Installation Guide

Part number 550-100-066/0608
g a s -f i r e d w at e r b o i l e r — Boiler Manual
18
Legend — Figure 16
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 (tees no more than 12 inches apart)
23 DHW secondary connector piping — 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.
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 — alternate
High-flow-rate/high-head-loss DHW circuits
For applications requiring DHW circuit ow rates higher than al-1.
lowable for the boiler, or for high pressure-drop coil-type DHW
tanks, connect the piping as in Figure 16. The DHW water only
ows through the secondary circuit connector piping. NOTE: Make
sure to size the connector piping (Figure 16, item 23) to handle the
total ow it must handle.
Connect boiler to system as shown in 2. Figure 16 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 3.
tank and make-up water piping as shown in Figure 14, page 16.
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 ow/check valve shown on the
boiler outlet piping prevents gravity circulation in the
boiler loop during DHW heating.
Controlling the system circulator and boiler circulator5.
You will have to set up the U-Control to operate both the boiler a.
circulator and the DHW circulator during DHW operation.
The system circulator should be off during DHW heating. Read
the instructions on U-Control operation and setup, beginning
on page 59.