AERCO KC1000 Boiler equipped with Mod-Box Controller - Manual (Page 22)

CONTROL PANEL OPERATING PROCEDURES
17
3.10 AFTER FLAME
Once the control signal has gone below the stop
level (see section 3.12 for Stop Level
explanation), the temperature controller’s green
ON light extinguishes, indicating there is no
longer a call for heat. This signals the
combustion safeguard to shut down the burner.
The POWER LED of the combustion safeguard
remains illuminated and the annunciator
displays the message STANDBY.
3.11 FLAME TEST JACKS
The front of the combustion safeguard has two
test jacks marked + and - for flame monitoring,
(see Fig. 3.15). To access the test jacks remove
the combustion safeguard cover by turning the
center screw counterclockwise. A standard
voltmeter is required to monitor the flame signal
strength. A flame signal of 5VDC is typical
during proper operation of the unit.
Figure 3.15
Flame Test Jack Location
3.12 START STOP LEVELS
The start and stop levels are the firing rate
percentages that represent a call for heat and an
indication that the call for heat has been
satisfied. The start level is preset to 20% and the
stop level is preset to 16%. These are factory
preset and should not require adjustment.