Performed inspection to both customers drains for upstairs bathroom above garage side door as well as potable water system. Ran water for several minutes in all fixtures and was unable to identify leak. After further inspection we saw that condensation line for hvac was located above the window for bathroom and had a steady drip. I believe the water customer reported was a cause of this condensation line. Cleared primary condensation line that was located under master sink in attempt to prevent dripping from secondary line. Recommended having customer contact hvac professional to inspect system.