Honeywell S89C Manual page 13

If the burner lights normally but goes out during the run
cycle, the gas control closes and the module initiates a
warmup period followed by one trial for ignition. If flame is
not established, the gas control closes and the module
locks out, requiring manual reset.
Three Trial for Ignition Modules
If no flame is sensed by the end of the first timed trial for
ignition, the gas control closes and the module initiates a
second 30 sec. minimum purge cycle, followed by warmup
and a second trial for ignition. If flame is not established the
START
MAIN BURNER
OPERATION
THERMOSTAT CALLS
FOR HEAT
INTERNAL SAFE START
CHECK BEGINS.
T
NO FUME
SIMULATING
FAILURE
FIG. 12—S69/S890 NORMAL OPERATING SEQUENCE.
purge, warmup, trial for ignition cycle is repeated a third
time. If flame is still not established following the third trial,
the gas control closes and the module locks out. It must be
manually reset by removing power or setting the thermo­
stat below room temperature for at least 45 sec.
If the burner goes out during the run cycle, the gas
control closes and the module checks for the number of
ignition trials performed during the current call for heat. If
the number is less than three, the module initiates a purge,
warmup and trial for ignition. After the third trial during a
single call for heat, the module locks out. The module must
be manually reset following lockout.
FUME
SYSTEM WILL
NOT START.
FAILURE
13
M 11 0A
68 0070— 1
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