Nordyne G6RL 90+, G6RC 90+, G6RD 93+ User Manual

Residential Gas Furnaces

Installation Instructions

G6RC Series 90+ Upflow Condensing Furnace
G6RD Series 93+ Upflow Condensing Furnace
G6RL Series 90+ Downflow Condensing Furnace

G6RC 90+, G6RD 93+ Upflow G6RL 90+ Downflow

!

WARNING:

Improper installation, adjustment, al­teration, service, or maintenance can
cause injury or property damage. Re­fer to this manual for assistance. For
additional information consult a quali­fied installer, service agency, or the
gas supplier.

These instructions are primarily intended to
assist qualified individuals experienced in
the proper installation of this appliance.
Some local codes require licensed installa­tion/service personnel for this type of equip­ment. Read all instructions carefully before
starting the installation.

DO NOT DESTROY. PLEASE READ CARE­FULLY AND KEEP IN A SAFE PLACE FOR
FUTURE REFERENCE.

!

FOR YOUR SAFETY:

Do not store or use gasoline or other
flammable vapors and liquids in the
vicinity of this or any other appliance.

!

FOR YOUR SAFETY:

WHAT TO DO IF YOU SMELL GAS:

• Do not try to light any appliance.

• Do not touch any electrical switch; do
not use any phone in your building.

• Immediately call your gas supplier
from a neighbor's phone. Follow the
gas supplier's instructions.

• If you cannot reach your gas supplier,
call the fire department.

• Extinguish any open flame.

Table of Contents

Furnace Specifications ......................................................................................................... ... 4-5

Furnace Airflow Data.......................................................................................................... 6-7

Installation Requirements ...................................................................................................... .... 8

Supply Air Plenum Installation ..................................................................................................9

Installation on a Concrete Slab ............................................................................................. 9

Installation on a Combustible Floor....................................................................................... 9

Circulating Air Supply............................................................................................................... 10

Return Air ............................................................................................................................ 11

Venting and Combustion Air Requirements .......................................................................... 11

Air Requirements for One-Pipe Installation ........................................................................ 13

Installation in An Unconfined Space ................................................................................... 13

Installation in A Confined Space ......................................................................................... 13

• Air From Inside .................................................................................................................. 1 3

• Air Directly Through An Exterior Wall ............................................................................... 14

• Outdoor Air Through Vertical Openings or Ducts ............................................................. 14

• Outdoor Air Through Horizontal Openings or Ducts......................................................... 14

Venting Requirements .............................................................................................................. 1 4

Vent Pipe Material ............................................................................................................... 14

Vent Pipe Length and Diameter .......................................................................................... 14

Vent Pipe Installation ..........................................................................................................15

Pipe Routing & Support....................................................................................................... 15

Location of Outdoor Terminations....................................................................................... 18

Horizontal Venting ............................................................................................................... 19

Vertical Venting ................................................................................................................... 20

Vent Freezing Protection..................................................................................................... 20

Concentric Vent Termination............................................................................................... 20

Drainage of Condensate From Furnace................................................................................. 21

Gas Supply and Piping........................................................................................................ 22

Leak Check.......................................................................................................................... 22

Conversion..................................................................................................................... ...... 23

High Altitude Application ..................................................................................................... 23

Natural Gas High Altitude Conversion ................................................................................ 23

LP/Propane Gas Sea Level and High Altitude Conversion ................................................ 23

Electrical Wiring ........................................................................................................................ 24

Line Voltage Wiring .............................................................................................................24

Low Voltage Wiring ............................................................................................................. 25

Start-up and Adjustments......................................................................................................... 25

Start-Up Procedure..............................................................................................................26

Verifying and Adjusting Firing Rate..................................................................................... 26

Verifying and Adjusting Temperature Rise ......................................................................... 27

Verifying Burner Operation.................................................................................................. 27

Verifying Operation of the Supply Air Limit Switch ............................................................. 29

Description of Components ..................................................................................................... 29

Maintenance ............................................................................................................................... 31

Combustion Air and Vent System ....................................................................................... 31

Air Filter(s) .................................................................................................................. ......... 31

Lubrication ........................................................................................................................... 31

Condensate Drain Assembly............................................................................................... 31

