Lennox International Inc GWB8-299E-2 A.5 Operation, Operation State Codes, Definition, Explanation

APPENDIX A - CONTROL MODULE

A.5 Operation

Module continuously monitors boiler water temperature and fires or shuts off burner based on this temperature data.

1.When “Call for Heat” occurs, control enables circulator and monitors boiler water temperature to determine whether thermostat can be satisfied without firing burners.

2.Control determines burner operation is required,

module proceeds to start burner (see state codes list) and heats water in boiler until setpoint temperature is achieved or thermostat is satisfied. .

3.Burner is de-activated, ignition module completes heat- ing cycle, returns to idle and waits for temperature to drop again.

4.Circulator is turned on throughout “Call for Heat.”

		Table 6 - Operation State Codes
State
Code	Definition			Explanation
Number
	Idle		Standby - no call for heat
1	Circulator		Heat request present. Boiler temperature sufficiently high to run circulator
			pump only.
4	Pre-purge		System is purging before ignition trial; includes Pilot Valve circuit diagnostics.
6	Spark		System sparking. Flame is not present up to 13 seconds
7	Flame stabilization		Flame signal is being established. Variation in signal is allowed during this
			state, flame must be stable at end of period
8	Running		System is running. Flame signal must be present.
9	Post-Purge		System is purging at end of call for heat
	Retry Recycle Delay		Successful ignition was not detected, and delay is called before retry.
10			Flame signal was lost during state 7 or 8, and delay is called before retry (32
			second delay)
13	Soft lock-out		Soft lockout duration is one hour, may override with manual reset.
14	Hard lock-out		Manual reset is required for hard lockout
15	Wait for limit to close		Possible thermostat call for heat; limit switch is open.
			Flame signal sensed before trial for ignition. Appropriate alarm is sent.
				OR
16	Flame out of sequence		Flame signal sensed out of sequence during post purge. Appropriate alarm is s
			ent.	OR
			Flame signal present when not expected. Appropriate alarm is sent.
	Pilot valve diagnostics		Pilot valve circuitry diagnostics during pre-purge.
	Current leakage detection		Self check performed at start up, again at beginning of heat cycle, and during
17			“Wait for Recovery “ State.
	Wait for recovery		Self check performed at start up, again at beginning of heat cycle, and during
			“Wait for Recovery “ State
			Control has signaled damper/pressure switch
18	Wait for damper to open		to close, and is waiting for completion.
			If damper/pressure switch does not close within 60 seconds, control goes to
			State 20.
			Damper is closed and control waits for damper to open.
19	Wait for damper to close		Checked at beginning of heat cycle before opening damper.
			If damper does not open in 60 seconds, control goes to State 21.
20	Wait for damper to open		Damper has not opened (end swich not closed) at beginning of heat cycle.
	(Failed close)		Alarm message is sent, control is NOT in lockout.
21	Wait for damper to close		Damper has not closed despite actuator de-energized.
	(Failed open)		Alarm message is sent, control is NOT in lockout.

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