GSHA Services, LTD performed annual maintenance on a Rinnai condensing tankless water heater for a homeowner in Elgin, IL. Our plumber isolated the unit with the service valves, circulated a descaling solution through the heat exchanger with a flush pump for a full hour to dissolve hard-water scale, cleaned the cold-water inlet filter screen, checked the venting, condensate line, and gas pressure, and verified the unit fired and modulated correctly before returning it to service. Regular descaling keeps a tankless water heater efficient, prevents error codes and flow loss, and protects the manufacturer warranty, which is especially important with the hard well and municipal water common in the Fox Valley. Need tankless water heater maintenance, descaling, or repair in Elgin, South Elgin, St. Charles, or Kane County? GSHA Services services Rinnai, Navien, and Noritz tankless units across the western Chicago suburbs.