Blower Compartment........................................................................................................... 31

Heat Exchanger and Burner Maintenance.......................................................................... 31

Location of Major Components ........................................................................................... 32

System Operation Information ................................................................................................. 31

Sequence of Operation ....................................................................................................... 33

Furnace Fails to Operate .................................................................................................... 34

Twinning of Two Furnaces .................................................................................................. 34

Installation/Performance Checklist ......................................................................................... 35

4

FURNACE SPECIFICATIONS

Upflow G6RC & G6RD Furnaces

Combustion Air

Inlet

23 1/4"

A

Exhaust Vent

3/4"

3/4"

Figure 1. G6RC, G6RD Unit Dimensions

1 1/2" x 3 1/2" Dia.

43"

15"

1"

22 1/2"

19 3/4"

25 1/8"

Opening for

Gas Connection

7/8" Dia. Electric

Connection

25 1/4"

8"

Return Air Opening

(Side)

Combustion Air
Vent
(See Fig. 15
for sizes)

+

20 1/2"

33"

3/4"

B

C

Return Air Opening

(Bottom)

D

2 1/4"

3/4"

2" PVC
Exhaust
Vent
(See Fig. 15
for sizes)

30 1/4"

25 1/4"

27 5/8"

1 1/2" x 3 1/2" Dia.
Opening for
Gas Connection

7/8" Dia. Electric
Connection

+

8"

25 5/8"

1 1/4"

23"

28"

Condensate Drain Outlets

23"

Bottom Return Opening

Downflow G6RL Furnace

Combustion Air Inlet

24 1/2"

Exhaust Vent

3/4"

22 1/2"

Exhaust

Vent

2"

3/4"

A

B

3/4"

27 7/8"

3/4"

Figure 2. G6RL Unit Dimensions

24 7/8"

7/8" Dia. Electric

43"

1 1/2" x 3 1/2" Dia.

Gas Connection

1"

Connection

21 7/8"

Opening for

21 1/4"

8"

21 1/2"

15 1/2"

Condensate
Drain
Outlet

C

C

L

Bottom Supply Air Opening

(Side)

D

2 1/2"

Combusting

Vent

(3" for 80/100

2" for 40/60)

21 1/2"

Condensate

Drain

Outlet

24 7/8"

7/8" Dia.
Electric

Connection

1 1/2" x 2 1/2"

Knockout

For Gas

Connection

21 7/8"

10 1/4"

19 3/4"

Bottom Opening

5

6

1170

1060

1160

1050

1310

1080

1630

1400

1250

1700

1480

1320

1140

1650

1480

1320

1140

2070

1760

1470

1280

1030

gh*G6RC040C-08

g

G6RC040C-12

gh*G6RC060C-12

gh*G6RC080C-12

gh*G6RC080C-16

Med-High

g

G6RC100C-16

gh*G6RC120C-16

g

G6RC120C-20

Med-High

gh*G6RD040C-10

gh*G6RD060C-10

Model Input Motor Motor

Number (Btuh) Speed HP

Table 1. Furnace Airflow Data

Heating

40,000 Medium 1/5

40,000 Medium 1/3

60,000 Medium 1/3

80,000 Medium 1/3

80,000

100,000 Med-High** 1/2

120,000 Med-High** 1/2

120,000

40,000 Medium 1/3

60,000 Medium** 1/3

Hi

Low**

Hi

h*

Low**

Hi

Low**

Hi

Low**

Hi

Med-Low**

Low

h*

Hi

Med-Low

Low

Hi

Med-Low

Low

h*

Hi

Med-Low**

Low

Hi

Low**

Hi

Low

Ex ternal Static Pressure (Inches W ater Column)

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

CFM Rise CFM Rise CFM Rise CFM Rise CFM Rise CFM Rise CFM Rise CFM Rise

950 36 920 38 890 39 850 41 800 43 750 46 690 50 630 55
740 47 710 49 680 51 650 53 600 58 550 63 490 - 430 -

620 56 590 59 560 62 520 - 470 - 410 - 350 - 290 ­1330 - 1280 - 1230 ­1190 - 1160 - 1110 -

830 42 810 43 780 44 760 46 720 48 670 52 610 57 550 63
1310 - 1260 - 1210 ­1160 45 1120 46 1080 48

