These generators are relatively thirsty and require more pressure on the line than other gas appliances such as stoves or heaters. It's quite possible that the natural gas service isn't sufficient to run the generator without being upgraded. Since I have two propane tanks already I decided to power the generator from those. They should provide about 4.5 days worth of power and keep me completely off the grid. I heard that during Hurricane Isabel a number of areas had problems with natural gas supplies.