User Guide

Part number 550-100-325/0718
33
AquaBalance
®
SERIES 2 WALL MOUNT GAS-FIRED WATER BOILER — Boiler Manual
16 Install water piping
Domestic Water Piping – Combi Boiler
• Thermostatic Mixing Valve - A mixing valve (for regulating
domestic heating water) must be used to regulate the water tempera-
ture leaving the plate heat exchanger. NOTE: the valve must be set to
supply a domestic water temperature of not more than 120 degrees F. It
is the responsibility of the installer to set the valve and remove the dial.
• DHW Filter- Installation of a 100 micron or lower water filter at
the entrance of the DHW connection to protect the DHW flow
switch. Failure to install the DHW water filter from dirt and debris
will cause it to malfunction.
Check Valve – A check valve must be field provided
and installed on the outlet of the mixing valve to
prevent expansion devices downstream from back
flowing when the water pressure drops during cold
water draws. Failure to prevent the backflow will cause
water to flow through the flow switch, activating it,
when the cold water draw has ended and the water
pressure increases.
• Drain and Isolation Valves- Install drain and isolation valves on the
inlet and outlet of the DHW connections so that the DHW heat
exchanger can be flushed and cleaned from possible build-up caused
by dirty or hard water, which is a maintenance requirement.
• Hard Water- To prevent the formation of scale on the inside of the
plate DHW heat exchanger and other components in the domestic
hot water system, water with hardness higher than 50 ppm Calcium
Minimum Maximum
DHW
Pressure
Rating
PSIG 4.5 130
If the boiler piping system is connected to heating coils
located in air handling units where there may be exposed
to refrigerated air circulation then it must be equipped
with flow control valves or other automatic means to
prevent gravity circulation of the boiler water during the
cooling cycle.
To pipe DHW, see Figure 43, page 34
1. Size piping for DHW inlet and outlet - 1/2” NPT on
80/120 and 3/4” NPT on the 155 boilers.
2. Additional anti-scald devices may be installed at each
hot water faucet, bath and shower outlet.
3. In hard water areas, soften cold domestic supply water
to heaters to prevent scale build-up.
4. Refer to Figure 41, below for maximum and minimum
domestic water pressure rating for our units, on the
domestic pipes (Combi only).
5. A new approved pressure relief valve that complies with
the standard for relief valves and automatic gas shut-off
devices for Hot Water Supply Systems, ANSI Z21.221
CSA4.4 is required to be installed at the supply DHW
connection (field supplied). This pressure relief valve
Figure 41 Domestic water pressure rating
Figure 42 DHW inlet has a filter screen - Port 4 - see
Figure 43, page 34
6. Combi Boiler: Domestic water inlet connection showing filter
screen to protect paddle flow switch from sand and other
debris.
Pipe in a “union” fitting below this adapter to service
this filter screen.
Use two wrenches when tightening water piping at
boiler, using one of the wrenches to prevent the boiler
interior piping from turning (wrench on both sides,
here and inside boiler). Failure to support the boiler
piping connections to prevent them from turning
could cause damage to boiler components.
should be capable of at least the Maximum input of the boiler
*
and Maximum pressure Not exceeding 130 PSIG. The pressure
relief valve’s discharge should be per instructions in the Warning
box, page 38. DO NOT place any other type valve or shut-off device
between the relief valve and the boiler. The pressure relief valve
must be manually checked once a year to verify correct operation.
*(80 KBTU/hr, 120 KBTU/hr, or 155 KBTU/hr, depending on the
boiler model).
Hot Water Can Scald!
• Consumer Product Safety Commission and some
states recommend domestic hot water tempera-
ture of 130°F or less.
• When installing an
automatic mixing valve,
selection and installation must comply with valve
manufacturer’s recommendations and instructions.
• Water heated to a temperature suitable for clothes
washing, dish washing and other sanitizing needs
will scald and cause injury.
• Children, elderly, infirm or physically handi-
capped persons are more likely to be injured by
hot water. Never leave them unattended in or near
a bathtub, shower or sink. Never allow small chil-
dren to use a hot water faucet or draw their own
bath. If anyone using hot water in the building
fits this description, or if state laws or local codes
require certain water temperatures at hot water
faucets, take special precautions:
• Install
automatic mixing valve set according to
those standards.
• Use lowest practical temperature setting.
• Check water temperature immediately after first
heating cycle and after any adjustment.