wow, so many mistakes with the water heater insulation its hard to know where to start.. 1st, the insulation itself is a waste, feel the outside of any water heater, they feel cold.. they're already insulated to the hilt inside the casing. 2nd, this water heater was missing the temp & pressure relief valve discharge line, required by most local codes. 3rd, this particular model uses a sealed combusion chamber, it takes air for combustion thru the holes in the side of the water heater that you covered (then duct taped shut#.. this unit will starve for oxygen & either go out #like a candle with a lid on it) or burn dirty and produce excessive c.o. bfooter902@aol.com