Part number 550-100-305/0916
35
AquaBalance
TM
W
ALL
M
OUNT
GAS
-
FIRED
WATER
BOILER
— C
OMBI
Boiler Manual
16
Install water piping
(continued)
This boiler is
NOT
intended for connection with a
refrigeration system.
General piping information
!DDITIONALCONTROLSIFREQUIRED
The control uses temperature sensors to provide
both high limit protection and modulating
temperature control.
The control’s high limit
function requires manual reset
. Some codes/
jurisdictions may require additional external
controls for high limit and/or low water cutoff
protection.
Additional limit controls
Following standard industry practices, if installation is to comply
with ASME requirements, an additional high temperature limit
may be needed. Consult local requirements for other codes/
standards to determine if needed.
1. Install a manual reset high temperature limit to prevent a
temperature above 200°F in system supply piping between
boiler and isolation valve. (Note that the control operating
limit function shuts the boiler down at 195°F, or lower if set
to a lower value.)
-ULTITEMPERATURESYSTEMS
— If the heating sys-
tem includes circuits that require lower temperature
water (radiant slab circuits, for example) as well as
higher temperature circuits, it is recommended to
protect low temperature circuits with limit controls
that are wired to the control external limit circuit
terminals.
,OWTEMPERATURESYSTEMS
— If using temper-
ature-limited materials (such as PEX tubing) in
system piping, it is recommended to protect the
system with limit controls that are wired to the
controls external limit circuit.
2. See instructions beginning on page 46, for wiring information.
3. If using a manual reset limit control or wiring in the manual
reset circuit, set boiler control limit at least 20°F less than the
external manual reset limit (i.e., set control no higher than
180°F for a 200°F external limit, for example).
"ACKmOWPREVENTER
Use backflow preventer in the cold water supply piping if
required by local codes.
System/zone pipe sizing
"ASEBOARDCONVECTORSORCASTIRONRADIATORS/.,9
For residential space heating applications (other than radiant
heating or unit heaters) ONLY, you can use the sizing sugges-
tions in Figure 44.
Studies have indicated that dangerous bacteria
can form in potable water distribution systems
if certain minimum water temperatures are not
maintained. Contact local health department for
more information.
Figure 44
3UGGESTEDPIPESIZINGFORSYSTEMHEADERS
ANDZONEPIPING2%3)$%.4)!,WITH
BASEBOARDCONVECTORSORCASTIRONRADIATORS
/.,9&TEMPERATURERISE
System water piping methods
0RIMARYSECONDARYPIPINGTOBOILER
Using primary/secondary piping will provide the most efficient
and reliable operation of the boiler and the heating system.
-ODEL
3YSTEMHEADER
7-"#
vORLARGER
2ECOMMENDATIONSAREBASEDONA&TEMPERATUREDROP
THROUGHTHESYSTEM
3UGGESTEDMAXIMUMLOADPERZONE
#OPPERPIPEAND
BASEBOARDSIZE
-AXIMUMRECOMMENDED
FEETOFBASEBOARD
Ðv
67
v
3IZEZONECIRCULATORSTOHANDLETHEREQUIREDmOWANDHEAD
LOSSFOREACHZONE
to entering the boiler. Plugging of the domestic system by
scaling or accumulation of dirt is not the responsibility of
Weil-McLain, and suitable steps must be taken to avoid it.
s #LEANING REFER TO THE INSTALLATION MANUAL MAINTENANCE
section for the proper cleaning procedure for the plate
DHW heat exchanger, and the required cleaning frequency.
