Ignition Control There will be voltage at point 8, which is the “MVP” terminal of the ignition control, only when there is an attempt to ignite the burner or when the ignition control’s f lame sensing system has determined that it is OK to allow burner operation. Even if voltage has been confirmed at point 7, the “trial for ignition” sequence is imposed by the ignition control. This sequence consists of a 15 second period of pre-purge blower operation, a 40 second period for heatup of the igniter and a 7 second trial for ignition, during which there is voltage at point 8. If satisfactory ignition is not achieved, the igniter is turned off and the blower is operated for a 45 second post-purge. The system may go through this cycle as many as three (3) times, but thereafter it is “locked out” by the ignition control. Additional attempts will be made only if the call for heat is interrupted by turning off electrical power or setting the control to “Off”.To trouble shoot the ignition control, connect the voltmeter probe at point 8 and set the control to call for heat. Observe that the normal sequence takes place by noting blower operation, the glow of the igniter through the combustion chamber sight glass and then voltage at point 8. If the blower does not operate or the igniter doesn’t glow, investigate as outlined in a later sections. If both of these components operate normally but voltage doesn’t appear at point 8 during the trial for ignition, replace the ignition control. If voltage appears at point 8 but there is no ignition, proceed to analysis of other components.