LAARS Mighty Max HH (Sizes 320M - 400M) - Installation, Operation and Maintenance Instructions - Manual (Page 5)

Mighty Max Hydronic Boiler Page 5
boiler when this mixture is used, increase the water
flow recommendation by 15%. Increase the head loss
requirement by 20%. Note: If your application does
not require the full freeze protection of a 50%/50%
mixture, it is beneficial to use a maximum 30% glycol
solution. This mixture will protect the boiler to
temperatures of about 5°F (-15°C), and will serve as
burst protection for boilers that are not in use.
Power outage, interruption of gas 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.
NOTE: 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 particular conditions.
2.5 Installation of Indoor Boilers
2.5.1 Combustion Air Supply and
Ventilation
There are a variety of options available to the
installer when it comes to venting and combustion air;
venting can be vertical or horizontal, it can originate at
the top of the boiler or the back, and combustion air
can be obtained from the room where the boiler is
installed or ducted directly to the boiler from outdoors.
See Sections 2.10 through 2.13 for details.
Mighty Max units are Category I fan-assisted
when vented vertically and adhering to all applicable
codes. Mighty Max units are not allowed to be vented
into a common horizontal vent system, unless a
properly-sized vent fan is used, and the common vent
system is properly designed by the vent fan
manufacturer or a qualified engineer.
When common venting Mighty Max fan-assisted
heaters with other appliances through one shared
vertical duct called a “common vent”, special care
must be taken by the installer to ensure safe operation.
In the event that the common vent is blocked, it is
possible, especially for fan-assisted devices, to vent
backwards through non-operating appliances sharing
the vent, allowing combustion products to infiltrate
occupied spaces. If the appliances are allowed to
operate in this condition, serious injury or death may
occur.
WARNING
Operation of appliances with a blocked common
vent may lead to serious injury or death. Safety
devices must be implemented to prevent blocked
common vent operation. If safe operation of all
appliances connected to a common vent cannot be
assured, including prevention of spillage of flue
gasses into living spaces, common venting should
not be applied, and appliances should each be
vented separately.
It is for this reason that, in addition to following
proper vent sizing, construction and safety
requirements from the National Fuel Gas Code, ANSI
Z223.1 or in Canada, from CSA B149.1 as well as all
applicable local codes, it is required that installers
provide some means to prevent operation with a
blocked common vent. It is suggested that a blocked
vent safety system be employed such that if the switch
from one appliance trips due to excessive stack spill or
backpressure indicating a blocked vent condition, that
all appliances attached to the vent be locked out and
prevented from operating. (Note that the Mighty Max
unit is equipped with a blocked vent safety (pressure)
switch, as shipped. As an additional precaution, it is
recommended that a Carbon Monoxide (CO) alarm be
installed in all enclosed spaces containing combustion
appliances. If assistance is required in determining
how a blocked vent safety system should be connected
to a LAARS product, please call Applications
Engineering at (603) 335-6300.
Refer to the installation and operating
instructions on all appliances to be common vented for
instructions, warnings, restrictions and safety
requirements. If safe operation of all appliances
connected to a common vent cannot be assured,
including prevention of spillage of flue gasses into
living spaces, common venting should not be applied,
and appliances should each be vented separately.
2.5.2 Removal of Existing Boiler
At the time of removal of an existing boiler, the
following steps shall be followed with each appliance
remaining connected to the common venting system
placed in operation, while the other appliances
remaining connected to the common venting system
are not in operation.
1.
Seal any unused openings in the common
venting system.
2. Visually inspect the venting system for proper
size and horizontal pitch and determine there is
no blockage or restriction, leakage, corrosion and
other deficiencies which could cause an unsafe
condition.
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