Greenheck IG / IGX (464104 IOM) (Pre-2009) - Manual (Page 38)

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Step 3 Send the Unit to Low Fire
Disconnect and isolate the wire from the high fire terminal to send the unit to low fire.
WARNING!
Once the high and low fire have been set, be sure the press the escape key to end high fire mode. The
display will stop flashing “HIF” when high fire mode is off.
Step 4 Check the Low Fire Manifold
Pressure
Measure each valve’s low fire manifold pressure.
The recommended low fire manifold pressure is 7 ⁄
8
inch
wc for natural gas and 2 1 ⁄
2
inches wc for LP.
If needed, use the low fire adjustment screw on each
staged gas valve to properly set both low manifold
settings. Counterclockwise rotation will decrease the
gas pressure and clockwise rotation will increase the
gas pressure.
When the low fire manifold pressure is properly set,
reattach the disconnected wire to the high fire
terminal, allow the heat switch to close or remove the
jumper (see step #1).
Start-Up - 8:1 Staged Control
Eight Stage Manifold
Pressure (inches wc)
Natural Gas LP
Low Fire 7 ⁄
8
2 1 ⁄
2
High Fire 3 1 ⁄
2
10
Low Fire
Adjustment
High Fire
Terminal
Start-Up