Installation Guide

Part number 550-100-066/0608
17
g a s -f i r e d w at e r b o i l e r — Boiler Manual
Legend — Figure 15
1 Ultra boiler
2 Indirect water heater (DHW), if used (see page 22)
3 Boiler relief valve (see page 14 for piping details)
4 Relief valve discharge piping (see page 14 for details)
5 DHW circulator (see page 22 for suggested sizing)
6 Isolation valves
7 System circulator (see information above for wiring)
8 Diaphragm (or bladder) type expansion tank (see page 22 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
13 Zone valves, typical
20 Make-up water supply
21 Primary/secondary connection
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.
25 Systems using high-head pumps may require a bypass pressure regulator
to prevent damage to control valves.
Items supplied with boiler
Items supplied by others
NOTE 1:
Use at least the following pipe sizes 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 follow these guidelines could result in system problems.
•Ultra-80orUltra-105–1”orlarger.
•Ultra-155or-230–1¼”orlarger.
•Ultra-310–1½”orlarger.
Install water piping (continued)
 Zone valve zoning plus optional DHW piping
Zoning with zone valves
Connect boiler to system as shown in 1. Figure 15 when zone valve
zoning. The primary/secondary piping shown ensures the boiler
loop will have sufficient ow. It also avoids applying the high head
of the boiler circulator to the zone valves.
When using a closed-type expansion tank, connect the expansion 2.
tank and make-up water piping as shown in Figure 14, page 16.
Connect DHW (domestic hot water) piping to indirect storage 3.
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 ow/check valve shown on the
boiler outlet piping prevents gravity circulation in the
boiler loop during DHW heating.
Controlling the circulators4.
The U-Control can control up to three circulators (boiler cir-a.
culator and two others). Refer to Field wiring, beginning on
page 54, for instructions on wiring to circulators.
The factory default settings are: DHW circulator as Circula-b.
tor 1, boiler circulator as Circulator 2 and system circulator
as Circulator 3. See Field wiring instructions, beginning on
page 54, for details.