Boiler Piping
Expansion Tank and Makeup Water
Ensure the expansion tank is properly sized for
the boiler volume (3 gallons [12 L] for the
PRESTIGE Solo 60, 5 gallons [19 L] for the
PRESTIGE Solo 175/250, 7 gallons [26 L] for
PRESTIGE Solo 399) 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.
The expansion tank must be located as shown
in Fig. 7 and Fig. 8 on page 19 when using a
primary/secondary piping arrangement or as
per recognized design methods. 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.
Diaphragm Expansion Tank
Always install an automatic air vent on the top
of the air separator to remove residual air from
the system.
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.
Circulator
The PRESTIGE Solo requires an external circula-
tor to provide circulation through the boiler. The
circulator when wired directly to the PRESTIGE
Solo will allow for domestic hot water priority and
to provide circulation for the freeze protection fea-
ture of the boiler control. See Graphs 2 through 7
on pages 93 & 95 for pressure drop and minimum
flow rate through the boiler.
Sizing Primary Piping
See Fig. 9 through 13, pages 21 - 23, for rec-
ommended piping arrangements based on vari-
ous applications. Size the piping and system
components required in the space heating sys-
tem, using recognized design methods.
Domestic Hot Water System Piping
See Fig. 9 through 12, page 21-22 for recom-
mended piping to a DHW system. This recom-
mended piping configuration ensures priority is
given to the production and recovery of the DHW.
The piping for the DHW is separate from the
boiler system piping and does not require a pri-
mary / secondary piping configuration.
To wire the DHW circulator to the boiler control
module, reference Section VIII - External Wiring.
CAUTION
CAUTION
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