Came out today for a lock out issue on a Weil-McLain tankless boiler/hwh. Upon inspection I found that the code was for a maintenance reminder. I reset the maintenance reminder and installed a new maintenance kit (wm97+) for the system. This includes seal gaskets , igniter, flame sensor and other parts . All required parts have been replaced. I tested the system by calling for heat and then calling for hot water. Performed a combustion analysis test and received the following readings 02 is at 12%, co is at 8ppm. The system is operating properly at this time. Bill out due to no service at location.