It Is your best interest to service your tankless unit just as you would your vehicle in order to protect your investment!!