Upon arrival spoke with customer via phone. Customer granted access through garage and guided me to boiler located in the attic of the home. Navien boiler displaying error code 777. Error code for boiler having issues with LWCO Manual reset was done on the boiler but error code remain. Remove and clean fresh air intake to confirm no blockage. Clean condensate drain line and ignition assembly. Check and tested low water cut off. Add make up water to the system to fired boiler up once more. System is back up and running. Relief valve is not pipe to discharge water to domestic drain, when relief blows off water is dumping on attic floor. Spoke with customer about concern for property damage. Recommending that relief valve drain line drain to be tied into discharge line for condensate drain of hot water heater. Office to follow up with customer to provide quote View visual findings from this job here - https://visionshare.xoi.io/?id=XA-EE1C-D44650CB1FF540E5B5D1D0DD3696553B