Specifications

Part number 550-100-090/0809
13
g a s -f i r e d w a t e r b o i l e r — Boiler Manual
BASIC INSTALLATION
Legend — Figure 6
1 Ultra boiler
2 Indirect water heater (DHW), if used (see page 52)
3 Boiler relief valve (see page 9 for piping details)
4 Relief valve discharge piping (see page 9 for details)
5 DHW circulator (see page 52 for suggested sizing)
6 Isolation valves
7 System circulator (see information above for wiring)
8 Diaphragm (or bladder) type expansion tank (see page 52 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
12 Boiler circulator
14 Zone circulators, typical
20 Make-up water supply
21 Primary/secondary connection (tees no more than 12 inches apart)
23 DHW connections — see water heater manual for piping
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.
Items supplied with boiler
Items supplied by others
Install water piping — typical systems (continued)
Figure 6 Circulator zoning plus optional DHW piping
Zoning with circulators
Connect boiler to system as shown in 1. Figure 6 when circulator
zoning. The boiler circulator cannot be used for a zone. It must
supply only the boiler loop. Also see the information on page 14
and page 15 for suggested piping and sizing.
Use at least the MINIMUM pipe size shown in Figure 6
on all boiler loop piping (connecting boiler to and from
the primary/secondary connection, item 21). Use only
primary/secondary piping as shown.
Failure to fol-
low these guidelines could result in system problems.
Install a separate circulator for each zone.2.
When using a closed-type expansion tank, connect the expansion 3.
tank and make-up water piping as shown in Figure 4, page 11. (DO
NOT use a closed-type tank with a PLUS water heater.)
Connect DHW (domestic hot water) piping to indirect storage 4.
water heater as shown.
By default, the U-Control Module turns off space heating
during DHW heating (if DHW input is priority 1). The
boiler circulator will turn off, preventing hot water from
circulating to the system (optional timeout setting can
be used to override). The flow/check valve shown on the
boiler outlet piping prevents gravity circulation in the
boiler loop during DHW heating.
Controlling the circulators5.
The U-Control can control up to three circulators (boiler cir-a.
culator and two others). Refer to Field wiring, beginning on
page 26, for instructions on wiring to circulators.
The factory default settings are: DHW circulator as Circula-b.
tor 1, boiler circulator as Circulator 2. See Field wiring instruc-
tions, beginning on page 26, for details.
The zone circulators in c. Figure 6 must be controlled by circulator
relays activated by the zone thermostats or zone controller.
Other piping alternatives
See page 14 and page 15 and ADVANCED INSTALLATION section for additional piping suggestions.
MINIMUM
Boiler loop pipe size
Ultra-80, 105
Ultra-155, 230
Ultra-299, 399
1”
1¼”
1½”
See CAUTION at left.