18
103536-13 - 2/24
MegaSteam
Installation & Service Manual
6. Place Right Side Jacket Panel, clearing rear
section tankless heater collar/ mounting flange,
over four #8 x ½ in. shoulder sheet metal
screws, previously installed at Front and Rear
Jacket Panel side flanges, so teardrop cutouts
in the side panel inside flanges engage all four
screws simultaneously.
7. Slide the panel downwards to lock all screws
securely.
8. Pick up Top Jacket Panel from Jacket Carton.
9. Place the panel between side panels upper
inside flanges and slide it forward, until top
panel front flange U-bend locks over front
panel top flange, and, top panel rear flange is
positioned over rear jacket panel.
10. Locate/remove two #8 x ½ in. sheet metal
screws from Hardware Bag.
11. Install both screws into top panel rear flange to
secure the top panel to rear jacket panel.
K. EXTERNAL ELECTRICAL ENCLOSURE
MOUNTING.
1. Remove two #8 x ½ in. shoulder sheet metal
screws and one #8 x ½ in. sheet metal screw
from Hardware Bag.
2. Install both #8 x ½ in. shoulder sheet metal
screws into Right Side Jacket Panel, at two
upper corners of the panel front cutout.
3. Locate and remove External Electrical
Enclosure assembly from Control Carton.
4. Remove the enclosure cover and set aside.
5. Pick Molex connector end of Burner Harness
and feed it inside the enclosure, thru bushed
hole at enclosure lower left corner, next to
transformer/relay.
6. Place the enclosure over installed shoulder
sheet metal screws, so teardrop cutouts in
the enclosure base engage both screws
simultaneously, then, slide the enclosure
downwards to lock it in place.
7. Install #8 x ½ in. sheet metal screw thru
enclosure base lower hole, located to the right
of transformer/relay, into right side panel to
secure the enclosure.
8. Plug-in burner harness Molex connector into
dedicated burner harness receptacle inside
the enclosure (lower left off transformer/relay).
See “Control Plug-In Diagram” label attached
to inside of the enclosure cover for details.
9. Do not install the enclosure cover yet; proceed
to control installation.
Figure 2-10: Pressure Limit Installation
L. TRIM AND CONTROLS INSTALLATION.
Pressure Limit Installation.
1. Locate and remove L404F Pressure Limit with
factory attached harness from Control Carton.
2. Locate and remove 1/4 in. NPT x 1-7/8 in. x 4 x
90° syphon enclosed in Part Carton.
3. Review and locate pressure limit tapping
on front section. See Table 2-9 “Purpose of
Tappings & Bosses” and Figure 2-8.
4. Thread 1-7/8 in. lg. syphon-threaded short end
into the bottom of Pressure Limit with factory
attached harness. Do not tighten the syphon
by holding the limit case; apply a wrench to the
brass hex below the case.
5. Thread ¼ in. NPT x 4 in. lg. syphon-threaded
long end into pressure limit tapping on front
section. See Figure 2-10 "Pressure Limit
Installation.
6. L404F pressure limit does not require leveling.
The pressure limit final orientation must be
parallel to boiler front, having the harness on
the right side.
7. Pick-up the pressure limit harness Molex
end and feed it into the enclosure, thru top
flange rear left 7/8 in. hole; then, snap-in
harness BX connector into the hole, and, plug
Molex connector into dedicated pressure
limit receptacle inside the enclosure (upper
left off transformer/relay). See “Control Plug-
In Diagram” label attached to inside of the
enclosure cover for details.
2
Unit-Pak Boiler Assembly
(continued)
