S8610U UNIVERSAL INTERMITTENT PILOT GAS IGNITION CONTROL
17
69-1955
Failed Trial for Pilot Ignition
The S8610U control module provides multiple trials for
ignition (TFI). If the pilot is not lit or sensed before the end
of the trial for ignition time, the ignition control shuts off
the spark and pilot gas (100% shutoff). There is a five
minute delay before another TFI is initiated. The pattern of
TFI followed by a five minute delay continues until the
pilot lights and is proved or the “Call for Heat” ends. The
five minute delay time can be bypassed by cycling the
system thermostat or removing and restoring system
power.
The following operating sequence includes vent damper
operation (if connected) and Prepurge (if configured).
Fig. 8. Normal Operating Sequence.
OPERATING SEQUENCE
“CALL FOR HEAT”
RECEIVED FROM
THERMOSTAT
POWER TO
MODULE AND
SELF CHECK
IDLE
(NOT POWERED)
RUN
YES
TRIAL FOR
IGNITION
(TIMER STARTED)
SPARK ON
OPEN PILOT GAS
VALVE
FLAME
PROVED?
FLAME
STABILIZATION
(2 SECONDS)
YES
NO
RETRY
OPEN MAIN GAS
VALVE
CLOSE MAIN GAS
VALVE AND PILOT
GAS VALVE
FLAME
LOST?
NO
CLOSE PILOT
GAS VALVE
SPARK OFF
“CALL
FOR HEAT”
ENDS?
YES
NO
RETRY DELAY
(5 MINUTES)
SPARK OFF
A
B
MORE THAN
5 FLAME LOSSES
IN THIS “CALL
FOR HEAT”?
YES
(BEFORE TRIAL FOR IGNITION TIMER EXPIRES)
A
CLOSE MAIN GAS
VALVE AND PILOT
GAS VALVE
M23588
IF CONFIGURED,
BEGIN PREPURGE
(30 SECONDS)
DAMPER
CONNECTED?
DE-ENERGIZE
(CLOSE) DAMPER
DAMPER SWITCH
OPENS IN 60 SEC.?
1
IF DAMPER CONNECTED AND DAMPER SWITCH IS OPEN, IGNITION CONTROL CLOSES PILOT
AND MAIN GAS VALVES (IF OPEN), TURNS SPARK OFF (IF ON), AND GOES TO CHECK STATUS
OF DAMPER SWITCH.
CHECK STATUS
OF DAMPER SWITCH
YES
YES
NO
NO
DAMPER SWITCH
CLOSES IN 60 SEC.?
YES
NO
1
1
1
1
NO
1
B