AERCO BMK 3.0 LN Dual-Fuel Series Gas Fired Low NOx Boiler System - Manual (Page 13)

INSTALLATION
2-3
2.4.3 Removal of Support Rod
Prior to installation of water supply and return
piping, the 24” threaded rod shown in Figure 2-3
must be removed. This rod is installed prior to
shipment from the factory to prevent damage to
the insulated metal flex hose on the hot water
supply outlet of the boiler. In order to install the
water supply piping, this rod must be removed
as follows:
1. Refer to Figure 2-3 and back off the hex nut
on the outlet side of the flex hose.
2. Next, disconnect the coupling nut from the
flange stud.
3. Completely remove the threaded rod, hex
nut and coupling nut from the boiler.
5/8-11 x 24" LONG
THREADED ROD
5/8-11
HEX NUT
5/8-11
COUPLING NUT
EXHAUST
MANIFOLD
OUTLET
FLANGE
INSULATED
FLEX HOSE
(SEE IMPORTANT
NOTE BELOW)
PARTIAL TOP VIEW - REAR
Figure 2-3
Location of Threaded Support Rod
IMPORTANT
THE INSULATED FLEX HOSE
SHOWN IN FIGURE 2-3 MUST BE
LEVEL OR SLOPING UPWARD AS
IT EXITS THE BOILER. FAILURE TO
PROPERLY POSITION THIS HOSE
MAY CAUSE INEFFECTIVE AIR
ELIMINATION RESULTING IN ELE-
VATED TEMPERATURES THAT
COULD COMPROMISE THE TOP
HEAD GASKET.
2.4.4 Removal of Strap and Packing
Material From Heat Exchanger
Prior to connecting the external gas supply or
electrical power to the unit. the strap and
packing material must be removed from the top
of the primary heat exchanger. This material is
located in the area of the ignitor-injector and
staged ignition solenoid on the burner assembly
This can be easily accomplished by removing
the top panel nearest to the front of the unit.
2.5 SUPPLY AND RETURN PIPING
The Benchmark 3.0 Dual-Fuel Boiler utilizes 4”
150# flanges for the water system supply and
return piping connections. The physical location
of the supply and return piping connections are
on the rear of the unit as shown in Figure 2-4.
Refer to Appendix F, Drawing AP-A-811 for
additional dimensional data.
REAR VIEW
BOILER SUPPLY
4" – 150# FLANGED
CONNECTION
EXHAUST
MANIFOLD
SHELL
DRAIN
VALVE
BOILER RETURN
4" – 150# FLANGED
CONNECTION
2" NATURAL
GAS INLET
CONNECTION
2" PROPANE
INLET
CONNECTION
Figure 2-4
Supply and Return Locations
2.6 CONDENSATE DRAINS
The Benchmark 3.0 Dual-Fuel Boiler is designed
to condense water vapor from the flue products.
Therefore, the installation must have provisions
for suitable condensate drainage or collection.
Two condensate drain connections are provided
on the rear of the unit as shown in Figure 2-5.
One drain connection is located on the exhaust
manifold and the other is located on the
connecting manifold.
The drain at the bottom of the exhaust manifold
also includes a condensate trap containing a
float assembly. When condensate collects in the
exhaust manifold, the float rises, thereby
allowing it to discharge through the drain
opening. The drain pipe located on the
connecting manifold must be connected to a
second condensate trap which is packed
separately within the unit’s shipping container.