2. Check the oil level. If the oil level is low, the oil burner will not be able to start. Make sure that the oil tank is full and that there is no air in the oil line.
3. Check the air filter. A dirty air filter can restrict airflow and prevent the oil burner from starting. Remove the air filter and clean it, or replace it if necessary.
4. Check the ignition system. The ignition system is responsible for igniting the oil in the burner. Make sure that the ignition wires are connected properly and that the spark plug is clean and in good condition.
5. Check the burner nozzle. The burner nozzle is responsible for atomizing the oil so that it can burn properly. Make sure that the burner nozzle is clean and free of obstructions.
6. Call a service technician. If you are unable to restart the oil burner, you may need to call a service technician.