In this study, a high power infrared heater was implemented to preheat an H13 steel die used for high pressure die casting. The performance of the heating system was quantified experimentally by measuring die temperatures in various locations with embedded thermocouples. Heating time was reduced significantly by using a flat, stainless-steel reflector on one side of the heater. A numerical model was developed to simulate the infrared radiation heat transfer into the die. The model was validated against literature data and experimental results. The model was then used to evaluate different lamp configurations to obtain a more uniform heating distribution and to avoid hot spots on protruding surfaces. The validated model has proven to be useful in evaluating different lamp configurations tailored for specific die geometries or heating requirements.