FloAire INDIRECT FIRED BENT TUBE MODULE - Manual (Page 18)

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7. Using buttons #1 and #2, adjust the low fire manifold pressure to 0.15 in. w.c. for natural gas and
.75 in. w.c. for propane gas.
8. Save the low fire setting by simultaneously holding down buttons #1 and #2 until the blinking LED
turns off. Press any button on the FVFAB to exit low fire mode or reconnect the wires leading
from the thermostat to the discharge air sensor.
9. There are 3 dip switches on the Maxitrol modulating valve. All switches should be in the “OFF”
position. In the image above, all three dip switches are shown in the “OFF” position.
10. Replace the cap to the Maxitrol modulating gas valve and all pressure regulator adjustment caps
on the ON/OFF gas valves.
11. If necessary, reconnect the wire to the discharge air temperature sensor and set the dipswitch
settings on the thermostat back to space control mode if these were changed during step # 2.
12. A final gas leak check shall be performed to verify the gas-tightness of the heater’s components
and piping under normal operating conditions.
Gas Pressure Adjustment Reference Information (Natural Gas)
# of Furnaces in Unit
1 Furnace 2 Furnaces 3 Furnaces 4 Furnaces
G
a
s
V
a
lv
e
Re
g
u
la
to
r
S
e
tti
n
g
s
1st Furnace
(Modulating)
ON/OFF Valve Fully Open
Maxitrol Modulating
Valve @ 3.5" w.c.
ON/OFF Valve Fully Open
Maxitrol Modulating
Valve @ 3.5" w.c.
ON/OFF Valve Fully Open
Maxitrol Modulating
Valve @ 3.5" w.c.
ON/OFF Valve Fully Open
Maxitrol Modulating
Valve @ 3.5" w.c.
2nd Furnace
(ON/OFF or
Modulating)
N/A
ON/OFF Valve Fully Open
Maxitrol Modulating
Valve @ 3.5" w.c.
ON/OFF Valve Fully Open
Maxitrol Modulating
Valve @ 3.5" w.c.
ON/OFF Valve Fully Open
Maxitrol Modulating
Valve @ 3.5" w.c.
3rd Furnace
(ON/OFF)
N/A N/A 3.5" w.c. 3.5" w.c.
4th Furnace
(ON/OFF)
N/A N/A N/A 3.5" w.c.