Full Product Manual

4.0 Boiler Piping
- Consult heat exchanger for maximum
set point of limit.
- For wiring of the limit, reference Fig. 15,
page 29, using the external manual reset
terminals on the low voltage terminal
strip. This will provide a "hard" lockout
requiring a manual reset of the control.
4.6 Backflow Preventer
- Use a backflow preventer valve in the
make-up water supply to the unit as
required by local codes.
4.7 Boiler System Piping Applications
It is recommended on all piping applica-
tions to utilize a primary/secondary pip-
ing arrangement as a means to provide
freeze protection of the boiler, which is an
integral function of the boiler control.
Maintain the minimum boiler flow rate
shown in Graphs 1 through 6 on pages 94
through 96. For other piping arrange-
ments, contact ACV-Triangle Tube
Technical Support or consult other
approved/recognized design arrange-
ments.
On piping applications utilizing a single
zone or other recognized piping design
arrangements, it is recommended that the
installer uses flow/check valves with
weighted seats at or near the appliance to
prevent gravity circulation.
4.8 Expansion Tank and Makeup
Water
Ensure the expansion tank is properly sized for
the boiler volume (3 gallons [12 L]) and the
system volume and temperature.
Undersized expansion tanks will cause
system water to be lost through the pres-
sure relief valve and cause additional
makeup water to be added to the system.
Eventual boiler heat exchanger failure
can result due to this excessive makeup
water addition.
Refer to the expansion tank manufacturer
instructions for additional installation details.
Connect the expansion tank to an air separator
only if the air separator is located on the suc-
tion side (inlet) of the system circulator.
Always locate and install the system fill con-
nection at the same location as the expansion
tank connection to the system.
4.8.1 Diaphragm Expansion Tank
Always install an automatic air vent on the top
of the air separator to remove residual air from
the system.
4.8.2 Closed-Type Expansion Tank
It is recommended to pitch any horizontal piping
upwards toward the expansion tank 1 inch per 5
feet of piping. Use 3/4” piping for the expansion
tank to allow air within the system to rise.
DO NOT install automatic air vents on a
closed-type expansion tank system. Air
must remain in the system and be
returned to the expansion tank to pro-
vide an air cushion. An automatic air
vent would cause air to be vented from
the system resulting in a water-logged
expansion tank.
4.9 Circulator
The PRESTIGE Excellence requires an external
circulator to provide circulation through the boiler.
BEST PRACTICE
CAUTION
CAUTION
BEST PRACTICE
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