There have been 3E problems of energy, economy and environment since the earth has its history. Especially, the energy and environment problems have been getting serious after the modem industry revolution. Therefore, the demand of gas as an eco-friendly energy source is getting increased. With the demand of gas, the installation and use of gas boiler is also increased, so human life injury by the waste gas(CO) of boiler goes on increasing every year. It is the content about a life of the exhaust tube which is used at Gas boiler in this paper. We explain also the course to apply the 6SC(6 Step Creativity)of practical TRIZ and evaluate the resolution.