800 65 780 67 760 68 740 70 710 73 680 - 650 - 620 ­1490 46 1450 48 1390 50
1230 56 1200 58 1150 60

780 - 750 - 720 - 680 - 630 - 570 - 510 - 440 ­1840 - 1780 - 1700 41
1600 43 1560 44 1470 47

1/2

1380 50 1350 51 1300 53
1100 - 1050 - 1000 - 950 - 900 - 850 - 800 - 750 ­1910 45 1860 47 1780 49
1640 53 1620 53 1540 56
1440 60 1410 61 1370 63
1230 - 1210 - 1180 ­1860 56 1800 58 1730 60
1650 63 1610 65 1550 67
1440 72 1410 74 1380 75
1230 - 1210 - 1180 ­2260 - 2200 - 2140 -

3/4

1870 56 1840 56 1790 58
1540 67 1530 68 1510 69
1360 - 1330 - 1310 ­1050 - 1005 - 960 - 915 - 855 - 800 - 730 48 670 53

990 - 950 - 905 - 860 - 810 - 760 46 700 50 650 54

770 46 740 48 700 50 660 53 625 56 580 61 540 65 500 70
1175 45 1125 47 1075 49
1075 49 1040 51 995 53 950 56 900 59 840 63 790 67 720 73

800 66 770 69 745 71 710 74 670 - 630 - 580 - 530 -

- 1120 - 1030 - 940 37 850 41

- 1010 - 910 38 820 42 720 48

45 1100 47 1040 50 980 53 920 56
49 990 52 940 55 890 58 830 63

53 1210 57 1100 63 980 - 830 ­64 1010 69 910 - 810 - 680 -

42 1550 45 1470 47 1380 50 1290 54
49 1350 51 1280 54 1210 57 1150 60
55 1190 58 1120 62 1040 67 960 -

51 1620 53 1520 57 1420 61 1310 66
58 1420 61 1340 65 1250 69 1150 75
66 1270 68 1210 72 1140 - 1060 -

- 1090 - 1030 - 960 - 880 ­63 1570 66 1480 70 1380 75 1270 82
70 1410 74 1320 79 1230 84 1120 ­79 1280 81 1220 85 1150 - 1080 -

- 1090 - 1030 - 960 - 880 -

- 1990 - 1910 - 1810 57 1710 61
59 1710 61 1660 63 1610 65 1560 67
71 1430 73 1370 76 1300 80 1220 85

- 1250 - 1220 - 1190 - 1150 -

51 970 54 920 57 860 61 800 66

CAPACITIES —Furnace Airflow Data

Heating

g

Med-High

g

g

g

g

g

Med-High

1430

1295

1145

1000

1425

1265

1130

1500

1350

1195

1040

1945

1800

1540

1360

Model Input Motor Motor

Number (Btuh) Speed HP

G6RD080C-14 80,000

G6RD100C-14 100,000 Med-Hi

Table 2. Furnace Airflow Data

G6RD120C-14 120,000 Med-Hi

G6RD120C-19 120,000

G6RL040C-12 40,000 Medium 1/3

G6RL060C-12 60,000 Medium 1/3

G6RL080C-16 80,000 Med-High 1/2

G6RL100C-16 100,000 Med-High** 1/2

Hi

Med-Low**

Hi

Med-Low

Hi

Med-Low

Hi

Med-Low**

High*

Low**

High*

Low**

High*

Med-Low**

High*

Med-Low

h*

Low

h*

Low

h*

Low

h*

Low

Low

Low

1/2

h** 1/2

h** 1/2

3/4

Ex ternal Static Pressure (Inches W ater Column)

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

CFM Rise CFM Rise CFM Rise CFM Rise CFM Rise CFM Rise CFM Rise CFM Rise

1620 - 1560 45 1490 47
1450 49 1400 50 1350 52
1255 56 1225 57 1180 60
1080 65 1055 67 1030 68
1620 54 1555 57 1485 59
1430 62 1375 64 1330 66
1260 70 1220 72 1170 75
1085 - 1050 - 1015 - 970 - 935 - 890 - 850 - 800 ­1700 62 1635 65 1565 67
1510 70 1455 73 1405 75
1330 79 1280 - 1240 ­1140 - 1110 - 1075 ­2140 - 2070 - 2010 ­1955 - 1900 56 1850 57
1660 64 1620 65 1575 67
1450 73 1430 74 1400 75

