Armstrong Air RP16DF Series User manual

507640-05 Page 1 of 25Issue 2245
Save these instructions for future reference
THIS MANUAL MUST BE LEFT WITH THE
HOMEOWNER FOR FUTURE REFERENCE
INSTALLATION AND MAINTENANCE
INSTRUCTIONS
*RP16DF SERIES UNITS
RESIDENTIAL PACKAGED UNITS
Dual Fuel Units
507640-05
11/2022
Improper installation, adjustment, alteration, service, or
maintenance can cause injury or property damage. Refer
to this manual. For assistance or additional information,
consult a licensed professional (or equivalent), HVAC
installer, service agency, or the gas supplier.
WARNING
Do not store combustible materials, including gasoline
and other ammable vapors and liquids, near the unit,
vent pipe, or warm air ducts. Such actions could cause
property damage, personal injury, or death.
WARNING
The installation of the unit, wiring, warm air ducts, venting, etc. must conform to the requirements of the National Fire
Protection Association; the National Fuel Gas Code, ANSI Z223.1 (latest edition) and the National Electrical Code, ANSI/
NFPA No. 70 (latest edition) in the United States; the Canadian Installation Codes CAN/CGA-B149.1 & .2 (latest edition)
and the Canadian Electrical Code Part 1, CSA 22.1 (latest edition) in Canada; and any state or provincial laws, local
ordinances, or local gas utility requirements. Local authorities having jurisdiction should be consulted before installation
is made. Such applicable regulations or requirements take precedence over the general instructions in this manual.
CAUTION
See unit nameplate for Manufacturer
(P) 507640-05
*P507640-05*
If this unit is to be installed in a mobile or manufactured
home application, the duct system must be sized to
achieve static pressures within the manufacturer’s
guidelines. All other installation guidelines must also
be followed. Failure to do so may result in equipment
damage, personal injury, and improper performance of
the unit.
WARNING
Table of Contents
Unit Dimensions ..........................................................2
Roof Curb Dimensions ................................................4
Adjustable Roof Curb Dimensions...............................6
Installation ...................................................................9
Venting.......................................................................11
Duct System ..............................................................12
Filters.........................................................................12
Condensate Drain......................................................13
Gas Piping.................................................................13
Electrical Wiring ........................................................14
Gas Heating Start-Up ...............................................15
Sequence of Operation..............................................17
System Performance.................................................21
Control System Diagnostics ......................................22
Maintenance..............................................................23
Wiring Diagrams........................................................25

Page 2 of 25 507640-05Issue 2245
12.12
3.87
3.62
4.06
26.19
32.20
POWER ENTRY
1-1/8 DIA. KNOCKOUT
LOW VOLTAGE ENTRY
7/8 KNOCKOUT
GAS ENTRY
5.863.07
6.20
17.07
13.44
13.44
14.32
16.06
6.20
40.89
21.63
13.21
TYPICAL DRAIN
LOCATION
CONDENSATE
DRAIN 3/4 NPT
5.75
3.55
4.12
TYPICAL
VENT HOOD
SIDE VIEWS
11.49
2.33
47.66
1.98
16.77
2.48
14.02
47.66
POWER ENTRY
GAS ENTRY
6.94
2.33
11.49 16.07
18.52
3.25
4.56
20.31
21.06
23.19
RETURN
AIR
SUPPLY
AIR
TOP VIEW
Unit Dimensions - Small Base Dual Fuel

507640-05 Page 3 of 25Issue 2245
14.32
4.20
3.76
6.20
17.07
18.19 18.19
16.06
6.20
3.62
4.06
36.20
12.14
30.19
3.87 POWER ENTRY
1-1/8 DIA. KNOCKOUT
LOW VOLTAGE ENTRY
7/8 DIA. KNOCKOUT
GAS SUPPLY
44.89
21.63
13.21
TYPICAL DRAIN
LOCATION
CONDENSATE
DRAIN 3/4 NPT
5.75
3.55
4.12
TYPICAL
VENT HOOD
SIDE VIEWS
TOP VIEW
POWER ENTRY
GAS ENTRY
RETURN
AIR
2.11
19.49
2.39 2.33
11.49 16.07
18.52
6.94
3.25
10.06
19.49
SUPPLY
AIR
25.81
26.56
28.68
11.49
2.33
47.66
56.13
Unit Dimensions - Large Base Dual Fuel

Page 4 of 25 507640-05Issue 2245
NOTE - Roof deck may be omitted within confines of curb.
Insulated
Panels
Opening for Power Entry
Through Unit Base
5-1/2 x 5-5/8 in.
(140 x 31 mm)
Opening for Gas Entry
Through Unit Base
3 x 13 in.
(76 x 330 mm)
44-3/8
(1127)
44-3/8
(1127)
16-7/8
(429)
13-7/8
(352)
2-1/8
(54)
11-1/2
(287)
SUPPLY
OPENING
RETURN
OPENING
8 (203)
14 (356)
18 (457)
24 (610)
3/4 (19)
1 (25)
5-1/2
(140)
5-3/4
(146)
11-1/2
(287)
17-1/4
(438)
1-3/8
(35)
3-3/4
(95)
13
(330)
3
(76)
NOTE - If bottom entry is used, condensate from the heat exchanger may leak during warm ambient temperatures in humid
climates. Ensure that bottom entry is watertight, if used.
Roof Curb Dimensions - Small Base Dual Fuel

507640-05 Page 5 of 25Issue 2245
NOTE - Roof deck may be omitted within confines of curb.
Insulated
Panels
Opening for Power Entry
Through Unit Base
5-1/2 x 5-5/8 in.
(140 x 31 mm)
Opening for Gas Entry
Through Unit Base
3 x 13 in.
(76 x 330 mm)
52-7/8
(1343)
44-3/8
(1127)
19-1/2
(380)
11-1/2
(287)
19-1/2
(380)
2-1/8
(54)
11-1/2
(287)
SUPPLY
OPENING
RETURN
OPENING
8 (203)
14 (356)
18 (457)
24 (610)
3-3/4
(95)
22-7/8
(581)
7 (178)
3/4 (19)
1 (25)
NOTE - If bottom entry is used, condensate from the heat exchanger may leak during warm ambient temperatures in humid
climates. Ensure that bottom entry is watertight, if used.
Roof Curb Dimensions - Large Base Dual Fuel

