The New Yorker Store Cast Iron-Oil Fired Boiler CL - Manual (Page 19)

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Figure 18: Wiring Diagram for Water Boilers with Beckett AFG Burner and
Split Controls with Tankless Heater
SEQUENCE OF OPERATION
A call for heat by the thermostat energizes the L7224C control which in turn energizes the primary control. The burner
will initiate ignition after completing a 15 second pre-purge cycle. If burner ignites within approximately 45 seconds
and the cad cell sees flame the burner will continue to operate until the call for heat is satisfied. The circulator will also
operate when the thermostat calls for heat if the boiler water temperature is up to the setting of the low limit in the
L7224C control. If boiler water temperature is below the low limit setting the burner will operate but the circulator will
not, giving preference to the domestic hot water demand.
On call for heat by the thermostat the burner will continue to operate until the thermostat is satisfied or the setting of
the high limit is reached. If the thermostat is not satisfied when the high limit is reached the burner will stop but the
circulator will continue to operate until the thermostat is satisfied.
Any time the boiler water temperature drops below the setting of the low limit the burner will be energized in order to
maintain domestic water temperature.