Direct Connect System Piping
(continued)
Figure 51
ECO 70/110/155
Zone valve zoning direct
connection (system circulator provides fl ow for
system)
Part number 550-142-190/1218
46
LEGEND for
Figure 51
Note:
This is a common legend for all piping diagrams.
Not all items listed appear in every fi gure.
1 ECO wall mount boiler
2 Indirect Water Heater, if used
3 Relief valve, supplied with boiler, fi eld piped — MUST
be piped to boiler supply connection — see page 14 for
information
4 Relief valve piping to drain — see page 45
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
determine if backfl ow preventers, pressure reducing
valves, and fi ll 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, fi eld
piped
27 Heating circuits
28 Additional heating circuits, if any
29 Boiler circulator, if any
30 Mixing valve, if any
31 Low Water Cut-Off (If used)
ZONE VALVE zoning –
direct connection
(Shown with optional DHW piping)
See Figure 51 .
1. This
confi guration is for zone valve systems that qualify to
use direct connection piping based on the criteria on page 43
only. If system does not qualify, pipe using primary/secondary
piping. See pages 48 - 53 for piping suggestions and guidelines.
2. Systems zoned with zone valves MUST use a by-pass pressure
regulator (Taco 3196 shown).
3. Install a system circulator (supplied by installer) capable of
delivering the proper fl ow and head as shown.
Expansion Tank required
1. Provide a system expansion tank following the guidelines on
page 43 or page 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 63 to ensure compliance with the 2007 Energy Act.
3. DHW Priority operation—The
ECO
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. See page 74 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 con-
necting space heating zones to inputs and outputs
intended for DHW applications may violate
Sec-
tion 303 of the 2007 Energy Act.
See page 127 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 fi eld wiring,
beginning on page 60 , for instructions on wiring to zone
valves.
2. The boiler and zone valves can also be operated by a
Weil-McLain WMZV zone controller.
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.
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