Honeywell ST9141A1002 User Manual page 5

ST9141A1002 Operating Sequence (Continued)
Action
Primary limit switch string closes.
Primary limit switch string is open
for more than 150 seconds (on each
of three consecutive cycles).
Burner limit opens.
Burner limit closes.
Electronic air cleaner is connected.
(Connector to 120 Vac electronic
air cleaner.)
Humidity control is connected.
(Connector to 120 Vac humidifier.)
System Response
• Circulating fan turns off after the selected heat fan off delay timing.
• LED stops flashing.
• Normal operation resumes.
• Combustion air blower, circulating fan and ignition system are de-energized.
• Control goes into lockout mode.
• LED flashes four times.
• Control remains in lockout until 24V power is removed and reapplied (control
is reset).
• LED stops flashing.
• Normal operation resumes.
• Thermostat and ignition system are de-energized and gas valve closes.
• Combustion air blower and circulating fan heat speed are energized.
• LED flashes once.
• Combustion air blower remains energized for postpurge timing.
• The circulating fan remains energized for the selected delay off timing.
• LED stops flashing.
• Normal operation resumes.
• Electronic air cleaner is energized when the circulating fan heat or cool speed
is energized.
• Humidifier is energized when combustion air blower is energized.
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