Weil-McLain Evergreen EVG 220 Manual page 46

®
gas
System piping -
See Advanced Manual for Multiple Boiler Systems
Radiant Heating — Circulator zoning –
primary/secondary (Shown with optional DHW piping)
See Figure 55.
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1. The Evergreen boiler is ideal for use in radiant heating. The unique
heat exchanger design allows it to work well even in condensing
mode. There is no need to regulate boiler return water temperature
in radiant heating applications.
2. Apply this configuration for typical radiant heating applications.
3. Size the system piping and circulators to provide the flow and pres-
sure drop needed.
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 47, page 39 on all boiler loop piping (connecting
boiler to and from the primary/secondary connection).
Use only primary/secondary piping as shown.
Failure to follow these guidelines could result in system
problems.
High limit in system piping
1. Add the recommended high limit control (Figure 55, item 22) to help
ensure supply water temperature will not exceed the maximum allow-
able for the radiant system.
2. Wire the limit control to either the manual reset or automatic reset
external limit circuit of the Control.
Expansion Tank required
1.
Provide a system expansion tank following the guidelines on page 42.
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 129 to ensure compliance with the 2007 Energy Act. See
Advanced Manual to configure Boiler Pump to run during DHW
demands and change TARGET MOD SENSOR to System Supply.
3. DHW Priority operation— Using Priority 1 for DHW (default) will
turn off lower priorities during DHW calls. The MAX ON TIME
setting can be adjusted to limit how long this occurs. Use Priority
2 or 3 for DHW if DHW priority is not desired.
Overriding the Outdoor Reset function by setting control
to DHW mode when system is intended for space heat-
ing may violate Section 303 of the 2007 Energy Act. See
page 129 for compliance information and exemptions.
1
Evergreen boiler
2
Indirect water heater, if used
3
Relief valve, supplied with
boiler, field piped — MUST
be piped to boiler supply
connection — see page 41 for
information.
4
Relief valve piping to drain —
see page 41.
5
DHW circulator.
6
Isolation valves.
8
Supplementary expansion tank,
diaphragm type, if used.
– 46 –
-
fired water boiler
Single Boiler Systems
Legend — Figure 55
9
Air separator.
10 Flow/check valves or spring check.
11 Purge/drain valves (one drain
valve is supplied loose with the
boiler).
12 Boiler circulator.
14
Primary/secondary connection (tees
no more than 12 inches apart)
20 Make-up water supply.
22 High limit temperature control,
when required by local code or
for a radiant system.
23 Backflow preventer, if used.
— 220/299/300/399 Boiler Manual
Figure 55
Typical radiant heating system piping —
circulator zoning
Controlling the circulators
1. The control can control up to four circulators (boiler circu-
lator and three others). Refer to Field wiring, beginning on
page 52, for instructions on wiring to circulators.
2. The factory default settings are: all three inputs are set up
for Space Heating (
respective circulator output. For DHW Priority applications,
wire aquastat to Input 1 and assign to Priority 1. See Field wiring
instructions, beginning on page 52, for details.
3. For more than 3-zones, use Weil-McLain WMCR zone Circ
controller.
24 Zone circulators.
25 Pressure reducing valve, if used.
26
Pressure/temperature gauge,
supplied with boiler, field
piped.
27 Quick-fill valve, if used.
28 Heating circuits.
29 Additional heating circuits, if
any.
30 Mixing device, if any
31 System supply and return sen-
sors: Strap system sensors to
(continued)
MINIMUM
Boiler loop pipe size
Evergreen 220
Evergreen 299/300, 399
See CAUTION at left.
Priority 2)
. Each input correlates to its
lines as shown, at least 6 pipe
diameters (but no more than
3 feet) from boiler connection
tees.
32 Low Water Cut-off
= Items supplied with boiler
— all other items supplied by
installer.
Part number 550-100-131/0120
1¼"
1½"