Page 6 of 25 507640-05Issue 2245
Adjustable Roof Curb Dimensions - Small Base Dual Fuel (Knock-Down Style)
Top Edge
Wood Nailer Strip
Bottom Flange
Typical Slot
Typical Locking Tab
See Cliplock 1000 installation instructions for complete
assembly and installation procedures and requirements.
NOTE:
CLIPLOCK CORNER DETAIL
CURB PROFILE
1
1/2
1-3/4
1
11-5/8
2-1/8
14
1
3-1/2
13-1/2
44-3/8
Bottom Curb
Assembly
Opening for Gas
Entry thru base
11-5/8
5-1/2
5-3/4
3-5/8 1-3/8
17-1/4
13-7/8
16-7/8
44-3/8
Insulated Panels
Opening for Power
Line Entry thru base
NOTE - Roof deck may be omitted within connes of curb.
NOTE - If bottom entry is used, condensate from the heat exchanger may leak during warm ambient temperatures in humid
climates. Ensure that bottom entry is watertight, if used.

507640-05 Page 7 of 25Issue 2245
Top Edge
Wood Nailer Strip
Bottom Flange
Typical Slot
Typical Locking Tab
See Cliplock 1000 installation instructions for complete
assembly and installation procedures and requirements.
NOTE:
CLIPLOCK CORNER DETAIL
CURB PROFILE
1
1/2
1-3/4 1
19-5/8
11-5/8
2-1/8
19-3/8
11-5/8
14
23-1/8
1
5-1/2
5-3/4
3-1/2
3-1/2
13-1/2
6-7/8
52-7/8
44-3/8
Insulated Panels
Opening for Power
Line Entry thru base
Bottom Cur
b
Assembly
Opening for Gas
Entry thru base
NOTE - Roof deck may be omitted within connes of curb.
NOTE - If bottom entry is used, condensate from the heat exchanger may leak during warm ambient temperatures in humid
climates. Ensure that bottom entry is watertight, if used.
Adjustable Roof Curb Dimensions - Large Base Dual Fuel (Knock-Down Style)

Page 8 of 25 507640-05Issue 2245
A
BC
3/4 (76)
6
(152)
1
(25)
11 -1/2
(292)
42-7/8
(1089)
2-1/ 8
(54)
Built-In Rain
Diverter
(Not Shown)
Front Flange
8 (203)
NOTE:
Minimum
Height
4 (102)
Built-In Drip Edge
Unit Base Rail
Unit Base Rail
Clips (4)
Sides and
Back Flange
6 (152)
Unit Base Rail
Clips (4)
Supply
Air
Opening
Return
Air
Opening
Adjustable Roof Curb Dimensions (Welded Style)
Usage A B C
in. mm in. mm in. mm
24,30,36 42-7/8 1089 13-7/8 352 16-7/8 429
42,48,60 51-3/8 1305 19-1/2 495 19-1/2 495

507640-05 Page 9 of 25Issue 2245
Installation
These instructions must be saved for future reference.
These units are single package heat pumps with gas heat,
designed for outdoor installation on a rooftop or slab.
The units are completely assembled. All piping, refrigerant
charge, and electrical wiring are factory installed and
tested. The units require only electric power, gas piping,
condensate drain, and duct connections, plus installation
of the vent cover at the point of installation.
If components are to be added to a unit to meet local codes,
they are to be installed at the dealer’s and/or customer’s
expense.
The size of unit for the proposed installation should be
based on heat loss/heat gain calculation made according
to the methods of Air Conditioning Contractors of America
(ACCA).
In the State of Massachusetts:
This product must be installed by a licensed Plumber
or Gas Fitter. When exible connectors are used, the
maximum length shall not exceed 36”. When lever-type
gas shuto󰀨s are used, they shall be T-handle type.
WARNING
These installation instructions are intended as a
general guide only, for use by an experienced, qualied
contractor.
These units are certied by E.T.L. Testing Laboratories,
Inc.:
• For use as a forced air furnace with cooling unit.
• For outdoor installation only.
• For installation on combustible material.
• For use with natural gas or propane gas. (Conversion
kit required for propane gas application.)
These units are not suitable for use with conventional
venting systems.
Inspection
As soon as the unit is received, it should be inspected
for possible damage during transit. If 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.
Use the following guidelines to select a suitable location
for these units.
1. Unit is designed for outdoor installation only. Unit must
be installed so all electrical components are protected
from water.
2. Condenser coils must have an unlimited supply of air.
3. For ground level installation, use a level prefabricated
pad or use a level concrete slab. Do not tie the
slab to the building foundation. The heat pump unit
foundation should be raised to a minimum of 3” above
nish grade. In areas which have prolonged periods
of temperature below freezing and snowfall, the heat
pump unit should be elevated above the average snow
line. Extra precaution should be taken to allow free
drainage of condensate from defrost cycles to prevent
ice accumulation. The unit should not be located near
walkways to prevent possible icing of surface from
defrost condensate.
4. Maintain level within a tolerance of 1/4” maximum
across the entire length or width of the unit.
5. Do not locate the unit where the combustion air supply
will be exposed to any of the following substances:
• Permanent wave solutions
• Chlorinated waxes and cleaners
• Chlorine-based swimming pool chemicals
• Water softening chemicals
• Deicing salts or chemicals
• Carbon tetrachloride
• Halogen-type refrigerants
• Cleaning solvents (such as perchloroethylene)
• Printing inks, paint removers, varnishes, etc.
• Cements and glues
• Antistatic fabric softeners for clothes dryers
• Masonry acid washing materials
• Chlorinated laundry products
• Hydrochloric acid
Use of Unit During Construction
Use of this unit as a construction heater or air conditioner is
not recommended during any phase of construction. Very
low return air temperatures, harmful vapors and operation
of the unit with clogged or misplaced lters will damage
the unit.
If this unit has been used for heating or cooling of buildings
or structures under construction, the following conditions
must be met or the warranty will be void:
• A room thermostat must control the unit. The use of
xed jumpers that will provide continuous heating or
cooling is not allowed.
• A pre-lter must be installed at the entry to the return
air duct.
• The return air duct must be provided and sealed to
the unit.
• Return air temperature range between 55°F (13°C)
and 80°F (27°C) must be maintained.

