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Part number IWHA016A/1103
5
PLUS Line Instruction Manual Supplement
PLUS &
PLUS WATER HEATERS WITH GAS-FIRED WATER BOILERS
Install system water piping (space heating) (continued)
Figure 3 Circulator zoning plus optional
water heater piping
Zoning with circulators
1. Connect boiler to system as shown in Figure 3
when circulator zoning. The boiler circulator
cannot be used for a zone. It must supply only the
boiler loop.
2. Install a separate circulator for each zone.
3. When using a closed-type expansion tank, connect
the expansion tank and make-up water piping as
shown in Figure 1, page 3.
4. Connect water heater (domestic hot water) piping
to indirect storage water heater as shown.
The PhD Control Module turns off
space heating during water heater heating.
The boiler circulator will turn off,
preventing hot water from circulating to
the system. The flow/check valve shown
on the boiler outlet piping prevents
gravity circulation in the boiler loop
during water heater heating.
NOTE 1: To ensure adequate flow rate through the
boiler, use the following pipe size on all boiler
loop piping (connecting boiler to and from
the primary/secondary connection, item 21):
Ultra-80 or Ultra-105 – 1" or larger.
Ultra-155 or Ultra-230 – 1¼" or larger.
Ultra-310 – 1½" or larger.
1
Legend Figure 3
1 Ultra boiler
2 Indirect water heater (water heater), if used
3 Boiler relief valve (see boiler manual for piping details)
4 Relief valve discharge piping (see boiler manual for details)
5 Water heater circulator (see page 7 for suggested sizing)
6 Isolation valves
7 System circulator
8 Diaphragm (or bladder) type expansion tank (see page 3
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 (with weighted seats to prevent gravity
circulation)
11 Purge/drain valves
12 Boiler circulator
14 Zone circulators, typical
20 Make-up water supply
21 Primary/secondary connection
Use at least the minimum piping size above
and pipe the boiler using only primary/
secondary piping as shown. Failure to
follow these guidelines could result in
system problems.