1280 - 1210 - 1180 - 1140 - 1090 - 1070 - 1030 - 990 ­1140 - 1090 - 1060 - 1030 - 980 35 950 36 910 37 870 39

875 39 835 41 820 41 805 42 780 43 770 44 760 45 750 45
1260 40 1190 43 1155 44 1120 45 1075 47 1030 49 980 52 940 54
1120 45 1070 48 1040 49 1010 50 960 53 930 55 890 57 850 60

855 59 815 62 800 64 780 65 760 67 730 70 710 - 690 ­1635 - 1585 - 1525 - 1460 46 1400 48 1330 51 1260 54 1180 57
1435 47 1395 49 1350 50 1300 52 1255 54 1200 56 1150 59 1090 62
1230 55 1200 56 1165 58 1130 60 1090 62 1050 65 1000 68 960 71
1050 - 1035 - 1010 - 980 - 950 - 910 - 870 - 820 ­1600 53 1555 54 1500 56 1445 59 1380 61 1310 65 1240 68 1160 73
1475 57 1435 59 1385 61 1335 63 1290 66 1240 68 1190 71 1130 75
1320 - 1290 - 1250 - 1215 - 1170 - 1120 - 1070 - 1020 ­1150 - 1130 - 1110 - 1075 - 1040 - 1000 - 950 - 890 -

49 1365 52 1300 54 1240 57 1170 60
54 1240 57 1180 60 1120 63 1060 66
61 1105 64 1060 66 1020 69 980 72
70 960 73 920 - 870 - 820 ­62 1355 65 1290 68 1220 72 1160 ­70 1210 73 1150 - 1080 - 1010 -

- 1070 - 1010 - 950 - 890 -

70 1435 74 1370 77 1310 - 1240 ­78 1290 - 1230 - 1170 - 1100 -

- 1145 - 1100 - 1050 - 1000 -

- 1010 - 980 - 940 - 910 -

- 1870 56 1800 59 1730 61 1650 64
59 1740 61 1690 62 1630 65 1570 67
69 1495 71 1460 72 1410 75 1370 77
78 1340 79 1300 81 1270 83 1230 -

** Factory Set Cooling Speed
** Factory Set Heating Speed

- Not Recommended

NOTES: 1. Airflow rates of 1800 CFM or more require two return air connections. Data is for operation with filter(s).

2. Temperature rises in the table are approximate. Actual temperature rises may vary.

3. Temperature rises and airflows for external static pressures greater than 0.5 are for reference only.
These conditions are not recommended.

7

INSTALLATION REQUIREMENTS

(

)

Requirements and Codes

This furnace must be installed in accordance
with these instructions, all applicable local build­ing codes, and the current revision of the Na­tional Fuel Gas Code (ANSI-Z223.1, NFPA-54).
The current revision of the National Fuel Gas
Code is available from:

American National Standards Institute, Inc.
1430 Broadway

New York, New York 10018
Canada installations shall comply with CAN/
CGA-B149 installation codes, local plumbing or
waste water codes and other applicable codes.
Additional helpful publications are:

• NFPA-90A - Installation of Air Conditioning
and Ventilating Systems.

• NFPA-90B - Warm Air Heating and Air
Conditioning Systems.

These publications are available from:

National Fire Protection Association, Inc.
Batterymarch Park
Quincy, Massachusetts 02269

!

WARNING:

This furnace is not approved for in­stallation in mobile homes. Installa­tion in a mobile home could cause
fire, property damage, and/or personal
injury.