Page 10 of 25 507640-05Issue 2245
• Air lters must be replaced and pre-lters must be
removed upon construction completion.
• The input rate and temperature rise must be set per
the unit rating plate.
• The heat exchanger, components, duct system, air
lters and evaporator coil must be thoroughly cleaned
following nal construction clean-up.
• The unit operating conditions (including airow,
cooling operation, ignition, input rate, temperature
rise and venting) must be veried according to these
installation instructions.
Clearances
All units require certain clearances for proper operation
and service. Refer to Table 1 for the minimum clearances
to combustibles, servicing, and proper unit operation. In
the U.S., units may be installed on combustible oors
made from wood or class A, B, or C roof covering material.
In Canada, units may be installed on combustible oors.
Units must be installed outdoors.
Clearance to combustibles below the unit ue is 10 inches,
since the ue points down.
Do not permit overhanging structures or shrubs to
obstruct condenser air discharge outlet, combustion
air inlet, or vent outlet.
Clearance to
Combustibles
Clearance for
Service Access
Front of unit 0 in. 24 in.
Back of unit 0 in. 0 in.
Left side 0 in. 24 in.
Right side (from
vent hood) 12 in. 24 in.
Base of unit 0 in. 0 in.
Top of unit 0 in. 48 in.
Minimum clearance to combustible material below the ue
is 10 inches to allow proper dissipation of ue gasses and
temperatures. For any future service, installer must provide
accommodation to access screws of top and rear panels.
Table 1. Minimum Clearances
Roof Curb Installation
If a roof curb is used, follow the manufacturer’s installation
instructions and be sure that all required clearances are
observed (see Clearances section).
Prior to setting the unit on the roof curb, the shipping
bracket located underneath the unit must be removed.
Remove the two screws in the base rail (located on the
front and rear sides of the unit). The four screws and the
bracket can be discarded. See Figure 1.
Rigging Unit
Exercise care when moving the unit. Do not remove any
packaging until the unit is near the place of installation.
1. Connect rigging to the unit base rails using both holes
in each corner.
Shipping Bracket and Mounting Screws Must be
Removed for Rooftop or Downflow Application
Field-Provided Lifting
Spreaders Recommended
Figure 1.

507640-05 Page 11 of 25Issue 2245
2. All panels must be in place for rigging.
3. Place eld-provided spreaders in place. Spreaders
must be of adequate strength and length (must exceed
unit dimension by 6 inches).
Units may also be moved or lifted with a forklift. The
lengths of the forks of the forklift must be a minimum
of 42 inches.
Before lifting a unit, make sure that the weight is
distributed equally on the cables so that it will lift evenly.
CAUTION
Unpacking
Locate the four stacking brackets at each corner of the top
panel. Remove the screws and washers that secure these
brackets. All screws must be re-installed. The washers and
stacking brackets can be discarded. Remove the bag and
remaining packaging material, which can be discarded.
Locate the four plastic fork slot bumpers on the base rails.
Remove the fasteners and bumpers and discard.
Service Access
Access to all serviceable components is provided by four
removable panels: upper access panel (for blower, ID coil,
and optional lter), heat exchanger access, control access
panel, and compressor access.
As with any Mechanical equipment, personal injury can
result from contact with sharp sheet metal edges. Be
careful when you handle this equipment.
CAUTION
This unit is charged with HFC-410A refrigerant.
Operating pressures for units charged with HFC-410A
are higher than pressures in units charged with HCFC-
22. All service equipment MUST be rated for use with
HFC-410A refrigerant.
WARNING
Venting
The vent outlet must be installed in a location as to prevent
building degradation and must be consistent with the
National Fuel Gas Code, Z223.1 or CAN/CGA-B149.1 &
.2.
The products of combustion are discharged through
a screened opening on the gas heat side panel. The
horizontal vent system shall terminate at least 4 feet below,
4 feet horizontally from, or 1 foot above any door, window,
or gravity air inlet into the building. The vent system shall
terminate at least 3 feet above any forced air inlet located
within 10 feet.
The unit shall be installed in a manner such that snow
accumulation will not restrict the ow of ue products.
Minimum horizontal clearance of 4 feet from electric meters,
gas meters, regulator, and relief equipment is required.
In addition to the above requirements, consideration must
be given to prevent unwanted ice buildup from the vent
condensate. The vent should not be located on the side of
a building where the prevailing winter winds could trap the
moisture, causing it to freeze on the walls or on overhangs
(under eaves). The vent should not be located over a
sidewalk, patio, or other walkway where the condensate
could cause the surface to become slippery.
The products of combustion must not be allowed to
accumulate within a conned space where they may be
recirculated.
Vent Hood Installation
The unit is shipped with the vent hood inside the control
compartment. Locate the vent hood and attach to side of
utility panel with screws provided in the instruction bag
(see Figure 2).
Vent Hood
A
ttach with
Screws
Figure 2. Installing the Vent Cover
If an existing gas furnace is being removed from a
common venting system when this packaged unit is
installed, then read and follow the instructions in the
“Removal of Unit from Common Venting System” section
that follows. Otherwise, you may skip this section.
NOTE:

