Performed maintenance on a Rinnai RL75 tankless water heater to ensure optimal performance. Descaled the heat exchanger using a vinegar solution to remove mineral buildup, which can affect efficiency. Inspected the venting system and gas lines for any leaks or obstructions, and cleaned the water filter to ensure proper water flow. Checked the temperature settings and tested the unit to confirm it was heating water efficiently. Regular maintenance is essential for extending the life of your tankless water heater. For expert service, contact us.