Essential Components and How Descaling Flush Kits Work The best tankless water heater flush kits combine a submersible utility pump, color-coded hoses, a reservoir bucket, and a descaling solution to remove mineral scale from the heat exchanger. Top options include the Superior Pump 91660 for durable high-flow circulation, the Chromex kit for long-reach cords and right-angle fittings, and the Kelaro Calci-Free kit for fast, odorless chemical descaling. When choosing a kit, pr