O.Water Boiler with Intermittent Ignition (EI) and Gravity Circulation. See Figure 42.
1.Normal Operation
a.Thermostat calls for heat. Thermostat Isolation Relay is energized, closing contacts.
b.Vent Damper (if used) opens as stated in Vent Damper Sequence of Operation.
c. Ignition Module is energized. Pilot Valve opens and Igniter is energized to ignite Pilot Burner.
d.Sensor proves presence of pilot flame. Main
Valve(s) opens and ignites Main Burners.
e. After Thermostat is satisfied Ignition Module is
2.Safety Shutdown
a. Limit: Automatically interrupts main burner operation when water temperature exceeds set point. Maximum allowable temperature is 250°F. Normal operation resumes when water temperature falls below set point.
b. Blocked Vent Switch. Automatically interrupts
main burner operation when excessive vent system blockage occurs. Control is a multiple use device. If blocked vent switch is activated do not attempt to place boiler in operation. Correct source of blockage and reset blocked vent switch.
c. Flame
d. Igniter/Sensor: senses pilot flame and causes ignition module to turn off main burner and pilot burner gas flow should pilot burner flame extinguish. Five to six minutes after shutdown, Ignition Module restarts ignition sequence.
For Electronic Ignition Trouble Shooting Guide, see Page 65. For LED Status Codes, see Tables 8 and 9 on pages 55 and 56.
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