Model

Number

G6R(C,D)040C 40,000 14 1/4 12 3 /4 5 1/8 11 3/ 4 133
G6R(C,D)060C 60,000 14 1/4 12 3 /4 5 1/8 11 3/ 4 140
G6R(C,D)080C 80,000 19 3/4 18 1 /4 7 7/8 17 1/ 4 172
G6R(C,D)100C 100,0 00 19 3/4 1 8 1/ 4 7 7/8 17 1/ 4 180
G6R(C, D)12 0C 120,000 22 1/2 21 9 1/4 20 204

G6RL040C 40,000 14 1/ 4 1 2 3 /4 4 5/8 12 3/ 4 135
G6RL060C 60,000 14 1/ 4 1 2 3 /4 4 5/8 12 3/ 4 135
G6RL080C 80,000 19 3/ 4 1 8 1 /4 10 18 1/4 174
G6RL100C 100,000 19 3/4 1 8 1 /4 10 18 1/4 185

Furnace

Btuh

Table 3. Furnace Dimensions and Shipping Weights

AB

Dimensions (inches)

CD

Shipping

Weight

lbs

CLEARANCES TO COMBUSTIBLE MATERIALS

This furnace is Designed Certified by AGA/CGA Laboratories for the minimum clearances to
combustible material listed in Table 4. See the furnace name plate, located inside the furnace
cabinet, for specific model number and clearance information.

MINIM UM CL EARANCES TO COMBUS TI BLE MATERI AL

Furn ace Cabi net Mi n imu m Cl earan ces (In ch es)

Input Width

(Btuh) (Inches) Side Vent Back Top Front

40, 000 14 1/ 4 0 0 0 1 1*
60, 000 14 1/ 4 0 0 0 1 1*

80, 000 14 1/ 4 0 0 0 1 1*
100,000 19 3/ 4 0 0 0 1 1*
120,000 22 1/ 2 0 0 0 1 1*

* 24 inches is the minimum clearance for servicing.
36 inches is the recommended clearance for service.

Table 4. Minimum Clearances to Combustible Materials

8

Location

The furnace must be installed on a level surface,
and as close to the center of the air distribution
system as possible. See Table 3 for overall
dimensions to determine the required clear­ances in hallways, doorways, stairs, etc. to allow
the furnace to be moved to the installation point.
The furnace must be installed so that all electri­cal components are protected from water.
Minimum clearances to combustible materials
are listed in Table 4. Access for positioning and
servicing must be considered when locating the
unit. 24 inches is the minimum required clear­ance for servicing the unit. 30 inches is the
minimum required clearance for positioning the
unit. 36 inches is the recommended clearance
from the front of the unit. Please note that a
panel or door can be located such that the
minimum clearance on the rating plate is satis­fied, but that panel or door must be removable
and allow the appropriate clearance for your
installation.

This furnace is certified for use on wood flooring.
The furnace must be installed on a solid surface
and must be level front to back and side to side.
This furnace must not be installed directly on
carpeting, tile, or any combustible material other
than wood flooring.

DOWNFLOW WARNING
(G6RL Models):

The design of the downflow furnace is certified
for natural or propane gas and for installation on
non-combustible flooring. A special combus­tible floor sub-base is required when installing
on a combustible floor. Failure to install the sub­base may result in fire, property damage and
personal injury. The special downflow sub-bases
are factory supplied accessories, part numbers
902677 and 902974. When the furnace is in­stalled on a factory or site-built cased air condi­tioning coil, the sub-base is not necessary.
However, the plenum attached to the coil casing
must be installed such that its surfaces are at
least 1" from combustible construction.
A gas-fired furnace installed in a residential
garage must be installed so that the bottom of
the furnace is located a minimum of 15" from the
floor. The furnace must be located or protected
to avoid physical damage by vehicles.

HORIZONTAL INSTALLATIONS

The G6RC model furnaces are approved for
horizontal installation. Installation Kit #903568
is required for horizontal applications. Follow
the installation instructions in the kit for proper
conversion. NOTE: The G6RD and G6RL mod­els are NOT approved for horizontal installation.

SUPPLY AIR PLENUM INSTALLATION

A. Installation on a concrete slab - G6RL

1. Construct a hole in the floor per the
dimensions in Figure 3.

2. Place the plenum and the furnace as
shown in Figure 4.

B. Installation on a combustible floor - G6RL

1. Cut and frame the hole in the floor per
the dimensions in Figure 5.

2. Place the sub-base for combustible floors
over the hole with its duct collar extended
downward. Attach the supply air plenum to
the base in a manner which will ensure 1"
clearance to the flooring or other combustible
material. Place furnace on the combustible
base as shown in Figure 6.