Page 12 of 25 507640-05Issue 2245
Removal of Unit from Common Venting System
When an existing furnace is removed from a common
venting system serving other appliances, the venting
system is likely to be too large to properly vent the
remaining attached appliances. The following test
should be conducted with each appliance while the other
appliances 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, or other deciencies
which could cause an unsafe condition.
3. Insofar as is practical, close all building doors and
windows between the space in which the appliances
remaining connected to the common venting system
are located and other spaces in the building. Turn on
clothes dryers and any appliance not connected to the
common venting system. Turn on exhaust fans, such
as range hoods and bathroom exhausts, so they will
operate at maximum speed. Do not operate a summer
exhaust fan. Close replace dampers.
4. Following the lighting instructions, place the unit being
inspected in operation. Adjust the thermostat so the
appliance will operate continuously.
5. Test for spillage at the draft control relief opening after
5 minutes of main burner operation. Use the ame of
a match or candle.
6. Follow the preceding steps for each appliance
connected to the common venting system.
7. After it has been determined that each appliance
remaining connected to the common venting system
properly vents when tested as outlined above, return
doors, windows, exhaust fans, replace dampers,
and any other fuel burning appliance to their previous
condition of use.
8. If improper venting is observed during any of the
above tests, the common venting system must be
corrected. See National Fuel Gas Code, ANSI Z223.1
(latest edition) or CAN/CGA B149.1 & .2 Canadian
Installation Codes to correct improper operation of
common venting system.
Duct System
The duct system should be designed and sized according
to the methods in the Air Conditioning Contractors of
America (ACCA) manual that is most appropriate to the
installation application.
A closed return air duct system shall be used. This shall
not preclude use of economizers or outdoor fresh air
intake. It is recommended that supply and return air duct
connections at the unit be made with exible joints.
The supply and return air duct systems should be designed
for the CFM and static requirements of the job. They
should not be sized by matching the dimensions of the
duct connections on the unit.
The unit is shipped ready for horizontal ow (side duct
connections) or downow (bottom duct connections). All
units are equipped with a drain pan overow switch that is
installed and wired at the factory. Duct attachment screws
are intended to go into the duct panel anges. Duct to unit
connections must be sealed and weather proofed.
For horizontal duct systems:
1. Remove the duct covers on side of the unit. They can
be discarded.
2. Install the duct system to the unit.
For downow duct systems:
1. Remove the duct covers on side of the unit. Keep the
screws and the covers as they will be re-installed later.
2. Remove the downow duct covers located inside unit.
Remove the four screws securing each cover. Remove
the covers from the unit. They can be discarded.
3. Remove screws located between the supply and
return air openings that attach the blower deck to the
base pan. These screws can interfere with bottom duct
connections or roof curb seals. Discard these screws.
4. Install the duct system to the unit.
5. Re-install the duct covers removed in Step 1.
Filters
Air lters are not supplied with the unit. A eld-provided air
lter must always be installed ahead of the evaporator coil
and must be cleaned or replaced if necessary. Dirty lters
will reduce the airow of the unit.
An optional lter rack kit may be purchased separately
for installation inside the unit’s coil compartment. Air lter
sizes are shown in Table 2 for use with lter rack kit.

507640-05 Page 13 of 25Issue 2245
The lter rack must be installed prior to installation of
the unit in applications where access to the rear panel
is limited.
NOTE:
Table 2. Unit Air Filter Sizes - inches
Unit Model Filter 1 Filter 2
24, 36 14 x 20 x 1 20 x 20 x 1
48, 60 20 x 20 x 1
Condensate Drain
This package unit is equipped with a 3/4” FPT coupling
for condensate line connection. Plumbing must conform
to local codes. Use a sealing compound on male pipe
threads.
Do not operate unit without a drain trap. The condensate
drain is on the negative pressure side of the blower;
therefore, air being pulled through the condensate line will
prevent positive drainage without a proper trap.
The condensate drain line must be properly trapped,
routed to a suitable drain and primed prior to unit
commissioning.
NOTE: Install drain lines and trap so they do not block
service access to the unit.
See Figure 3 for proper drain arrangement. The drain line
must pitch to an open drain or pump to prevent clogging
of the line. Seal around the drain connection with suitable
material to prevent air leakage into the return air system.
To prime trap, pour several quarts of water into drain,
enough to ll drain trap and line.
Drain lines should be hand tight only. Do not use tools
to tighten tting into drain.
CAUTION
Minimum Pitch:
1 in (25) Per 10”
(3048 mm) of
Line
Open
Vent
Unit
Trap must be deep enough to o󰀨set maximum static di󰀨erence
(generally, 3 inches (76 mm) minimum). In addition, the drain line
must be supported if longer than 10 feet.
Trap must be primed at start-up.
Mounting
Frame
Figure 3. Typical Condensate Drain Connection
Gas Piping
Proper sizing of gas piping depends on the cubic feet
per hour of gas ow required, specic gravity of the gas,
and length of run. National Fuel Gas Code Z223.1 (latest
edition) should be followed in all cases unless superseded
by local codes or gas company requirements. In Canada,
refer to CAN/CGA B.149.1 & .2 (latest edition).
The heating value of the gas may di󰀨er with locality. The
value should be checked with the local gas utility. For
temperature rise of unit, see unit rating plate.
Gas piping recommendations:
• A drip leg and a ground joint union must be installed in
the gas piping. A ground joint union is recommended
by the manifold/valve.
• When required by local codes, a manual shuto󰀨 valve
may have to be installed outside of the unit.
• Use pipe thread sealing compound resistant to
propane gas sparingly on male threads.
Never use a ame to check for gas leaks. Explosion
causing injury or death may occur.
WARNING

