935CA: Installation, Start-up, Operating and Service and Maintenance Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
5
INTRODUCTION
A190213
Fig. 2 – Upflow/Horizontal Orientations
NOTE:
Downflow not permitted.
This Upflow/Horizontal Category IV condensing furnace is CSA
design-certified as a direct-vent (2-pipe) furnace using outside air for
combustion, see
Fig. 2
. It is also certified as a non-direct vent (1-pipe)
furnace using indoor air for combustion or air from a well-ventilated
attic or crawl space, where permitted by local code.
The furnace is factory-shipped for use with natural gas only and cannot
be converted to propane gas.
These furnaces are not approved for installation in recreational vehicles
outdoors, or in manufactured/mobile homes. When installed on a wood
floor, the furnace must be installed on a factory-supplied accessory
combustible floor base or evaporator coil casing.
This furnace is designed for minimum continuous return-air temperature
of 60°F (15°C) db or intermittent operation down to 55°F (13°C) db such
as when used with a night setback thermostat. Return-air temperature
must not exceed 80°F (27°C) db. Failure to follow these return-air
temperature limits may affect reliability of heat exchangers, motors, and
controls, see
Fig. 3
.
A150573
Fig. 3 – Freeze Protection and Return Air Temperature
The furnace should be sized to provide 100 percent of the design heating
load requirement plus any margin that occurs because of furnace model
size capacity increments. None of the furnace model sizes can be used if
the heating load is less than half of the furnace model’s output capacity.
Use Air Conditioning Contractors of America (Manual J and S);
American Society of Heating, Refrigerating, and Air-Conditioning
Engineers; or other approved engineering method to calculate heating
load estimates and select the furnace. Excessive oversizing of the
furnace may cause the furnace and/or vent to fail prematurely, customer
discomfort and/or vent freezing.
Failure to follow these guidelines is considered faulty installation and/or
misapplication of the furnace; and resulting failure, damage, or repairs
may impact warranty coverage.
For accessory installation details, refer to the applicable instruction
literature.
NOTE:
Remove all shipping materials, loose parts bags, and literature
before operating the furnace, see
Table 2
. The Ultra Low NOx
condensing furnaces also contain an additional parts bag for the
condensate trap, see Condensate Trap section.
A190256
Fig. 4 – Prohibited Installations
Downflow not permitted with any return air configuration.
A93044
Fig. 5 – Installation in a Garage
NOTICE
!
Important Installation and Start-up Procedures
Failure to follow this procedure may result in a nuisance smoke or odor
complaint.
The manifold pressure, gas rate by meter clocking, temperature rise and
operation must be checked after installation. Minor smoke and odor
may be present temporarily after start-up from the manufacturing pro
-
cess. Some occupants are more sensitive to this minor smoke and odor.
It is recommended that doors and windows be open during the first heat
cycle.
THE BLOWER IS LOCATED
TO THE RIGHT OF THE
BURNER SECTION, AND
CONDITIONED AIR IS
DISCHARGED TO THE LEFT.
THE BLOWER IS
LOCATED BELOW THE
BURNER SECTION, AND
CONDITIONED AIR IS
DISCHARGED UPWARD.
THE BLOWER IS
LOCATED TO THE LEFT
OF THE BURNER SECTION,
AND CONDITIONED AIR IS
DISCHARGED TO THE RIGHT.
60
80
/ 27˚C
/ 16˚C
SUPPLY AIR
SEE PRODUCT DATA FOR
ACCESSORY CONDENSATE
TRAP HEATER AND CONDENSATE
DRAIN LINE PROTECTION.
WARNING
!
FIRE HAZARD
Failure to follow this warning could result in personal injury, death
and/or property damage.
Do not install the furnace on its back or hang furnace with control
compartment facing downward. Safety control operation will be
adversely affected. Never connect return-air ducts to the back of the
furnace, see
Fig. 4
.
BACK POSITIONED
DOWNWARD
AIR RETURN
CUT IN BACK
BACK POSITIONED
UPWARD
18-IN. (457.2 mm)
MINIMUM TO BURNERS