151B0801 R5 3/28/2006
4
as to not allow twisting or sagging of the
cabinet. Position the supports so as to
not interfere with accessing the burner
and blower compartments. Suggestion;
as a measure to prevent fuel oil from
accumulating in locations other than the
fire pot, as could be the case in the event
of nozzle drip, install the furnace with an
approximate 2 degree slope from the oil
burner casing towards the fire pot.
AIR CONDITIONING
If the furnace is used in conjunction with
air conditioning, the furnace shall be
installed in parallel with or upstream from
the evaporator coil to avoid condensation
in the heat exchanger. In a parallel
installation, the dampers or air controlling
means must prevent chilled air from
entering the furnace. If the dampers are
manually operated, there must be a
means of control to prevent the operation
of either system unless the dampers are
in the full heat or full cool position. The
air heated by the furnace shall not pass
through a refrigeration unit unless the
unit is specifically approved for such
service.
Generally, a six-inch clearance between
the air conditioning evaporator coil and
the heat exchanger will provide adequate
airflow through the evaporator coil.
The blower speed must be checked and
adjusted to compensate for the pressure
drop caused by the evaporator coil.
Refer to Appendix B for recommended
wiring and electrical connections of the
air conditioning controls.
COMBUSTION AIR
When a furnace is installed in the full
basement of a typical frame or brick
house, infiltration is normally adequate to
provide air for combustion and draft
operation. If the furnace is installed in a
closet or utility room, two (2) ventilation
openings must be provided connecting to
a well ventilated space (full basement,
living room or other room opening
thereto, but not a bedroom or bathroom).
One opening shall be located 6" from the
top and bottom of the enclosure at the
front of the furnace. For furnaces located
in buildings of unusually tight
construction, such as those with high
quality weather stripping, caulking,
windows and doors, or storm sashed
windows, or where basement windows
are well sealed, a permanent opening
communicating with a well ventilated
attic or with the outdoors shall be
provided, using a duct if necessary. Size
all of the openings and associated
ductwork by the standards provided in
the latest Oil Installation Code editions;
NFPA 31 in the United States, CAN/CSA
B139 in Canada. Take all fuel burning
appliances in the area into consideration
when calculating combustion and
ventilation air requirements.
The Model CAS-2B-90E Furnace Boot
manufactured by Field Controls, Inc. may
be used with the furnace to obtain
combustion air directly from outdoors.
Use of this device does not alter the
need for ventilation air; however, it does
provide a good direct source of
combustion air and is connected directly
to the oil burner.
NOTE: THE VACUUM RELIEF VALVE
(VRV) INCLUDED IN THIS KIT MUST
BE USED IN CONJUNCTION WITH
THE FURNACE BOOT.
CHIMNEY VENTING
The chimney must be sized correctly and
be in good repair. If the chimney is
oversized, there is a high risk of the flue
gases condensing resulting in damage to
the chimney and other venting parts.
This problem may be corrected by the
use of an appropriately sized chimney
liner.
If the chimney serves the
O4HD-091A
furnace only, the vent should be sized at
4-inch minimum, 5-inch maximum. If the
chimney serves the
O4HD-140A
furnace
only, the vent should be sized at 4-inch
minimum, 6-inch maximum. The data
provided in Table 3 is based on
dedicated venting. If the furnace is to be
co-vented with other appliances, refer to
NFPA 211,
Standard for Chimneys,
Fireplaces, Vents, and Solid Fuel-
Burning Appliances,
NFPA 31,
Standard for the Installation of Oil
Burning Equipment
or CAN/CSA
B139
,
Installation Code For Oil Burning
Equipment
for correct sizing information.
NOTE: This furnace is approved for
use with L-Vent.
NOTE: Maximum temperature for L-
Vent is 575°F (300°C).
IMPORTANT
: The chimney must be
capable of providing sufficient draft at all
times for the safe removal of the
products of combustion.
The chimney should be tested under
“winter” conditions; doors and windows
closed, all other fossil fuel burning
appliances on, clothes dryer on,
bathroom fans on, etc. If the chimney
cannot overcome the competition for air,
it will be necessary to access the reason
for it, and take corrective action. If the
chimney is correctly and in good repair, it
will probably be necessary to re-evaluate
the availability of combustion and
ventilation air, and take corrective action.
The flue pipe should be as short as
possible with horizontal pipes sloping
upward toward the chimney at a rate of
one-quarter inch to the foot. The flue
pipe should not be smaller in cross
sectional area than the flue collar on the
furnace. The flue pipe should connect to
the chimney such that the flue pipe
extends into, and terminates flush with
the inside surface of the chimney liner.
Seal the joint between the pipe and the
lining. The chimney outlet should be at
least two feet above the highest point of
a peaked roof. All unused chimney
openings should be closed. Chimneys
must conform to local, provincial or state
codes, or in the absence of local
regulations, to the requirements of the
National Building Code.
See Figure 2 and Table 2 for common
chimney problems and their remedies.
THE FURNACE MUST BE
CONNECTED TO A FLUE HAVING
SUFFICIENT DRAFT AT ALL TIMES
TO ENSURE SAFE AND PROPER
OPERATION OF THE APPLIANCE.
The flue pipe must not be routed through
concealed space, because it must be
visually checked for signs of
deterioration during the annual
inspection and servicing. The flue pipe
must not pass through any floor or
ceiling, but may pass through a wall
where suitable fire protection provisions
have been installed. In the United States,
refer to the latest edition of NFPA 31 for
regulations governing the installation of
oil burning equipment. In Canada, refer
to the latest edition of CAN/CSA B139
for rules governing the installation of oil
burning equipment.
