Install Instructions

4 Hydronic piping (continued)
27
Installation & Service Manual
Hot water pip ing must be supported by suitable hangers or
floor stands, NOT by the boiler. Copper pipe systems will be
subject to considerable expansion and con trac tion. Rigid pipe
hangers could allow the pipe to slide in the hanger resulting in
noise transmitted into the system. Padding is recommended
on rigid hangers installed with a copper system. The boiler
pressure relief valve must be piped to a suitable floor drain.
See the relief valve section on page 24 of this manual.
 CAUTION
A leak in a boiler system will cause the
system to intake fresh water constantly,
which will cause the tubes to accumulate
a lime/scale build up. This will cause a
NON-WARRANTABLE FAILURE.
Water Connections Heating Boilers Only
All water heaters and heating boilers with inputs of 315,000 -
500,000 Btu/hr have 2" NPT.
 CAUTION
Field installed reducing bushings may
de crease flow re sult ing in boiler noise or
flashing to steam.
Circulator Pump Requirements
This is a low mass, high efficiency hot water boil er which
must have adequate flow for quiet, efficient op er a tion. The
boiler circulating pump must be pur chased locally. The boiler
circulator pump must operate con tin u ous ly while the boiler
is firing. Pump selection is critical to achieve proper op er-
a tion. A pump should be selected to achieve proper system
design water temperature rise. A heat ex chang er pressure
drop chart (Table 4C) is provided to assist in proper pump
selection. Also provided is a System Temperature Rise Chart
(Table 4B). This table provides GPM and boiler head-loss
at various temperature rises for each boiler based on Btu/
hr input. Temperature rise is the difference in boiler inlet
temperature and boiler outlet temperature while the boiler is
firing. Example: The boiler inlet tem per a ture is 160°F and the
boiler outlet temperature is 180°F, this means that there is a
20°F tem per a ture rise across the boiler.
Circulator Pump Specifications
1. Maximum operating pressure for the pump must exceed
system operating pressure.
2. Maximum water temperature should not ex ceed
nameplate rating.
3. Cast iron circulators may be used for closed loop
systems.
4. A properly sized expansion tank must be in stalled near
the boiler and located on the suction side of the pump.
TABLE - 4C
HEAT EXCHANGER PRESSURE DROP CHART
CB
3
CB 399
3
4
5
6
7
FT/HD
CB
3
CB
399
0
1
2
3
4
5
6
7
0 5 10 15 20 25
FT/HD
Gallons per Minute
315
CB 360
CB 500
315
CB
360
CB 500
30 35
Circulator Pump Operation (Heating Boilers
Only)
Boilers are equipped with a relay for controlling the circulation
pump for the hot water loop. The relay turns ON and OFF in
response to the “W” input from the wall thermostat or zone
control.
The field installed boiler pump MUST NOT exceed 1 h.p. For
continuous pump operation, wire the system pump to the 120V
supply. The pump should be connected at the junction box as
shown in FIG. 4-3.
TO
CIRCULATION
PUMP
120V
SUPPLY
TO
UNIT
Figure 4-3_Boiler Wiring - Circulation Pump to Junction Box