Sec. 4-11.6. Automatic—maximum firing rate over 33 gallons per hour

The main flame trial-for-ignition period shall not exceed 30 seconds when the burner has a low firing rate start under 16 gallons per hour and shall not exceed 15 seconds when the burner does not have such a low firing rate start. The main flame shall be supervised continually while the burner is firing. The electrical circuit to the main fuel valve shall be automatically de-energized within four seconds after flame failure and the de-energized valve shall automatically close within the next five seconds. The burner may make one attempt to relight automatically during this flame failure reaction time before the valve closes.