Page 14 of 25 507640-05Issue 2245
• The gas supply should be a separate line and installed
in accordance with all safety codes listed on Page 1.
After the gas connections have been completed, open
the main shuto󰀨 valve admitting normal gas pressure
to the mains. Check all joints for leaks with soapy
solution or other material suitable for the purpose.
• The furnace and its eld supplied manual shuto󰀨 valve
must be disconnected from the gas supply piping
system during any pressure testing of that system at
test pressures in excess of 1/2 PSIG (3.48kPa).
• A 1/8” N.P.T. plugged tapping, accessible for test
gauge connections, must be installed immediately
upstream of the gas supply connection to the furnace.
Gas Connection
The gas supply line is routed through the gas entry location
on the side of the unit (see Figure 4). A grommet is provided
in the instruction bag and should be used to seal the gas
supply line to the gas entry of the control compartment.
Thermostat
Wire Entry
High Voltage
Power Entry
Gas Entry
Figure 4.
The furnace must be isolated from the gas supply piping
system by closing the eld supplied manual shuto󰀨 valve
during any pressure testing of gas supply piping system
at test pressures equal to or less than 1/2 psig or 14”
w.c. If the piping system is to be tested at pressures in
excess of 1/2 psig, the furnace and its individual shuto󰀨
valve must be disconnected from the gas supply piping
system.
WARNING
LP/Propane Units, Tanks, and Piping
Units are shipped equipped for natural gas, but can
be converted to LP/propane in the eld by an approved
licensed technician. If conversion is required, use the
approved conversion kit.
When converting a low NOx unit (designated by an L in
some model numbers) to propane, the NOx inserts must
be removed.
All LP/propane gas equipment must conform to the safety
standards of the National Fire Protection Association.
For satisfactory operation, LP/propane gas pressure must
be a minimum of 11” w.c. at the unit under full load.
Complete information regarding tank sizing for
vaporization, recommended regulator settings, and pipe
sizing is available from most regulator manufacturers and
LP/propane gas suppliers.
Check all connections for leaks when piping is completed,
using a soapy, non-chlorine based solution. Some soaps
used for leak detection are corrosive to certain metals.
Carefully rinse piping thoroughly after completing
leak detection.
NOTE: An optional bottom-entry gas kit is available for
these units. See the kit instructions for proper installation
details.
Danger of explosion. Can cause injury or product or
property damage. Do not use matches, candles, ame
or other sources of ignition to check for leaks.
WARNING
If a exible gas connector is required or allowed by
the authority that has jurisdiction, black iron pipe shall
be installed at the gas valve and must extend outside
the cabinet. The exible connector can then be added
between the black iron pipe and the gas supply line.
WARNING
Electrical Wiring
All wiring should be done in accordance with the National
Electrical Code, ANSI/NFPA No. 70 (latest edition);
Canadian Electrical Code Part 1, CSA C22.1 (latest
edition); or local codes where they prevail. Use wiring with
a temperature limitation of 75°C minimum. Run the 208 or
230 volt, 60 hertz electric power supply through a fused
disconnect switch to the control box of the unit and connect
as shown in the wiring diagram located on the inside of the
control access panel.
Power supply to the unit must be N.E.C. Class 1, and must
comply with all applicable codes. A fused disconnect switch
should be eld provided for the unit. The switch must be
separate from all other circuits. If any of the wire supplied
with the unit must be replaced, replacement wire must be
of the type shown on the wiring diagram. Electrical wiring

507640-05 Page 15 of 25Issue 2245
must be sized to carry minimum circuit ampacity marked
on the unit. Use copper conductors only. Each unit must be
wired with a separate branch circuit and be properly fused.
NOTE: An optional bottom-entry power kit is available for
these units. See the kit instructions for proper installation
details.
208/230 Line Voltage Wiring
If 208 Volt is supplied, transformer connection
must be changed
SINGLE PHASE POWER SUPPLY
GROUND
LUG
CONTACTOR FIELD-SUPPLIED FUSED
OR CIRCUIT BREAKER
DISCONNECT
Figure 5.
When connecting electrical power and control wiring
to the unit, waterproof type connectors must be used
so that water or moisture cannot be drawn into the unit
during normal operation.
CAUTION
Thermostat
This dual fuel system requires the use of a eld supplied
dual fuel thermostat. The thermostat must be capable
of monitoring outdoor ambient temperature, control two
stages of Cool (Y1, Y2), control two stages of Heat Pump
(Y1, Y2) and control the changeover from Heat Pump (Y)
to Gas Heat (W).
The room thermostat should be located on an inside
wall where it will not be subject to drafts, sun exposure,
or heat from electrical xtures or appliances. Follow the
manufacturer’s instructions enclosed with thermostat for
general installation procedure. Color-coded insulated wires
(#18 AWG) should be used to connect the thermostat to
the unit.
Compressor
Units are shipped with compressor mountings factory-
adjusted and ready for operation.
Do not loosen compressor mounting bolts.
CAUTION
Figure 6. Typical Wiring Connections
R
G
W
O
Y2
Y1
C
R
G
W
O
Y2
Y1
C
THERMOSTAT OUTDOOR UNIT
Red
Blue
Yellow
Yellow w/
Blue Stripe
Orange
White
Green
!CAUTION
required by the indoor thermostat. Refer to the
thermostat installation instructions.
Do not connect connections except when
C
SINGLE PHASE
L2 L1 GROUND
SCREW
POWER WIRING
208/230-1-60
(75° MIN. WIRE)
POWER WIRING
24V CONTROL WIRING
(NEC CLASS 2)
Gas Heating Start-Up
For Your Safety Read Before Lighting
Furnace is equipped with a direct ignition control. Do
not attempt to manually light the burners.
CAUTION
Pre-Start Check List
Complete the following checks before starting the unit:
1. Check the type of gas being supplied. Be sure it is the
same as listed on the unit nameplate.
2. Make sure that the vent cover has been properly
installed.
To Light Main Burners:
1. Turn o󰀨 electrical power to unit.
2. Turn the thermostat to lowest setting.
3. Slide the gas valve switch to the “ON” position (see
Figure 7).
4. Turn on electrical power to the unit.

