12
Copper supply and return piping must NOT be
installed directly into aluminum boiler section
castings due to galvanic corrosion between
dissimilar metals. Iron or steel bushings or
pipe nipples should be used between copper
system piping and boiler to make final connec
-
tion to boiler. Also, the use of dielectric unions
is acceptable. The packaged boiler is furnished
with iron piping where necessary for the sup-
ply and return connections.
vII - NEAR bOILER PIPING
ImPORTANT:
For piping examples using the Gas-Fired Direct Vent Modulating Hot Water Boiler, see the
Piping Appendix
in Section XVI of this manual.
CAUTION
!
When the installation of the boiler is for a new heating
system, first install all of the radiation units (panels, ra-
diators, baseboard, or tubing) and the supply and return
mains. After all heating system piping and components
have been installed, make final connection of the system
piping to the boiler.
According to code, a hot water boiler installed above ra-
diation level must be equipped with a low water cut off
device. A periodic inspection is necessary, as is flushing
of float type devices, per low water cut off manufacturers
specific instructions.
This boiler is factory equipped
with a manual reset probe-type low water cut off.
Expansion Tank & make-up water
Non-potable water only piped directly to
boiler. DO NOT connect drinking water to
heating system.
CAUTION
!
Determine required system fill pressure, system design
temperature, and system water content. Boiler contains
2.6 gallons (US). Size expansion tank accordingly. Consult
expansion tank manufacturer for proper sizing information.
Connect properly sized expansion tank (not furnished) as
shown in Figure 6 for diaphragm type expansion tank.
For diaphragm type expansion tanks, adjust the tank air
pressure to match the system fill pressure. Install air vent
(furnished) as shown for diaphragm type expansion tank
system only. Install make-up water connections as shown
GATE VALVE
REDUCED PRESSURE
BACKFLOW PREVENTER
FEED
WATER
PRESSURE
REDUCING VALVE
AIR SCOOP
DIAPHRAGM TYPE
EXPANSION TANK
SUPPLY PIPING
figure 6 - Diaphragm Type Expansion Tank Piping
PrEssurE rElIEf DEVICE
Check local codes for
maximum distance
from floor.
PrEssurE rElIEf DEVICE
flOOr
Figure 7 - Relief Valve Discharge Piping
and per local codes. If a pressure reducing valve is used,
adjust to match the system fill pressure. In connecting the
cold make-up water supply to the boiler, make sure that
clean water supply is available. When the water supply is
from a well or pump, a sand strainer should be installed
at the pump.
