Part number 550-143-010/1021
17
GV90+
series
2
gas-fired water boiler – boiler manual
Figure 18
Zone valve zoning — GV90+3, GV90+4 or GV90+5
(DO NOT apply to GV90+6)
Figure 19
The system must meet the following requirements when applying Figure 18
Install water piping
(continued)
Legend
1 Isolation valves
2 Automatic air vent (with
diaphragm-type expan-
sion tank), or connect to
tank fitting (closed-type
expansion tank).
3 Diaphragm- or bladder-
type expansion tank, if
used. (For closed-type
expansion tank, pipe
from top of air separa-
tor to tank fitting as in
4 Zone valve
7 Hose bibb purge valve
8 Boiler pressure/tempera-
ture gauge
10 Differential pressure by-
pass valve
16 Cold water fill line — see
for
typical components
Pipe sizes (NPT), minimum
Boiler model
Mains
Circuits
GV90+3
GV90+4
1"
¾"
GV90+5
1¼"
¾"
Circuit requirements
See
Figure 19
One-pipe diverter tees systems
— The applica-
tion information on this page is based on two-
pipe baseboard systems.
To check whether the
internal circulator can provide sufficient flow
to a one-pipe diverter tee system, use the avail-
able head value given in
Boiler
model
Circulator HEAD
available to the
system
Maximum
circuit
length
L
Minimum
number
of circuits
Max load
of any
circuit
Max feet baseboard
of any circuit
(@ 600 Btuh/foot)
Summary
GV90+3
6.4 feet w.c.
@ 6.5 GPM
103 feet
2
40 MBH
67 feet
6.5 GPM total
(max 4 GPM any circuit)
20°F temperature drop
GV90+4
4.1 feet w.c.
@ 9.7 GPM
92 feet
3
33 MBH
55 feet
9.7 GPM total
(max 3.3 GPM any circuit)
20°F temperature drop
GV90+5
*
5.5 feet w.c.
@8.7 GPM
112 feet
3
53 MBH
88 feet
8.7 GPM
(max 3.5 GPM any circuit)
30°F temperature drop
GV90+6
DO NOT apply to GV90+6 — Use primary/secondary piping ONLY, as in
.
* This application may be marginal. It could cause temperature distribution problems, because the temperature drop is 30°F,
NOT 20°F. The best method is to use primary/secondary piping for the GV90+5 as in
.