Weil-McLain WM97+100 Manual page 52

WM97+ Series 2
System piping
CIRCULATOR zoning — primary/secondary
The boiler primary/secondary by-pass valve MUST be open to
prevent excessive head caused by running the boiler circulator
and zone circulators in series.
the boiler internal primary/secondary by-pass valve.
1.
2. Install a separate circulator for each zone. The boiler circulator
be used for a zone. It must remain in the boiler, as installed at the factory.
1. Provide a system expansion tank following the guidelines on page 46.
2. DO NOT use a closed-type tank if connecting to a water heater that
is equipped with an automatic air vent.
1. DHW or Aqua Logic (CWH) direct connection — Pipe from the
boiler's bottom connections to water heater boiler connections as
shown. See the Aqua Logic (CWH) manual for Aqua Logic (CWH)
piping instructions.
2. DHW tank as a zone — A DHW tank can be piped as a zone (as in
Figure 63, page 56) if a DHW tank or Aqua Logic (CWH) is
nected to the boiler. Wire the DHW circulator to boiler Zone 1. Set the
boiler circulator to ON in the DHW Settings menu.
3. Priority option — By default, the WM97+ control turns off space heat-
ing to its Zone 2 and Zone 3 outputs during domestic water heating on
Zone 1. 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.
4. If connecting a water heater, terminate the bottom connections
as shown in the inset on Figure 59.
1. The WM97+ control operates up to three zones (DHW or Aqua Logic
(CWH) plus two space heating, or three space heating). Refer to Field
wiring, beginning on page 64, for instructions on wiring to circulators.
2. For more than three zones, use a Weil-McLain WMCR zone controller.
See suggested wiring in this manual.
WM97+155 boiler :
Indirect water heater, when
used (for Aqua Logic (CWH)
installations, refer to the
Weil-McLain Aqua Logic
(CWH) manual).
Relief valve, supplied with
boiler, field piped — MUST
be piped to boiler supply
connection — see page 14 for
information.
Relief valve piping to drain —
see page 42.
DHW circulator.
– 52 –
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GAS FIRED WATER BOILER
(continued)
con-
Isolation valves.
System expansion tank, dia-
phragm type, when used.
Air separator.
Flow/check valves.
Purge/drain valves (one drain
valve is supplied loose with
the boiler).
Boiler circulator, with inte-
gral flow/check valve, factory
installed in boiler.
Primary/secondary by-
pass valve — see page 44 for
— Boiler Manual
DHW refers to an indirect-fired domestic
hot water storage tank. CWH refers to a
Weil-McLain Aqua Logic Water Heater.
optional DHW piping
information — OPEN: Boiler
connected as primary/sec-
ondary.
Make-up water supply.
Backflow preventer, when
used.
Zone circulators.
Pressure reducing valve, when
used.
Quick-fill valve, when used.
DHW boiler water supply
connection, when used — see
page 14 for information.
Circulator zoning plus
DHW boiler water return
connection, when used — see
page 14 for information.
Pressure/temperature
gauge, supplied with boiler,
field piped.
Heating circuits.
Additional heating circuits, if
any.
= Items supplied with boiler
— all other items supplied by
installer.
Part number 550-142-204/0117