A combustion heater includes a combustion chamber having a burner input port and a heat output port. A burner is coupled to the burner input port, whereby heat is generated within the combustion chamber. A heat exchanger is provided having an inlet and an outlet. The inlet is coupled to the heat output port of the combustion chamber. The heat exchanger consists of two hollow corrugated cones secured in base to base relation with opposed apexes. This form of heat exchanger is capable of withstanding high temperatures when directly coupled with the combustion chamber and serves to make any combustion heater with which it is coupled more efficient.