Install Instructions
&IGURE Zone valve zoning — primary/secondary
connection — a system circulator is required
ZONE VALVE zoning – primary/secondary
(Shown with optional DHW piping)
See Figure 50.
1. This configuration is for zone valve systems using a boiler loop
connected as a secondary circuit off of a primary system loop.
Systems whose flow characteristics do not comply with those listed
in Figure 41, page 37 must pipe the boiler loop as a secondary
circuit as show.
2. Systems zoned with zone valves MUST use a by-pass pressure
regulator.
3. Install a system circulator (supplied by installer) capable of deliver-
ing the proper flow and head as shown.
Expansion Tank required
1. Provide a system expansion tank following the guidelines on
pages 43 or 44.
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. To provide DHW
priority operation, use a zone controller. See notices on page 59
to ensure compliance with the 2007 Energy Act.
3. DHW Priority operation—The ECO control turns off space heat-
ing 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. See page 70 for setting instructions.
4. If NOT connecting a water heater, do not use the DHW input or
DHW Circulator output on the ECO control.
Overriding the Outdoor Reset function by connecting
space heating zones to inputs and outputs intended for
DHW applications may violate Section 303 of the 2007
Energy Act. See page 119 for compliance information
and exemptions.
Controlling the Zones
1. The ECO control can be used to control space heating only,
domestic water heating only, or both. Refer to field wiring,
beginning on page 56, for instructions on wiring to zone valves.
2. The boiler and zone valves can also be operated by a
Weil-McLain WMZV zone controller.
Primary/Secondary System piping (continued)
,%'%.$FOR&IGURE.
.OTEThis is a common legend for all piping diagrams, Not
all items listed appear in every figure.
1 ECO wall mount boiler
2 Indirect Water Heater, if used
3 Relief valve, supplied with boiler, field piped — MUST
be piped to boiler supply connection — see page 12 for
information
4 Relief valve piping to drain — see page 46
5 DHW circulator
6 Isolation valves
7 System circulator
8 Expansion tank, diaphragm type, if used
9 Air separator
10 Flow/check valves
11 Purge/drain valves
(one drain valve shipped loose with boiler)
12 Auto air vent
13 Zone valves
14 Primary/secondary connection (tees no more than 12
inches apart)
15 Expansion tank, closed type, if used (some chiller
systems may use a diaphragm-type expansion tank)
16 Water chiller
17 Check valve
18 Y-strainer
19 Balancing valve
20 Make-up water supply – Use applicable codes to deter-
mine if backflow preventers, pressure reducing valves,
and fill valves may be required
21 By-pass pressure regulator, REQUIRED for zone valve
systems unless other provision is made
22 High limit temperature control
23 DHW tank boiler water supply connection, when used
24 Zone circulator
25 DHW tank boiler water return connection, when used
26 Pressure/temperature gauge, supplied with boiler, field
piped
27 Heating circuits
28 Additional heating circuits, if any
29 Boiler circulator, if any
30 Mixing valve, if any
Connect zone valve end switches to HEAT
input. Connect system circulator to HEAT
Circ. output.
Use isolation relays if connecting 3-wire zone
valve end switches to the HEAT input.
Part number 550-142-122/0513
47
TM
GAS-FIRED WATER BOILER — Boiler Manual