Greenheck IG / IGX (464104 IOM) (Pre-2009) - Manual (Page 34)

34
Start-up - Furnace (All Units)
NOTE!
There are four furnace control options available. Be sure to refer to the specific instructions for your
control type.
IMPORTANT!
Multi furnace units may use a combination of the available control options. Each furnace must be set-
up per the specific instructions for its control type.
IMPORTANT!
Multi furnace units will use one stage or modulation controller per unit and one or two ignition
controller(s) per furnace. Each furnace will have its own gas valve(s). Each valve must be set for high
and low fire.
IMPORTANT!
For the unit to function properly, all stage or modulating valves must be set for high and low fire.
NOTE!
To force the unit to light for set-up purposes, the heat switch must be closed or jumpered out. See the
ladder diagram on the inside of the control center door for proper terminals to jumper out.
NOTE!
If the unit is equipped with an independent inlet air sensor (not incorporated into the stage or
modulation controller), the unit will not light unless the outside air temperature is less than the inlet
air sensor setting. If the outside air is greater than the inlet air sensor setting, turn the setting to its
maximum position. When set-up is complete, reset the inlet air sensor to the proper temperature. If
the unit is equipped with a stage or modulation controller that includes an inlet air sensor function,
the inlet air sensor will be overridden when the unit is forced to high fire.
Available Control Options
Single Furnace Units
• 1:1 Staged (one 1-stage furnace)
• 2:1 Staged (one 2-stage furnace)
• 8:1 Staged (one 8-stage furnace)
• 2:1 Electronic Modulation (one 2:1 modulating furnace)
• 4:1 Electronic Modulation (one 4:1 modulating furnace)
Two Furnace Units
• 1:1 Staged (two 1-stage furnaces)
• 2:1 Staged (two 1-stage furnaces)
• 4:1 Staged (two 2-stage furnaces)
• 16:1 Staged (one 8-stage and one 1-stage furnace)
• 8:1 Electronic Modulation (one 4:1 modulating and one 2-stage furnace)
Three Furnace Units
• 1:1 Staged (three 1-stage furnaces)
• 3:1 Staged (three 1-stage furnaces)
• 6:1 Staged (three 2-stage furnaces)
• 24:1 Staged (one 8-stage and two 1-stage furnaces)
• 12:1 Electronic Modulation (one 4:1 modulating, one 2-stage and one 1-stage furnace)
Start-up