Install Instructions

Part number 550-100-131/0715
– 46 –
™
GAS-FIRED WATER BOILER — Boiler Manual
&IGURE Chilled water system plus optional DHW
piping
WATER CHILLER systems — ZONE VALVES
primary/secondary
See Figure 54.
1. The chiller must be piped in parallel with the boiler.
2. Use appropriate valves to prevent chilled medium from entering boiler.
3. Circulator zoning option — The space heating system can be zoned with
circulators if a separate circulator is supplied for the chilled water loop.
Install a separate circulator for each zone.
4. The flow/check valve shown on the boiler outlet piping prevents gravity
circulation in the boiler loop during DHW heating.
Use at least the MINIMUM pipe size shown in Figure 44, page 37 on
all boiler loop piping (connecting boiler to and from the prima-
ry/secondary connection). Use only primary/secondary piping as
shown. Failure to follow these guidelines could result in system
problems.
If antifreeze is used in the system, consider the effects of antifreeze
on circulator sizing and DHW performance. Some local codes
may require double-wall DHW heat exchanger design. Use only
the antifreeze listed by Weil-McLain for use with this boiler. See
page 84 for details.
Chilled medium, if used, is piped in parallel with heating boiler
as shown in Figure 54. Use appropriate valves to prevent chilled
medium from entering boiler. If boiler is connected to heating
coils located in air handling units where they can be exposed to
refrigerated air, use flow control valves or other automatic means
to prevent gravity circulation during cooling cycle.
Expansion Tank required
1.
Provide a system expansion tank following the guidelines on page 40.
2. DO NOT use a closed-type tank if connecting to a water heater that is
equipped with an automatic vent.
Domestic Hot Water (DHW) tank, if used
1. DHW direct connection—Pipe from the near-boiler piping to the DHW
tank’s boiler connections as shown.
2. DHW as zone—A DHW tank can be connected as a zone if a DHW tank
is NOT already connected to the boiler. See notices on page 127 to ensure
compliance with the 2007 Energy Act.
3. DHW Priority operation—The Control turns off space heating to the
HEAT zones during domestic water heating calls on the DHW input. The
MAX ON TIME setting can be adjusted to limit how long this occurs. Set
the MAX ON TIME to “0” to disable domestic priority.
Overriding the Outdoor Reset function by setting control to
DHW mode when system is intended for space heating may
violate Section 303 of the 2007 Energy Act. See page 127 for
compliance information and exemptions.
Controlling the circulators
1. The control can control up to four circulators (boiler circulator and three
others). Refer to Field wiring, beginning on page 50, for instructions on
wiring to circulators.
,EGEND&IGURE
 Evergreen boiler
 Indirect water heater, if used

Relief valve, supplied with
boiler, field piped — MUST
be piped to boiler supply
connection — see page 39 for
information.
 Relief valve piping to drain —
see page 39.
 DHW circulator.
 Isolation valves.
 System circulator.
 Air separator.
 Flow/check valves or spring check.
 Purge/drain valves (one drain
valve is supplied loose with the
boiler).
 Boiler circulator.
 Zone valves.
14 Primary/secondary connection
(tees no more than 12 inches apart)
 Supplementary expansion tank,
closed type, REQUIRED for
chiller systems (some chiller
systems may use a diaphragm
type expansion tank).
 Water chiller.
 Check valve.
 Y-strainer.
 Balancing valve.
 Make-up water supply.
 By-pass pressure regulator,
RECOMMENDED for zone
valve systems unless other
provision is made.
 Backflow preventer, if used.
 Pressure reducing valve, if used.

Pressure/temperature gauge,
supplied with boiler, field piped.
 Quick-fill valve, if used.
 Heating circuits.
 Additional heating circuits, if
any.
System supply and return
sensors: Strap system sen-
sors to lines as shown, at
least 6 pipe diameters (but
no more than 3 feet) from
boiler connection tees.
 = Items supplied with boiler
— all other items supplied by
installer.
Use isolation relays if connected 3-wire zone valve end
switches to the Heat inputs.
Connect zone valve end switches to Priority 2 input.
Connect system circulator to CIRC 2 output.
2. The factory default settings are: all three inputs are setup for
Space Heating (Priority 2). Each input correlates to its re-
spective circulator output. For DHW applications, set Input
1 to Priority 1. See Field wiring instructions, beginning on
page 50, for details.
3. For more than 3-zones, use Weil-McLain WMZV zone valve
controller.
System piping - Single Boiler Systems (continued)
See Advanced Manual for Multiple Boiler Systems
-).)-5-
Boiler loop pipe size
Evergreen 220
Evergreen 299/300, 399
1¼”
1½”
See CAUTION at left.