Tankless water heaters save energy. With a standard water heater, you heat & re-heat the same water all day & night. With tankless water heaters you only heat water when you need it & for as long as you want, cutting heating & energy costs. They save space. Most tankless water heaters are compact in design, about the size of a small suitcase. Some can be wall hung.
Water heater flushing eliminates sediment build up. Sediment is small bits of dirt, rock and other debris that works its way into your water heater over time. Being heavier than water, it will settle to the bottom of the tank. Sediment buildup can potentially decrease the amount of hot water the tank can hold, or it can clog up the drain valve. Bacteria can also grow in the older tanks causing a sulfur or rotten egg odor. Plumbing Plus is not only experienced in flushing water heaters, but will provide you with a timing recommendation for future flushing.
http://www.sdge.com/business/rebatesincentives/ for more information on SDG&E HVAC Rebates.