In the continuing effort to improve the quality and consistency of gas produced from an endothermic gas generator, several enhancements have been developed and implemented to diagnose abnormal operating conditions. Typically the variables monitored, controlled, and alarmed on gas generators were limited to the temperature of the heating chamber and the dew point of the gas being generated. As instrumentation has evolved, additional monitoring has been implemented, reducing the instances of sending “bad” endothermic gas into a process critical furnace. The new diagnostic tools allow predictive maintenance to be applied to endothermic gas generators.