Weil-McLain 4 Series Manual page 53

®
Series 4
Install water piping — advanced
Example system with DHW as a zone,
zoning with circulators
1. Connect boiler to system as shown in Figure 49 when circula-
tor zoning. The boiler circulator cannot be used for a zone.
It must supply only the boiler loop. Also see the information
on page 10 for suggested piping and sizing.
Use the
Figure 49 on all boiler loop piping (connecting
boiler to and from the primary/secondary connec-
tion, item 21).
could result in system problems.
2. Install a separate circulator for each zone.
3. DO NOT use a closed-type tank with a AQUA PLUS water
heater in the system. The automatic air vent required on the
water heater will deplete air in the system, causing the expan-
sion tank to waterlog. Use only a diaphragm- or bladder-type
tank, suitable for automatic air vent applications.
4. In this example, the AQUA PLUS 60 DHW tank is piped as
a zone in the system, with piping connections to the tank in
accordance with the AQUA PLUS manual.
5. Wiring to the U-Control
a. Priority 1 = AQUA PLUS 60 (zone 1): wire AQUA PLUS
60 aquastat terminals to U-Control P11, pins 4 and 5.
Wire DHW circulator, A, to U-Control P2, terminals 1,
4 and 7 (H, N, G).
b. Wire zone pumps B and C to a two-zone circulator relay.
c. Priority 2 = fi nned-tube baseboard (zones 2 and 3): wire
circulator relay end switch 1 to U-Control P15, pins 1
and 2.
6. Make sure to set Priority 1 to DHW system, not DHW direct.
Overriding the Outdoor Reset function by setting control
to DHW mode when system is intended for space heat-
ing may violate Section 303 of the 2007 Energy Act. See
page 137 for compliance information and exemptions.
7. Controlling the system circulator and boiler circulator
a. You will have to set up the U-Control to operate both the
boiler circulator and the DHW circulator during DHW
operation. Read the instructions on U-Control operation
and setup, beginning on page 32 .
1 Ultra boiler
2 Indirect water heater (DHW), if used
3 Boiler relief valve (see page 9 for piping details)
4 Relief valve discharge piping (see page 9 for details)
6 Isolation valves
8 Diaphragm (or bladder) type expansion tank (see page 56 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 550-100-400/0119
gas-fired water boiler — Boiler Manual
pipe size shown in
Failure to follow these guidelines
Legend — Figure 49
(continued)
Figure 49
Boiler loop pipe size
Ultra-80, 105
1"
Ultra-155, 230
1¼"
Ultra-299/310,
1½"
399
See CAUTION at left.
10 Flow/check valves
11 Purge/drain valves
12 Boiler circulator
20 Make-up water supply
21 Primary/secondary connection (tees no more than 12 inches 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 Temperature/Pressure gauge
Items supplied with boiler
Items supplied by others
53