Weil-McLain Gold CGi Series 2 User Manual page 23

Boiler Manual
typical piping — multiple-zone installations
Figure 18
Zoning with circulators
— return water 130 °F or higher.
ZONE 2
ZONE 1
1
2
1
6
9
11
Cold
water
fill
12
Boiler isolation (balancing) valves
1
2 Flow/check valve
System or zone circulator
3
Zone valve
5
6 Drain valve
Relief valve
9
Automatic air vent (with diaphragm-type
10
expansion tank), or connect to tank fitting (closed-
type expansion tank).
DO NOT
For systems with possible low return-water temperature (such as converted gravity systems,
radiant heating systems and heat pump systems), refer to the special piping suggestions of
Figures 20 - 24
boiler could cause corrosion of the boiler sections, resulting in severe personal injury, death
or substantial property damage.
Part Number 550-110-710/0200
Figure 19
Zoning with zone valves
— return water 130 °F or higher.
1
2
3
1
13
6
10
Cold
water
MODEL
CGi
71020
air vent when using closed-type expansion tank. It
would allow air to leave the system, causing
waterlogging of the expansion tank.
Fill valve
11
Diaphragm-type or bladder-type expansion tank,
12
if used (For closed-type expansion tank, pipe from
top of air separator to tank fitting as in
Air separator and automatic vent, if used (Note that
13
the fill valve must always be connected to the
expansion tank, regardless of location of expansion
tank circulator or air separator.
use an automatic
, as applies. Failure to prevent sustained low return water temperature to the
ZONE 2
ZONE 1
1
6
1
9 10
11
fill
12
1
5
13
6
1
Alternate
circulator
location
MODEL
CGi
71021
.)
Figure 17
23