3. When the furnace is installed on a factory
or site-built cased air conditioning coil,
the sub-base is not necessary. However,
the plenum attached to the coil casing
must be installed such that its surfaces
are at least 1" from combustible material.

18.75"

19.25"

Hole in

Floor

G6RL 080/100 G6RL 040/060

Figure 3. Opening for Concrete Slab

13.25"

19.25"

Hole in

Floor

9

Concrete

Furnace

Floor

Sheet

Metal

Plenum

Figure 4. Furnace on a Concrete Slab

18.75"

or 13.25"*

16.75"

or 11.25"*

* Smaller
dimensions for
G6RL 040/060

9.25"

2.0"

28.38"

18.75"

19.63"

Hole in

Floor

G6RL 080/100 G6RL 040/060

Figure 5. Opening in Wood Floor

Downflow

Sub-base

Furnace

13.25"

19.63"

Hole in

Floor

Wood

Floor

Sheet

Metal

Plenum

Figure 6. Furnace on a Wood Floor

CIRCULATING AIR SUPPLY

Plenums and air ducts must be installed in
accordance with the Standard for the Installa­tion of Air Conditioning and Ventilating Systems
(NFPA No. 90A) or the Standard for the Installa­tion of Warm Air Heating and Air Conditioning
Systems (NFPA No. 90B).

1.50"

1.58"

1 inch thick fiberglass 3 lb density

19.75"

or 14.25"*

Figure 7. Downflow Sub-Base Dimensions

If outside air is utilized as return air to the furnace
for ventilation or to improve indoor air quality, the
system must be designed so that the return air to
the furnace is not less than 50°F (10°C) during
heating operation. If a combination of indoor and
outdoor air is used, the ducts and damper system
must be designed so that the return air supply to
the furnace is equal to the return air supply under
normal, indoor return air applications.

When a cooling system is installed which uses
the furnace blower to provide airflow over the
indoor coil, the coil must be installed down­stream (on the outlet side) or in parallel with the
furnace.

If a cooling system is installed in parallel with the
furnace, a damper must be installed to prevent
chilled air from entering the furnace and con­densing on the heat exchanger. If a manually
operated damper is installed, it must be de­signed so that operation of the furnace is pre­vented when the damper is in the cooling posi­tion and operation of the cooling system is
prevented when the damper is in the heating
position.

19.63"

3"

10

!

WARNING:

Products of combustion must not be
allowed to enter the return air ductwork
or the circulating air supply. Failure to
prevent products of combustion from
being circulated into the living space
can create potentially hazardous con­ditions including carbon monoxide
poisoning that could result in per­sonal injury or death.

All return ductwork must be ad­equately sealed, all joints must be
taped, and the ductwork must be
secured to the furnace with sheet metal
screws. When return air is provided
through the bottom of the furnace, the
joint between the furnace and the re­turn air plenum must be sealed.

The floor or platform on which the
furnace is mounted must provide
sound physical support of the furnace
with no gaps, cracks, or sagging be­tween the furnace and the floor or
platform.

Return air and circulating air ductwork
must not be connected to any other
heat producing device such as a fire­place insert, stove, etc.

An important consideration in selecting one or
two pipe installation is the quality of the combus­tion air. Indoor air is sometimes contaminated
with various household chemicals which can
cause severe corrosion in the furnace combus­tion system. Some common sources of these
chemicals are detergents, bleaches, aerosol
sprays, and cleaning solvents. Unless indoor air
is known to be free of these materials, two pipe
installation is recommended.

Provisions must be made for adequate supply of
air for combustion and ventilation. For United
States installations, the adequacy of air provi­sions can be determined by consulting the cur­rent version of the National Fuel Gas Code
(ANSI Z223.1/NPFA-54). For Canadian installa­tions, requirements are specified in the National
Standard of Canada (CAN/CGA B149.1 & .2).
Consult local codes for special requirements.

NOTE: If the furnace is operated without ad­equate air for combustion and ventilation, it may
not perform properly. Furnace components may
be strained by high temperature and could fail
prematurely.

!

WARNING:

Furnace installation using methods
other than those described in the fol­lowing sections must comply with the
National Fuel Gas Code and all appli­cable local codes to provide sufficient
combustion air for the furnace.

