Weil-McLain Gold CGi Series 2 User Manual page 22

GOLD
4c
Piping multiple
zones
Zoning with
circulators, return
temp over 130 °F
Zoning with zone
valves, return temp
over 130 °F
Piping for radiant
heating systems or
converted gravity
systems
22
CGi Series 2 Gas-Fired Water Boiler
Water piping —
Follow instructions on pages 20 and 21 to install near-boiler or single-zone piping. (Also
refer to
Piping for radiant heating systems or converted gravity systems
applicable.)
See or
Figure 18 Figure 19
1. Size each circulator to individual circuit requirements.
2. Do not install circulator on boiler (except for primary/secondary piping).
3. Install isolation (balancing) valves to adjust flow to distribute heat to all zones.
4. Install and wire a separate relay for each zone circulator.
1. Install isolation (balancing) valves to adjust flow to distribute heat to all zones.
2. Provide a separate 24-volt transformer to power the zone valves. Size the transformer to
handle the total rated load of all connected zone valves.
Converted gravity (or steam) systems
Whenever possible, use the primary/secondary piping shown in
This piping design allows changing boiler flow rate without affecting primary circuit flow
rate.
If cannot be used, use the boiler-bypass piping shown in
Figures 20 or 21
on page 27. You can also use the piping shown in
23
the reduced flow rate in the heating system will not cause heat distribution problems.
Failure to prevent low return water temperature to the boiler could cause corrosion of the
boiler sections or burners, resulting in severe personal injury, death or substantial property
damage.
Radiant heating systems
Preferably, use primary/secondary piping, as shown in
Alternatively, use the method of either
(system-bypass), because this method does not control radiant system
piping of Figure 24
supply temperature.
If radiant system tubing has no oxygen barrier, a
Radiant heating system piping should include a means of regulating the boiler return water
temperature and the system supply temperature (such as provided by an injection pumping
control). Boiler return water temperature will be adequately controlled using the methods
shown in this manual provided the system supply temperature is relatively constant.
apply the methods in this manual if the system is equipped with an
Do not
. Instead, provide controls and piping which can regulate the boiler return water
control
temperature at no less than 130 °F regardless of system supply temperature. Contact your
Weil-McLain representative for suggested piping and control methods. Failure to prevent
cold return water temperature to the boiler could cause corrosion damage to the sections or
burners, resulting in possible severe personal injury, death or substantial property damage.
multiple zones
to complete installation.
Figure 24
Figure 22 or Figure 23
heat exchanger
, below, if
on page 25.
Figures 20 or 21
Figure 22 or Figure
on page 29 (system-bypass), if
on page 25.
Figures 20 or 21
on page 27.
Do not use the
must be used.
outdoor reset
Part Number 550-110-710/0200