MC2: 10/03/12 Page
37
of
90
AERCO International, Inc.
•
100 Oritani Dr.
•
Blauvelt, NY 10913
•
Ph: 800-526-0288
GF-115-H
OMM-0083_0B
Modulex MLX Series Gas Fired Boiler System
Operation and Maintenance Manual
Chap 7: Boiler
Operation
Supply Gas Pressure Check and Adjustment
1. Open the water supply and return valves to the unit and ensure that the system pumps are running.
2. Open external gas supply valve to the boiler.
3. Measure the gas pressure using the W.C. manometer connected to the inlet gas manifold. If an
external regulator is installed, adjust the pressure to 7.0” W.C. If an external regulator is not installed,
ensure the supply gas pressure is at least 4.0” W.C.
NOTE
When performing the remaining steps in this procedure, refer to
Sections 1
and
2
in Modulex E8 Controller Operation & Wiring Guide
GF-115C
for locations and
descriptions of the controls and display on the Controller
.
4. Set the ON/OFF switch on the front of the boiler to the ON position.
5. With the controller hinged panel
closed
, turn the Rotary Knob clockwise and monitor the displayed
symbols on the lower portion of the display. The symbols will increment from left to right and show the
appropriate symbols (
Figure 7-2
, below):
Standby/OFF
,
AUTO MODE 1
,
AUTO MODE 2
,
SUMMER
MODE
,
DAY MODE
,
NIGHT MODE
and finally,
SERVICE MODE
. The
SERVICE MODE
symbol
appears at the far right ( ).
6. With the
SERVICE Mode
symbol displayed, open the swing-down hinged panel of the controller.
INSTALLATION
will then be displayed.
7. Next, turn the Rotary Knob counterclockwise until
SERVICE
appears in the display.
8. With
SERVICE
displayed, press the Program Key on the Controller.
NOTE
The
CASCADE MANU
(Cascade Manual)
Mode
will time out after a period of 15
minutes. When this occurs, the boiler will revert to the
Auto
mode function under
program control.
9. Turn the Rotary Knob clockwise until
CASCADE MANU
is displayed.
10. Press the Program Key.
BOILER 1
will be displayed.
11. Press the Program Key again. The display will show
CODE NO.
, requesting valid code to be entered.
12. Enter code
0000
(4 zeros) by pressing Program Key four times. Red LED remains lit while the four
code digits are entered. LED turns off after last digit entered.
13. With
BOILER 1
displayed, press the Program Key. The red LED will light.
14. Turn the Rotary Knob clockwise and select a fire rate of 100%. Press the Program Key to store the
100% fire rate.
15. Wait until Boiler stage fires at 100% fire rate.
16. Next, turn the Rotary Knob clockwise until BOILER 2 is displayed.
17. Repeat steps 13 to 16 for each Boiler stage.
18.
With all Boiler stages firing at 100%, check inlet manifold gas pressure.
Verify pressure is at least 4.0” W.C.
19. If the gas pressure is less than 4.0” W.C., contact your gas supplier.
DO NOT proceed until the
supply gas pressure is corrected.
20. If the gas pressure is adequate at full-fire, close the hinged panel of the controller.
21. Set the ON/OFF switch on the front of the boiler to the OFF position.
22. Turn off the gas supply to the boiler by closing the external shut-off valve.
Remove the manometer from the gas manifold pressure tap. Close the tap by rotating the adjustment
screw fully clockwise to its stop. This manometer will be used to measure gas valve outlet pressure for
each stage during the Combustion Calibration procedure in
Paragraph 7.5.5
on next page.