Return Air

The return air ductwork may be connected to
any or all of the following: left side return, right
side return, or bottom return. Tables 1 and 2
show the airflow data for each furnace model.

Where maximum airflow is 1800 CFM or
more two openings must be used.

VENTING AND COMBUSTION AIR
REQUIREMENTS

NORDYNE condensing furnaces may be in­stalled with outdoor combustion air piped di­rectly to the furnace, or without such special
piping. Codes refer to the former as "direct vent"
or "two pipe" installation. Installation with air
taken from around the furnace is sometimes
referred to as "one pipe" installation - i.e. only
the vent (exhaust) pipe is provided.

G6RC/G6RD

Protective Screen

G6RL

Figure 8. Protective Screen for One Pipe

Installations

11

80,000

Vent or
Chimney

Each opening must

be at least 100 sq. in.

or 1 sq. in. per 1000

Btuh of total input

rating, whichever is

greater. See minimum

area per table.

12" Max.

Each opening
to outside must
be at least
1 sq. in. per
4000 Btuh of
total input
rating.

-

-

-

-

-

-

12"

-

-

-

Max

Vent or
Chimney

Furnace

Furnace

12" Max.

Water Heater

Minimum

Total Input

Rating (Btuh)

40,000
60,000

Free Area

(Each Opening)

100 sq. in.
100 sq. in.
100 sq. in.

Round Duct

Diameter

12"
12"
12"

Figure 9. Equipment in a Confined Space

with all Combustion Air drawn from Inside

Ventilation Louvers at each end of attic

Vent or
Chimney

Attic
Insulation

Water Heater

Total Input

Rating (Btuh)

40,000
60,000
80,000
100,000
120,000
140,000
160,000

Furnace

Minimum
Free Area

(Each Opening)

10 sq. in.
15 sq. in.
20 sq. in.
25 sq. in.
30 sq. in.
35 sq. in.
40 sq. in.

Air Duct must be
at least 1 sq. in.
per 4,000 Btuh of
total input rating.

Ducts must
extend above
attic insulation.

Air Duct must be
at least 1 sq. in.
per 4,000 Btuh of
total input rating.

12" Max

Round Duct

Diameter

4"
5"
5"
6"
6"
7"
8"

-

-

-

-

-

-

-

-

-

12" Max

Water Heater

Minimum

Total Input

Rating (Btuh)

40,000
60,000
80,000
100,000
120,000
140,000
160,000

Free Area

(Each Opening)

10 sq. in.
15 sq. in.
20 sq. in.
25 sq. in.
30 sq. in.
35 sq. in.
40 sq. in.

Round Duct

Diameter

4"
5"
5"
6"
6"
7"
8"

Figure 10. Equipment in a Confined Space

with all Combustion Air drawn from

Outdoors through Exterior Wall

Vent or
Chimney

Ventilation Louvers
(each end of attic)

---------

Furnace

Alternate

Air Inlet

Outlet
Air

Water
Heater

Inlet Air

---------

---------

Ventilation Louvers For
Unheated Crawl Space

NOTE: Air open­ings shall each
have a free area
of not less than
one square inch
per 4,000 Btuh of
the total input rat­ing of all equipment
in the enclosure.

---------

Figure 11. Equipment in a Confined Space

with all Combustion Air drawn from

Outdoors through Vertical Ducts – from

Ventilated Attic

12

Figure 12. Equipment in a Confined Space

with all Combustion Air drawn from

Outdoors through Ventilated Crawl Space

and Ventilated Attic

Vent or

Chimney

Air Duct
must be
at least
1 sq. in.
per 2000
Btuh of
total input
rating.

Round Duct

Diameter

5"
6"
7"
8"
9"
10"
10"

Total Input

Rating (Btuh)

40,000
60,000
80,000
100,000
120,000
140,000
160,000

Air Duct

Furnace

Air Duct

Water Heater

Minimum

Free Area

(Each Opening)

20 sq. in.
30 sq. in.
40 sq. in.
50 sq. in.
60 sq. in.
70 sq. in.
80 sq. in.

