A Certificate of Fitness is required to supervise an oil burner that is not fully automatic or requires preheating. A certificate holder must be in the building at all times while the burner is in operation. However, if the boiler in your building is fully automatic (the boiler is automatically initiated by the signal sent from a thermostat) AND not using No. 6 fuel oil, the P-99 C of F is NOT needed. This P-99 Certificate of Fitness is valid only at a specific location and for the specific person to whom it is issued.