Page 16 of 25 507640-05Issue 2245
5. Set the room thermostat to the desired temperature.
(If the thermostat “set” temperature is above room
temperature after the pre-purge time expires, main
burners will light.)
NOTE: Gas heat is used by the thermostat for second-
stage above changeover outdoor temperature and rst
stage heat below changeover. Adjustments to thermostat
settings may be required to verify gas heating operation.
To Shut Down Main Burners:
1. Turn o󰀨 electrical power to unit.
2. Slide the gas valve switch to the “OFF” position (see
Figure 7).
MANIFOLD
PRESSURE OUTLET
INLET
PRESSURE
PORT
MANIFOLD
PRESSURE
ADJUSTMENT
SCREW
Figure 7. Gas Valve
Post-Start Check List
After the entire control circuit has been energized and the
heating section is operating, make the following checks:
1. Check for gas leaks, using soapy solution, in the unit
piping as well as the supply piping.
2. Check for correct manifold gas pressures (see Manifold
Gas Pressure Adjustment Regulator sections).
3. Check the supply gas pressure. It must be within the
limits shown on the rating plate. Supply pressure
should be checked with all gas appliances in the
building at full re. At no time should the standby gas
pressure exceed 13” w.c., nor the operation pressure
drop below 5” w.c. for natural gas units or 11” w.c. for
propane gas. If gas pressure is outside these limits,
contact the gas supplier for corrective action.
4. Adjust temperature rise to the range specied on the
rating plate.
Manifold Gas Pressure Adjustment Regulator –
Natural Gas
For purpose of input adjustment, the minimum permissible
gas supply pressure is 5” w.c. for natural gas.
Gas input must never exceed the input capacity shown on
the rating plate. The furnace is equipped for natural gas
rated inputs with manifold pressure of 3.5” w.c.
The manifold pressure can be measured by shutting o󰀨
the gas, removing the pipe plug in the downstream side
of the gas valve, and connecting a water manometer or
gauge. Under no circumstances should the nal manifold
pressure vary more than 0.3” w.c. from the above specied
pressures. To adjust the regulator, turn the adjusting screw
on the regulator clockwise to increase pressure and input
or counterclockwise to decrease pressure and input. See
Figure 7 to assist in locating the regulator on the gas valve.
Check the furnace rate by observing the gas meter, making
sure all other gas appliances are turned o󰀨. The test hand
on the meter should be timed for at least one revolution,
noting the number of seconds per revolution. The heating
value of the gas can be obtained from the local utility.
Example: By actual measurement, it takes 38 seconds for
the hand on the 1-cubic foot dial to make a revolution with
a 100,000 BTU/HR furnace running. The result is 99,750
BTU/HR, which is close to the 100,000 BTU/HR rating of
the furnace.
BTU/HR
Input =
Cubic Feet per
Revolution x 3600 x Heating
Value
# Seconds per
Revolution
Manifold Gas Pressure Adjustment Regulator –
LP/Propane Gas
LP/propane units require a LPG regulator on both the gas
valve and on the LP/propane tank.
For purpose of input adjustment, the minimum permissible
gas supply pressure (inlet side of gas valve) is 11” w.c. for
LP/propane.
If at any time ignition is slow and burner does not seem to
be operating correctly, check manifold pressure (outlet side
of the gas valve). It should be 10” to 10.5” w.c. pressure
for LP/propane.
The furnace is designed to obtain rated input at 10”
w.c. manifold pressure for propane.
High Altitude
The input rate shown on the rating plate is for elevations
up to 2000 feet. For elevations from 2001 to 4500 feet,
the input rate is reduced by 5%. For elevations above
4500 feet, refer to the National Fuel Gas Code Z223.1
(latest edition) or the Canadian Installation Codes CAN/
CGA-B149.1 & B149.2 for further details.
To check this pressure:
1. Slide the gas valve switch to the “OFF” position (see
Figure 7).
2. Remove plug on valve marked “OUTLET PRESSURE.”
3. Install a water manometer.

507640-05 Page 17 of 25Issue 2245
4. Slide the gas valve switch to the “ON” position and
initiate a call for heat. If manifold pressure must be
adjusted, remove cap from pressure regulator and
turn adjustment screw clockwise to increase pressure
or counterclockwise to reduce pressure.
5. After checking pressure, turn gas o󰀨, remove
manometer tting, and replace pipe plug and regulator
cap.
6. Put furnace in operation and check plug for leaks
using soapy solution.
Burner and Burner Orice Instructions
To check or change burners or burner orices:
1. Close the main manual gas shuto󰀨 valve and turn
o󰀨 all power to unit.
2. Remove the burner access panel.
3. Disconnect the union in the gas supply line upstream
of the gas valve and downstream of the manual shuto󰀨
valve.
4. Label wires going to the gas valve, then disconnect
the wires.
5. To change orice:
a. Remove screws that fasten the manifold to the
burner box assembly and remove the manifold.
b. Remove the orices, then install replacement
orices.
c. To reassemble: Reverse above steps, making
sure orices are inserted into the orice holders
on the back end of the burners, and that burners
are level and centered on each burner opening in
the vest panel.
6. To remove or service burners:
a. Label and disconnect the wires to the rollout
switch and disconnect the igniter and ame
sensor leads at the ignition control.
b. Remove the screws that secure the burner box
assembly to the vest panel and remove the
assembly from the unit.
c. Remove the screws that fasten the burner rack
and bottom shield assembly to the burner box.
Burners are now accessible for removal.
d. To Reassemble: Reverse above steps.
7. After reassembly of all parts is complete and all wires
are reconnected, open the main manual gas shuto󰀨
valve; check for and correct any gas leaks. Turn
electrical power on, initiate a call for heat, and check
for proper burner operation.
8. Install burner access panel.
Crankcase Heater (if used)
Some models may be equipped with a crankcase heater
to prevent excessive migration of liquid refrigerant into the
compressor during o󰀨 cycles. Power must be maintained
to the unit to keep this feature active.
Except as required for safety while servicing, do not open
the system disconnect switch.
Sequence of Operation
Blower Control
Units are equipped with a variable speed motor that is
capable of maintaining a specied CFM throughout the
external static range. A particular CFM can be obtained by
positioning jumpers (COOL, HEAT, and ADJUST) on the
blower control. The HEAT and COOL jumpers are labeled
A, B, C and D. Each of the numbers corresponds with an
air volume (CFM) setting. The ADJUST jumper is labeled
Test, -, +, and Norm. The + and - pin settings are used to
add or subtract a percentage of the CFM selected. The
Test jumper is used to operate the motor in the test mode.
Figure 9 shows the blower control.
Figure 8.

