Central Boiler e-Classic 1450 IR Owner's Manual page 15

NOTE: At least one circulation pump must run
continuously to ensure proper operation of the
outdoor furnace.
E. The circulation pump(s) must be installed in the
supply line(s) with the arrow on each pump pointed
away from the outdoor furnace. In order to avoid
circulation problems, do not install the pump(s) in
the return line(s).
F. The pump(s) must be located near the base of
the outdoor furnace if the system has a high-flow
pump or very low resistance on the outlet side of
the pump. For example, if the outdoor furnace is 20
feet (6 meters) from the building and pumping water
through one-inch pipes, a 50-plate heat exchanger
or water-to-air exchanger, and back to the outdoor
furnace, the pump needs to be mounted with four
feet of water above the pump.
The pump(s) must also be located near the base of the
outdoor furnace if operating with water temperatures
of 195˚F. Water at 195˚F will boil on the inlet side of
the pump if there is not an adequate amount of water
above the pump. This causes cavitation, indicated
by a noisy, rattling pump and results in premature
failure of the pump.
Three or four feet of water above the pump should
be adequate for systems with higher resistance
(e.g., longer loops with other fittings, elbows, heat
exchangers). For systems with low resistance (e.g.,
short loops, larger diameter pipes and low resistance
heat exchangers like a water-to-air exchanger), it
may be necessary to mount the pumps with four
to eight feet of water above the pump. See the
Hydronic Component Selection Guide (p/n 2482)
for more information.
NOTE: See the Hydronic Component Selection
Guide (p/n 2482) for more detailed information.
Fig. 12
Section 1 - Outdoor Furnace Installation
Installing the circulation pump(s) at the outdoor furnace
is recommended, but required if the building being
heated is higher than the outdoor furnace or if there is a
large rise in the water lines between the outdoor furnace
and building (see Fig. 13 and 14). Hot water boils at a
lower temperature when pulled uphill (because it is at
a lower pressure); therefore, hot water must be pushed
uphill to ensure proper circulation.
Fig. 13
Fig. 14
If not mounted on the outdoor furnace, the circulation
pump(s) must be mounted 4 to 5 feet (1.2 to 1.5 meters)
lower than the top water level in the outdoor furnace
(see Fig. 15).
Fig. 15
Water Level
Building to be heated
4 ft. (1.2 m) min.
Ground
Pump must be installed
Level
in the hot supply line,
before the heat exchanger,
and may be located inside
this building or on the
outdoor furnace.
© 2015 Central Boiler
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