Weil-McLain 2 Series Manual page 19

®
SlimFit Series 2
Install water piping
Circulator zoning –
(Shown with optional DHW piping)
This configuration is for circulator-zoned systems using a boiler loop
connected as a secondary circuit off of a primary system loop.
1. Install a separate circulator (supplied by installer) for each zone
capable of delivering the proper flow and head as shown.
2. The flow/check valve shown on the boiler outlet piping prevents
gravity circulation in the boiler loop during DHW heating.
Use at least the
page 15 on all boiler loop piping (connecting boiler to and
from the primary/secondary connection, item 21).
have sufficient flow. For other piping methods, see guidelines
on page 15.
Expansion Tank required
1. Provide a system expansion tank following the guidelines on
page 16.
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 Advanced
Manual to configure Boiler Circulator to run during DHW de-
mands and change TARGET MOD SENSOR to System Supply.
3. Priority of DHW/Space Heating:
a. DHW Priority – DHW is priority over space heating. Use Pri-
ority1 for DHW; Priorities 2 and/or 3 for space heating. The
control will not run multiple priorities simultaneously.
b. Space Heating Priority – Space heating is priority over DHW.
Use Priorities 1 and/or 2 for space heating; Priority 3 for DHW.
The control will not run multiple priorities simultaneously.
c. No Priorities – Space heating and DHW can occur
ously. Use only if DHW is a zone in system. Assign DHW and
Space heating to same Priority. Do not use outdoor reset for
thi
s application.
Controlling the circulators
1. The control can control up to four circulators (boiler circulator
and three others). Refer to Field wiring, beginning on page 47, for
instructions on wiring to circulators. The boiler circulator cannot
be used for a zone pump.
1 SlimFit boiler
2 Indirect water heater (DHW), if used
3 Boiler relief valve (see page 14 for piping details)
4 Relief valve discharge piping (see page 14 for details)
5 DHW circulator)
6 Isolation valves
8 Diaphragm (or bladder) type expansion tank (see page 16
for piping of closed-type expansion tank, if used)
9 Air separator [with automatic air vent only on systems using diaphragm
(or bladder) type expansion tank]
10 Flow/check valves
11 Purge/drain valves
Part number 550-100-180/0917
COMMERCIAL CONDENSING GAS
(continued)
primary/secondary
See Figure 18.
pipe size shown in Figure 12,
ensures the boiler loop will
simultane-
Legend — Figure 18
- — Boiler Manual
FIRED WATER BOILER
Pump zoning plus optional DHW piping —
primary/secondary piping
2. The factory default settings are: all three inputs are set up for
Space Heating (Priority 2). Each input correlates to its respective
circulator output. For DHW applications, assign DHW inputs to
determined Priority (1, 2 or 3). Priority 1 is defaulted to DHW
for DHW Priority applications.
3. For more than 3-zones, use Weil-McLain WMCR zone Circ
controller.
12 Boiler circulator
14 Zone pumps, typical
20 Make-up water supply
21 Primary/secondary connection (tees no more than 8 pipe diameters apart)
24 Strap system supply and return sensors to lines as shown, at least 6 pipe diameters
(but no more than 3 feet) from boiler connection tees.
26 External drain/blowdown valve, when used.
33 Strainer, recommended.
Items supplied with boiler
Items supplied by others
19