LAARS MAX 165 (DV) - Installation, Operation and Maintenance Instructions - Manual (Page 9)

MAX Oil-Fired Boiler Page 9
8. As the balanced flue vent system operates under
a slight positive pressure it is essential to seal all
flue joints to prevent leakage of flue gases into
the building. Vent exhaust piping must be
certified pressure venting.
9. Vent terminal should be well away from
shrubbery or other obstructions that would
prevent free air flow to and from vent terminal.
Do not terminate vent under decks, stairways, or
car ports. When ever possible, locations under
windows should be avoided.
10. Vent termination should not be mounted
directly above or within 3' horizontally from
an oil tank vent.
3J. Installation of Balanced Flue System
1. Having decided the location for the terminal, cut
a hole in wall 7.5" high x 10.5" wide (191 x
267mm).
2. Insert terminal through the hole from outside and
screw to wall at the fixing flange, after applying a
bead of silicone sealant on the back face of the
flange.
3. Fit the 5 in. flexible pipe between end of
terminal and boiler flue outlet, cutting pipe to
suit installation. Secure both ends of pipe with
clamps and seal with silicone sealant to prevent
any flue gas leakage.
The pipe should rise from the boiler to terminal
and be supported at regular intervals dependent upon
length of pipe used.
Terminal must be installed pitching down to outside
¼" per foot to prevent rain entering vent piping.
Notes: (a) The “Univent” terminal is certified
for use with zero clearance from combustible
materials. The connection between the flue pipe and
the balanced flue terminal must be provided with a 6"
(152mm) clearance from combustibles or any reduced
clearance acceptable to NFPA 31. P/N 70-330
(included with all direct vent kits) may be installed on
the balanced flue terminal to reduce the required
clearance to 2" in accordance with NFPA 31.
(b) The terminal is packed with insulation and is
also air cooled thus making it suitable for installation
through combustible walls.
4. Fit the 4 inch pipe adapter to the underside of
terminal and connect the 4 inch flexible pipe
between adapter and air intake ring on burner
after first removing the black shroud. Cut the
pipe to suit installation and securely fasten to
burner and terminal with three fixing screws.
Support pipe at regular intervals dependent upon
length.
5. Finally, seal all around terminal on inside of wall
with silicone sealant.
Note: “Univent” suitable for wall thickness up
to 10" (229mm).
3K. Boiler Piping
The supply manifold (control center) provided
with the boiler comes equipped with an air eliminator
provided through an automatic float vent. This will
provide system air elimination. Unit may be piped into
a non diaphragm expansion tank utilizing this
connection.
The pressure relief valve should be piped to a
safe place of discharge.
The piping and related connections should
follow good practice using approved joint sealants and
conform with all state and local codes. When the
boiler is connected to applications where standby
temperatures may drop below 60°F (16°C) or to a
large volume of water (e.g. radiant floors) then an anti-
condensing means must be provided. This may be
accomplished utilizing a by-pass loop (
see Figure 12 )
or optional thermostatic union ( see Figure 13 ) p/n
2400-030.
Note: This is a low mass boiler. Follow
suggested piping diagrams to minimize the chance of
short-cycling.
3L. Freeze Protection
Proper precautions for freeze protection are
recommended for boiler installations in areas where
the danger of freezing exists.
Power outage, interruption of oil supply, failure
of system components, activation of safety devices,
etc., may prevent a boiler from firing. Any time a
boiler is subjected to freezing conditions, and the
boiler is not able to fire, and/or the water is not
able to circulate, there is a risk of freezing in the
boiler or in the pipes in the system. When water
freezes, it expands. This can result in bursting of
pipes in the system, or damage to the boiler, which
could result in leaking or flooding conditions.
Freeze protection additives may be used. Do not
use automotive anti-freeze. Maintaining a mixture of
minimum 65% water and maximum 35% properly
inhibited HVAC glycol, which contains an anti-
foamant, is the preferred method of freeze protection
for Max boilers. Percentage of glycol used in the
Max boiler must not exceed 35%. Typically, this
mixture will serve as freeze protection for
temperatures down to approximately 0°F (-18°C), and
will serve as burst protection for temperatures down to
approximately –35°F (-30°C).
IMPORTANT NOTES: Different glycol
products may provide varying degrees of protection.
Glycol products must be maintained properly in a
heating system, or they may become ineffective.
Consult the glycol specifications, or the glycol
manufacturer, for information about specific products,
maintenance of solutions, and set up according to your