Weil-McLain WM97+100 Manual page 54

WM97+ Series 2
System piping
RADIANT HEATING — CIRCULATOR zoning
1. The WM97+ 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 pressure
drop needed.
1. Add the recommended high limit control (Figure 61, item 22) to help
ensure supply water temperature will not exceed the maximum allowable
for the radiant system.
2. Wire the limit control to either the manual reset or automatic reset external
limit circuit of the WM97+ control.
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 Fig-
ure 63, page 56) if a DHW tank or Aqua Logic (CWH) is
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 heating
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 61.
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 67, 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.
– 54 –
-
GAS FIRED WATER BOILER
(continued)
connected
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
information — OPEN: Boiler
— Boiler Manual
DHW refers to an indirect-fired domestic
hot water storage tank. CWH refers to a
Weil-McLain Aqua Logic Water Heater.
system piping — circulator zoning
connected as primary/second-
ary.
Make-up water supply.
High limit temperature con-
trol.
Backflow preventer, when
used.
Zone circulators.
Pressure reducing valve, when
used.
Quick-fill valve, when used.
DHW boiler water supply
connection, when used — see
Typical radiant heating
page 14 for information.
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