Page 18 of 25 507640-05Issue 2245
The CFM LED located on the blower control ashes one
time per 100 cfm to indicate selected blower speed. For
example, if the unit is operating at 1200 CFM, the CFM
LED will ash 12 times. If the CFM is 1150, the CFM
LED will ash 11 full times plus one fast or half ash. At
times, the light may appear to icker or glow. This takes
place when the control is communicating with the motor
between cycles. This is normal operation. Read through
the jumper settings section before adjusting the jumper to
obtain the appropriate blower speed. To change jumper
positions, gently pull the jumper o󰀨 the pins and place it
on the desired set of pins. The following section outlines
the di󰀨erent jumper selections available and conditions
associated with each one. Refer to Figure 9.
From the engineering handbook and/or specication
sheet, determine which row most closely matches the
desired CFM. Once a specic row has been chosen (+,
NORMAL, or -), CFM volumes from other rows cannot be
used. Below are descriptions of the jumper selections.
The variable speed motor slowly ramps up to and down
from the selected air ow during both cooling and heating
demand. This minimizes noise and eliminates the initial
blast of air when the blower is initially energized.
ADJUST
The ADJUST pins allow the motor to run at normal speed,
approximately 10 percent higher, or approximately 10
percent lower than normal speed.
The TEST pin is available to bypass the blower control
and run the motor at approximately 70 percent to make
sure that the motor is operational. This is used mainly in
troubleshooting. The G terminal must be energized for the
motor to run.
COOL
The COOL jumper is used to determine the CFM during
cooling operation. This jumper selection is activated for
cooling when Y1/Y2 and O are energized.
The blower motor runs at 80 percent of the selected air
ow for the rst 7-1/2 minutes of each cooling demand.
This feature allows for greater humidity removal and saves
energy.
In the cooling mode, the blower control delays blower
operation for 5 seconds after the compressor starts. The
blower continues to operate for 90 seconds after the
compressor is de-energized.
HEAT
The HEAT jumper is used to determine CFM during gas
heat operation only. These jumper selections are activated
only when W1 is energized.
CONTINUOUS FAN
When the thermostat is set for “Continuous Fan” operation
and there is no demand for heating or cooling, the blower
control will provide 50 percent of the COOL CFM selected.
DEHUMIDIFICATION
The blower control includes an HUM terminal, which
provides for connection of a humidistat. The JV1 resistor
on the blower control must be cut to activate the HUM
terminal. The humidistat must be wired to open on humidity
rise. When the dehumidication circuit is used, the variable
speed motor will reduce the selected air ow rate by 25
percent when humidity levels are high. An LED (D1) lights
when the blower is operating in the dehumidication mode.
Cooling System
The cooling system is factory-charged with HFC-R-410A.
The compressor is hermetically sealed and base-mounted
with rubber-insulated bolts.
Cooling
When the thermostat calls for cooling, R is closed to Y1
and O (see the wiring diagrams starting on Page 25).
This action completes the low voltage control circuit,
energizing the compressor, condenser fan motor, and
blower motor. Second-stage cooling is initiated by the
thermostat energizing Y2 and O.
Unit compressors have internal protection. In the event there
is an abnormal rise in the temperature of the compressor,
the protector will open and cause the compressor to stop.
The thermostat automatically closes the R to G circuit,
which also brings on the indoor blower at the same time.
Upon satisfying cooling demand, the thermostat will open
the above circuits and open the main contactor, stopping
the compressor and outdoor fan. If the unit is equipped
with a delay timer, the blower will continue to operate for 60
to 90 seconds, which improves system e󰀩ciency.
A combustion air inducer operates for the rst 10 seconds
of every cooling cycle to prevent insects from nesting in
the ue outlet.
Heating - Heat Pump Stage
Upon heating demand, the thermostat closes circuit R to
Y1, which closes the unit contactor, starting the compressor
and outdoor fan. Second-stage heating is initiated when
the thermostat energizes Y2, or when the outdoor ambient
temperature is below the lock-in temperature (see Second-
Stage Lock-In section). The reversing valve is not energized
in the heating mode. The thermostat again automatically
brings on the indoor fan at the same time. Upon satisfying
heating demand, the thermostat opens above circuits and
stops unit operation.
NOTE: O is de-energized in heat pump mode.

