Neutralizer stone Gas Hot Water Boiler: Well McLean High Efficiency Boiler- Perform a tune-up and cleaning to help ensure reliable and safe operation. Inspect for cracks & deterioration of Heat Exchanger Check and clean Burners tubes and heat exchanger- ok, vacuumed-ok Check and clean flame sensor/flame rod and ignition Assembly-ok Spark igniter. 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; 15psi Performance-ok Check and run Thermostats- operating well at this time. Check zoning operation-isolate and run zoning. Check circulation pumps-ok amps and voltage check. Check water feeder, low water cut off, expansion tank, relief valve and Venturi Check for water leak no leakage at this time. Clean and Flush condensate drain line. Clean Neutralizer pump and replace Neutralizer stones. Run and monitored for good operations. All zones are fine supply and return li