Weil-McLain SVF 1500 Manual page 21

SVF
™
Series 1
Commercial Condensing Gas-Fired Water Boiler — Boiler Manual
Install water piping
Circulator zoning –
(Shown with optional DHW piping)
Th is confi guration 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 fl ow and head as shown.
2. Th e fl ow/check valve shown on the boiler outlet piping prevents
gravity circulation in the boiler loop during DHW heating.
Use at least the
page 16 on all boiler loop piping (connecting boiler to and
from the primary/secondary connection, item 21).
secondary piping shown ensures the boiler loop will
have suffi cient fl ow. For other piping methods, see guidelines
starting on page 15 .
Expansion Tank required
Provide a system expansion tank following the guidelines on
1.
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 confi gure Boiler Circulator to run during DHW de-
mands and change TARGET MOD SENSOR to System Supply.
3. System Priority choices:
a. DHW Priority – DHW is priority over space heating. Use
Priority 1 for DHW; Priorities 2 and/or 3 for space heating.
Th e 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. Th e control will not run multiple priorities simulta-
neously.
c. No Priorities – Space heating and DHW can occur simulta-
neously at same Supply Max. temperature. 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. Th e control can control up to four circulators (boiler circulator
and three others). Refer to Field wiring, beginning on page 59 , for
instructions on wiring to circulators. Th e boiler circulator cannot
be used for a zone pump.
TM
SVF
1 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]
Part number 550-100-250/0819
(continued)
primary/secondary
See Figure 18 .
pipe size shown in Figure 11,
Legend — Figure 18
Figure 18
Pump zoning plus optional DHW piping —
primary/secondary piping
2. Th e factory default sett ings 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.
10 Flow/check valves
11 Purge/drain valves
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 System supply and return immersion sensors, 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.
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