Smith Cast Iron Boilers GS110W - Manual (Page 16)

GS110 DIRECT VENT BOILER INSTALLATION AND OPERATION INSTRUCTIONS Page 16
Ensure that the boiler is level from front to back and
from side to side. Use metal shims to level the boiler.
NEVER use combustible materials for shims.
Bypass Piping
CAUTION: Never connect this boiler directly to a
large volume system, in-floor radiant system, snow
melt system or any other system that would cause
the steady state water temperature in the boiler to
drop below 140
°F. To prevent damage due to
excessive condensation, one of the following piping
options must be used or the boiler warranty will be
voided!
CAUTION: The blend pump arrangement shown in
Figure 16 must be used when the flow from any
zone in a multiple zone system is less than 4 GPM
or boiler short cycling on the high limit will occur!
For the three systems listed below, adjust the bypass
valve to divert some of the heated water back into the
boiler's return piping. When adjusted correctly the
temperature of the boiler water will exceed 140
°F within
five minutes of a warm start. A plug valve should be
used as the bypass valve for best system performance.
NOTE: Some of the circulator's capacity will be used
in the blending process for the first two systems.
Large heating systems may require a larger
circulator.
System Bypass
The system bypass shown in Figure 14 should be used
on single zone systems, or multiple zone systems using
zone valves, when the circulator is installed in the return
piping. The bypass must be installed between the supply
and return pipes on the suction side of the circulator.
Figure 14 - System Bypass Piping
Pump Away Bypass
The system bypass shown in Figure 15 should be used
on single zone systems, or multiple zone systems using
zone valves, when the circulator is installed in the supply
piping. The bypass must be installed between the supply
and return pipes on the pressure side of the circulator.
Figure 15 - Pump Away Bypass Piping
Pumped Blend Bypass
The system bypass shown in Figure 16 should be used
on multiple zone systems. The bypass must be installed
between the supply and return pipes on the suction side
of the zone circulators. The bypass valve must be
installed on the pressure side of the bypass circulator.
Figure 16 - Pumped Bypass Piping