Weil-McLain SlimFit 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 pre-
vents gravity circulation in the boiler loop during DHW heating.
Use at least the MINIMUM pipe size shown in Fig-
ure 12, page 15 on all boiler loop piping (connecting
boiler to and from the primary/secondary connec-
tion, item 21). Primary/secondary piping shown
ensures the boiler loop will 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 dur-
ing DHW demands and change TARGET MOD SENSOR to
System Supply.
3. Priority of DHW/Space Heating:
a. DHW Priority – DHW is priority over space heating. Use
Priority1 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; Prior-
ity 3 for DHW. The control will not run multiple priorities
simultaneously.
c. No Priorities – Space heating and DHW can occur simulta-
neously. Use only if DHW is a zone in system. Assign DHW
and Space heating to same Priority. Do not use outdoor
reset for this 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.
2. The factory default settings are: all three inputs are set up
for Space Heating (Priority 2). Each input correlates to its
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 550-100-561/0224
commercial condensing gas
(continued)
primary/secondary
See Figure 18
Legend — Figure 18
- — Boiler Manual
fired water boiler
Figure 18
Pump zoning plus optional DHW piping —
primary/secondary piping
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