GENERAL INFORMATION
DESCRIPTION
This Category I furnace is designed for installation in a residen-
tial or commercial application. A Category 1 furnace has a fan
assisted combustion system equipped with an integral me-
chanical means to draw products of combustion through the
combustion chamber and heat exchanger. It may be installed
in a basement, garage, equipment room, alcove, attic or any
other indoor location where all required clearances to combus-
tibles and other restrictions are met. It is designed for natural
gas-fired operation, but may be converted to propane (LP).
High altitude and propane (LP) changes or conversions re-
quired in order for the appliance to satisfactorily meet the
application must be made by an authorized distributor: in
Canada, a certified conversion station or other qualified
agency, using factory specified and/or approved parts.
P4UC furnaces may be used only as Category 1 units.
The furnace must be installed so that all electrical components
are protected from water.
INSPECTION
As soon as a unit is received, it should be inspected for possible
damage during transit. If the damage is evident, the extent of
the damage should be noted on the carrier’s freight bill.
A separate request for inspection by the carrier’s agent should be
made in writing. Also, before installation, the unit should be
checked for screws or bolts which may have loosened in transit.
NOTES, CAUTIONS & WARNINGS
The installer should pay particular attention to the words:
NOTE, CAUTION and WARNING. NOTES are intended to
clarify or make the installation easier. CAUTIONS are given to
prevent equipment damage. WARNINGS are given to alert the
installer that personal injury and/or equipment or property
damage may occur if installation procedures are not handled
properly.
WARNING: The furnace area must not be used as a
broom closet or for any other storage purposes, as a
fire hazard may be created. Never store items such
as the following on, near or in contact with the furnace.
1. Spray or aerosol cans, rags, brooms, dust mops,
vacuum cleaners or other cleaning tools.
2. Soap powders, bleaches, waxes or other cleaning com-
pounds; plastic items or containers; gasoline, kerosene,
cigarette lighter fluid, dry-cleaning fluids or other volatile
fluid.
3. Paint thinners and other painting compounds.
4. Paper bags, boxes or other paper products.
WARNING: Never operate the furnace with the
blower door removed. To do so could result in serious
personal injury and/or equipment damage.
WARNING: Each furnace in this series is a Category
I furnace, suitable for common venting with other
gas-fired appliances as allowed by the National Fuel
Gas Code, NFPA 54/ANSI Z223.1-latest edition.
WARNING: This appliance is not to be used for
temporary heating of buildings or structures under
construction.
WARNING: Do not install this furnace in a corrosive
or contaminated atmosphere.
WARNING: Do not install this furnace in a mobile
home or recreational vehicle.
WARNING: Furnaces shall not be installed directly on
carpeting, tile or other combustible material other than
wood flooring.
LIMITATIONS AND LOCATION
This furnace should be installed in accordance with all na-
tional/local building/safety codes and requirements, or in the
absence of local codes, with the National Fuel Gas Code, ANSI
Z223.1 - (latest edition) or, in Canada, CAN/CGA B149.1 or .2
- (latest edition), and other applicable codes.
Use only the type of gas approved for this furnace; refer to the
furnace rating plate.
WARNING: Only use natural gas in furnaces de-
signed for natural gas. Only use propane (LP) gas for
furnaces that have been properly converted to use
propane (LP) gas. Do not use this furnace with bu-
tane. Using wrong gas could create a hazard, result-
ing in damage, injury or death.
For installations above 2,000 feet, reduce input 4% for each
1,000 feet above sea level. Canadian installations must be
derated 10% for elevations from 2,000 ft. to 4,500 ft. Accessory
high altitude kits are available to properly derate furnace.
TABLE OF CONTENTS
GENERAL INFORMATION
Description .................................................................2
Inspection ...................................................................2
Notes, Cautions & Warnings ......................................2
Limitations and Locations ......................................2-3
Clearances .................................................................3
Nomenclature.............................................................3
Dimensions ................................................................4
Ratings & Physical Data ............................................4
Unit Wiring Diagram .................................................13
Blower Performance ................................................14
UNIT INSTALLATION
Combustion Air & Vent System ..............................3, 5
Venting .......................................................................5
Ductwork .................................................................5-6
Filters (Upflow/Horizontal)..........................................6
Gas Piping..................................................................7
Electrical Connections ...............................................7
Safety Conrols............................................................8
Start-Up & Adjustments............................................ 11
Ignition System Checkout/Adjustment .......................8
Adjustment of Manifold Gas Pressure .......................9
Checking Gas Input....................................................8
Adjustment of Temperature Rise...........................9-10
Adjustment of Fan Off Settings ................................10
OPERATION & MAINTENANCE
Sequence of Operation .......................................10-11
Maintenance............................................................. 11
Air
Filters........................................................... 11
Lubrication ........................................................ 11
Burners ............................................................. 11
Heat
Exchangers .............................................. 11
Blower ............................................................... 11
Troubleshooting...................................................11-12
Troubleshooting
Chart ......................................15
650.64-N4
2
Unitary Products Group
