Aerco Modulex MLX-909 User Manual

MC2: 10/03/12 Page 51 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 9:
Maintenance
Table 9-2: Acceptable Combustion Gas Ratios at Boiler Input
GAS SUPPLY OXYGEN (O
2
)
CARBON
DIOXIDE (CO
2
)
CARBON
MONOXIDE (CO)
NATURAL GAS 4.7% to 5.3% 9.1% to 8.8% <100 ppm
PROPANE 4.4% to 5.0% 10.7% to 10.4% <100 ppm
Note that a reduction of airflow at the input may indicate the burners need cleaning, but first check the
flue outlet and the air intake for any physical obstruction. If there is no obstruction, then proceed with
the maintenance procedures starting with unit disassembly per the instructions below.
9.3.1 Unit Disassembly for a Fireside Inspection
Tools required: Phillips head screwdriver, 13mm socket wrench (with extender), and an Exacto blade (or
small sharp knife). Access to a steel brush and water jet are also recommended.
Prior to performing the following disassembly and inspection procedures,
ensure that all electrical power to the boiler has been turned OFF and
the external gas shut-off valve is fully CLOSED.
Unit Disassembly for Fireside Inspection
1. Disconnect electrical power to the unit by turning off the external circuit breaker.
2. Turn off the external gas supply shutoff valve.
3. Remove the top cover from the boiler. A screwdriver may be needed to pry the cover from the two
pins on either end. The cover is secured with spring clips and pins to the front, back and side panels
of the unit. In addition, two (2) groups of ground wires from the frame of the boiler are attached with
clips to the underside of the top cover. Use care when disconnecting these ground wire clips. Note
that all lugs have capture spring clips that are released by pressing a small nub under the lug body.
4. Remove the front panel from the boiler to provide access to the fan assembly cover (Figure 9-3).
5. Remove the screws from the various locations on the fan assembly cover. A sampling of screw
locations is shown in Figure 9-3.
6. Remove the plastic cap bolt covers (C) from the bottom of the fan chamber to access the bolts
holding the fan assembly in place (Figure 9-4).
7. Using a 13 mm socket wrench, remove the bolts D1, D2, D3, and D4 that secure the fan chamber
cover onto the burner assembly (Figure 9-5).
8. Unscrew the two air filters from each end of the burner manifold (Figure 9-6).
9. Remove the two screws and the sheet metal cover from each of two ends of the burner manifold
(Figure 9-7).
10. Position burner manifolds, at each end, 3/8” (10mm) higher than the standard position (Figure 9-8,
left). Line up the “E” hole of the gas pipe flange with the “G” hole of the side support panel and affix
with one of the two screws previously removed.
11. Lift up the fan group (L) by rotating it on the gas manifold axis and keep it up by inserting the
support rods (I), attached to the frame, in the holes (M) (Figure 9-9).
NOTE
There are six boiler models with two, three, four, five, six, or seven
burner modules. Figure 9-11 shows a Modulex MLX-606 with four
modules.
12. Access the condensate tray (N, Figure 9-10) and remove the cleaning plate (O) from the side
opposite from the flue collector (depends on which side it was originally installed). Remove the
screw securing the baffle (P) and lower the baffle onto the tray bottom.
WARNING
!
!

Aerco Modulex MLX-909 Specifications

General

Brand	Aerco
Model	Modulex MLX-909
Category	Boiler
Language	English