NAVIEN HIGH EFFICIENCY BOILER 1 Gas Hot Water Boiler: Navien High Efficiency Boiler w/ x4 zones. Perform a tune-up and cleaning to help ensure reliable and safe operation. Inspect for cracks & deterioration of Heat Exchanger Check and clean Burners and heat exchanger- ok, vacuumed-ok Check and clean flame sensor and ignition Assembly-ok Check porcelain for crack or carbon buildup. Check igniter electrode gap. Check Safety Controls-ok Check electrical wiring and components-ok Check Gas valve & Gas Line-ok Check Combustion Air & Exhaust-ok Check Temperatures & Water pressure settings; 13psi Performance-ok Check and run Thermostats- operating well at this time. Remove and clean fresh air intake screen. Remove condensate trap flush with water to remove dirt and debris. Check low water cut-off, water feed, back flow, expansion tank and relief- okay Inspected all piping and zone valves. Check pressure- 13psi- okay Test DHW - operational Test all x4 zone valves and zoning panel confirming nor