®
Series 3
WATER
BOILER
— Boiler Manual
Connect water piping
(continued)
Figure 11
Multiple zoning with zone valves –
Temperatures below 140 °F
Figure 10
Multiple zoning with circulators –
Temperatures below 140 °F
1. If system water temperature requirements are less
than 140 °F, such as radiant panels or converted
gravity systems, use piping as shown in Figure 10
or 11.
2. If system piping is plastic without an oxygen barrier,
a heat exchanger must be used.
3. Follow instructions on page 14 and 15 to install
near-boiler piping.
4. Zoning with circulators (Figure 10)
a. Size each circulator to individual circuit require-
ments.
b. Remove circulator (when furnished as standard equip-
ment).
c. Install balancing valves to adjust fl ow to distribute heat
to all zones.
d. Separate relay is required for each circulator.
5. Zoning with zone valves (Figure 11)
a. Install balancing valves to adjust fl ow to distribute heat
to all zones.
b. Separate transformer is required to power zone valves.
Refer to “Weil-McLain Zone Valve Wiring
Guide” for details.
6. To set the valves,
7a
and
7b
:
a. Set the valves while the system is cool, setting for the
coldest expected water temperature (usually 60 °F
since the system will often drop to room temperature
between cycles).
b. Start with valve
7a
fully closed and
7b
fully open.
c. Gradually open valve
7a
while closing
7b
until the
temperature at gauge
8
reads 130 °F when gauge
4a
reads 60 °F.
d. Note that valve
7a
regulates the amount of hot water
from the boiler supply, which mixes with return water.
Valve
7b
regulates the amount of system water fl owing
through the boiler secondary loop.
Piping MULTIPLE ZONES — System temperature below 140 °F
Zo
n
e 1
Zo
n
e 2
1
1
1
1
2
2
3
4b
4a
6
6
7b
7a
8
Max.
12”
01
3
1 Isolation
valve
2
Flow control valve
3 Circulator
4
System temperature gauges
5 Zone
valve
6 Drain
valve
7
System temperature valves. Adjust valves
8
Blend temperature gauge
9
Boiler temperature gauge (not shown)
Part number 550-142-182/1014
17