Out today 4/7/24 Trevor J. Emergency visit to look into an error code 11 on a 2016 Rinnai RL75 tankless unit. Upon arrival the code was not displaying. Ran water in home and code did not come up. Customer turned unit off and back on, I believe this reset the tankless. Unit is heating now. Ran multiple fixtures without issue. We did find a slow/ small leak coming from the cold water inlet. This tankless has also has never been descaled. I recommend we replace the cold water inlet (which will need ordered) and perform a descale on this tankless. Job Status: Complete. Estimates: Good to send.