507640-05 Page 19 of 25Issue 2245
Defrost System
Demand Defrost System
The demand defrost system measures di󰀨erential
temperatures to detect when the system is performing
poorly because of ice build-up on the outdoor coil. The
system “self-calibrates” when the defrost system starts
and after each system defrost cycle. The demand defrost
components on the control board are listed below.
NOTE: The demand defrost system accurately measures
the performance of the system as frost accumulates on the
outdoor coil. This typically will translate into longer running
time between defrost cycles as more frost accumulates on
the outdoor coil before the board initiates defrost cycles.
Figure 9. Defrost Control Board
(2-Ton Units)
TEST PINS
DEFROST
TERMINATION
PIN SETTINGS
SENSOR
PLUG-IN
(COIL &
AMBIENT
SENSORS)
DELAY PINS
REVERSING
VALVE
PRESSURE
SWITCH
CIRCUIT
CONNECTIONS
LOW
AMBIENT
THERMOSTAT
PINS
DIAGNOSTIC
LEDs
24V TERMINAL
STRIP
CONNECTIONS
Note -
Component
Locations Vary
by Board
Manufacturer
Defrost System Sensors
Sensors connect to the defrost board through a eld–
replaceable harness assembly that plugs into the board.
Through the sensors, the board detects outdoor ambient
and coil fault conditions. As the detected temperature
changes, the resistance across the sensor changes.
Sensor resistance values can be checked by ohming
across pins.
NOTE: When checking the ohms across a sensor, be
aware that a sensor showing a resistance value that is not
within the range shown, may be performing as designed.
However, if a shorted or open circuit is detected, then the
sensor may be faulty and the sensor harness will needs to
be replaced.
Sensor Temperature
Range °F (°C)
Red LED
(DS1)
Pins / Wire
Color
Outdoor
(ambient)
-35 (-37) to
120 (48)
280,000 to
3750
3 & 4
(black)
Coil -35 (-37) to
120 (48)
280,000 to
3750
5 & 6
(brown)
NOTE: Sensor resistance decreases as sensed temperature
increases.
Table 3. Sensor Temp. / Resistance Range
Coil Sensor
The coil temperature sensor considers outdoor
temperatures below -35°F (-37°C) or above 120°F (48°C)
as a fault. If the coil temperature sensor is detected as
being open, shorted or out of the temperature range
of the sensor, the board will not perform demand or
time/temperature defrost operation and will display the
appropriate fault code. Heating and cooling operation will
be allowed in this fault condition.
NOTE: The coil temperature probe is designed with a
spring clip to allow mounting to the outside coil tubing. Coil
sensor location is important for proper defrost operation.
Ambient Sensor
The ambient sensor considers outdoor temperatures
below -35°F (-37°C) or above 120°F (48°C) as a fault. If the
ambient sensor is detected as being open, shorted or out
of the temperature range of the sensor, the board will not
perform demand defrost operation. The board will revert
to time/temperature defrost operation and will display the
appropriate fault code. Heating and cooling operation will
be allowed in this fault condition.
NOTE: Within a single room thermostat demand, if 5-strikes
occur, the board will lockout the unit. Control board 24 volt
power “R” must be cycled “OFF” or the “TEST” pins on
board must be shorted between 1 to 2 seconds to reset
the board.
Defrost Temperature Termination Shunt (Jumper)
Pins
The defrost board selections are: 50, 70, 90, and 100°F
(10, 21, 32 and 38°C). The shunt termination pin is factory
set at 50°F (10°C). If the temperature shunt is not installed,
the default termination temperature is 90°F (32°C).
Delay Mode
The defrost system has a eld-selectable function to
reduce occasional sounds that may occur while the unit is
cycling in and out of the defrost mode. When a jumper is
installed on the DELAY pins, the compressor will be cycled
o󰀨 for 30 seconds going in and out of the defrost mode.
Units are shipped with jumper installed on DELAY pins.
NOTE: The 30 second compressor delay feature (known
as the quiet shift) must be deactivated during any unit

Page 20 of 25 507640-05Issue 2245
performance testing. The feature is deactivated by
removing the jumper located on the compressor delay pins
on the control board mounted inside the unit control box.
This feature is optional for the homeowner, but may impact
testing performance.
Defrost Operation
The defrost control system has three basic operational
modes: normal, calibration, and defrost.
• Normal Mode—The demand defrost system monitors
the O line, to determine the system operating mode
(heat/cool), outdoor ambient temperature, coil
temperature (outdoor coil) and compressor run time to
determine when a defrost cycle is required.
• Calibration Mode—The board is considered
uncalibrated when power is applied to the board,
after cool mode operation, or if the coil temperature
exceeds the termination temperature when it is in heat
mode.
Calibration of the board occurs after a defrost cycle
to ensure that there is no ice on the coil. During
calibration, the temperature of both the coil and
the ambient sensor are measured to establish the
temperature di󰀨erential which is required to allow a
defrost cycle.
• Defrost Mode—The following paragraphs provide a
detailed description of the defrost system operation.
Defrost Cycles
The control board initiates a defrost cycle based on either
frost detection or time.
• Frost Detection—If the compressor runs longer than
30 minutes and the actual di󰀨erence between the
clear coil and frosted coil temperatures exceeds the
maximum di󰀨erence allowed by the control, a defrost
cycle will be initiated.
IMPORTANT - The control board will allow a greater
accumulation of frost and will initiate fewer defrost
cycles than a time/ temperature defrost system.
• Time—If 6 hours of heating mode compressor run
time has elapsed since the last defrost cycle while the
coil temperature remains below 35°F (2°C), the control
board will initiate a defrost cycle.
Actuation
When the reversing valve is de-energized, the Y1 circuit is
energized, and the coil temperature is below 35°F (2°C),
the board logs the compressor run time. If the board is not
calibrated, a defrost cycle will be initiated after 30 minutes
of heating mode compressor run time. The control will
attempt to self-calibrate after this (and all other) defrost
cycle(s).
Calibration success depends on stable system
temperatures during the 20-minute calibration period. If
the board fails to calibrate, another defrost cycle will be
initiated after 45 minutes of heating mode compressor
run time. Once the control board is calibrated, it initiates
a demand defrost cycle when the di󰀨erence between
the clear coil and frosted coil temperatures exceeds the
maximum di󰀨erence allowed by the control OR after 6
hours of heating mode compressor run time has been
logged since the last defrost cycle.
NOTE: If ambient or coil fault is detected, the board will not
execute the “TEST” mode.
Termination
The defrost cycle ends when the coil temperature exceeds
the termination temperature or after 14 minutes of defrost
operation. If the defrost is terminated by the 14-minute
timer, another defrost cycle will be initiated after 30 minutes
of run time.
5-Strike Lockout Feature
The internal control logic of the board counts the pressure
switch trips only while the Y1 (Input) line is active. If a
pressure switch opens and closes four times during a Y1
(Input), the control logic will reset the pressure switch trip
counter to zero at the end of the Y1 (Input). If the pressure
switch opens for a fth time during the current Y1 (Input),
the control will enter a lockout condition.
The 5-strike pressure switch lockout condition can be reset
by cycling OFF the 24-volt power to the control board or by
shorting the TEST pins between 1 and 2 seconds. All timer
functions (run times) will also be reset.
If a pressure switch opens while the Y1 Out line is engaged,
a 5-minute short cycle will occur after the switch closes.
Diagnostic LEDs
The defrost board uses two LEDs for diagnostics. The
LEDs ash a specic sequence according to the condition
as shown in Table 4.