Abstract: A combustion chamber for a chiller includes a burner and igniter which are maintained in the horizontal position. The horizontal positioning is implemented by a steel casting, which includes a thick flange portion. The thick flange portion is between the combustion chamber and the outside surface, therefore keeping the outside surface cooler. The steel casting has a mitered extension of the combustion chamber, which allows for more efficient heat transfer. By orienting the burner and igniter in the steel casting in the horizontal position, one eliminates prior art ceramic annular cooling devices. The horizontal orientation enables the overall height of the generator to be decreased and also allows for easy access during installation and maintenance of the burner and igniter.