Figure 13. Equipment in a Confined Space

with all Combustion Air Drawn from the

Outside through Horizontal Ducts

Air Requirements For One-Pipe
Installation

When air for combustion is to be taken from
around the furnace, a protective screen must be
installed over the combustion air intake open­ing. This screen is provided with the furnace
installation instructions and functions to prevent
debris from entering the combustion system. It
should be installed on the combustion air intake
collar or inlet PVC. If furnace location is such
that this opening might be unintentionally ob­structed, a 3" PVC elbow should be installed on
the collar, and the screen placed inside the inlet
of the elbow. See Figure 8.

Installation In An Unconfined Space

!

CAUTION:

"Tight" buildings (with weather strip­ping and caulk to reduce infiltration),
may require special provisions for in­troduction of outside air to ensure
satisfactory combustion and venting,
even though the furnace is located in
an unconfined space.

An unconfined space is an area including all
rooms not separated by doors with a volume
greater than 50 cubic feet per 1,000 Btuh of the
combined input rates of all appliances which draw
combustion air from that space. For example, a
space including a water heater rated at 45,000
Btuh and a furnace rated at 75,000 Btuh requires
a volume of 6,000 cubic feet [50 x (45 + 75) =
6,000] to be considered unconfined. If the space
has an 8 foot ceiling, the floor area of the space
must be 750 square feet (6,000 / 8 = 750). In
general, a furnace installed in an unconfined
space will not require outside air for combustion.

!

WARNING:

Furnaces installed with combustion
air drawn from a heated space which
includes exhaust fans, fireplaces, or
other devices that may produce a
negative pressure should be consid­ered confined space installations.

Installation In A Confined Space

A confined space is one which does not meet the
unconfined space volume requirements, and
typically involves installation in a small room. All
such installations must have specific provisions
for introduction of combustion and ventilation
air.

Codes require that two openings be pro­vided for this - one with bottom edge within 12"
of the floor and one with top edge within 12" of
the ceiling.

openings must be per the following sections.
Combustion air openings must not be restricted

in any manner.
Furnaces installed in a confined space which

supply circulating air to areas outside of the
space must draw return air from outside the
space and must have return air ducts tightly
sealed to the furnace.

Air From Inside

Air for combustion and ventilation may be taken
from inside the building through an interior wall

if the building is not "tight" and if the total volume
of the furnace space and the space from which
air is drawn meets the volume requirements for
an unconfined space.

openings in the wall must each have free area of
at least one square inch per 1000 Btuh of
appliance input, but not less than 100 square

The size and other criteria for these

In such cases, the two

total

13

inches of free area. See Figure 9. For example,
if the combined input rate of all appliances is less
than or equal to 100,000 Btuh,
must have a free area of at least 100 square
inches. If the combined input rate of all appli­ances is 120,000 Btuh,
a free area of at least 120 square inches.

Air Directly Through An Exterior Wall

If combustion air is provided directly through an
exterior wall, the two openings must
free area of at least one square inch per 4000

total

Btuh of

appliance input. (See Figure 10.)

each

each

opening

opening must have

each

have

NORDYNE condensing furnaces are classified
as "Category IV" appliances, which require spe­cial venting materials and installation proce­dures. Category IV appliances operate with
positive vent pressure and therefore require
vent systems which are thoroughly sealed. They
also produce combustion condensate, which is
slightly acidic and can cause severe corrosion of
ordinary venting materials. Furnace operation
can be adversely affected by restrictive vent and
combustion air piping. Therefore,

bustion air piping lengths must conform com­pletely to the requirements of Table 5.

vent and com-

Outdoor Air Through Vertical Openings or Ducts

If combustion air is provided through vertical
ducts or openings to attics or crawl spaces, the
two openings must each have free area of at
least one square inch per 4000 Btuh of total
appliance input. Ducts must have cross-sec­tional areas at least as large as the free area of
their respective openings to the furnace space.
Attics or crawl spaces must communicate freely
with the outdoors if they are the source of air for
combustion and ventilation. (See Figures 11
and 12.)

Outdoor Air Through Horizontal
Openings or Ducts

If combustion air is taken from outdoors through
horizontal ducts, the openings must
free area of at least one square inch per 2000
Btuh of total appliance input. Ducts must have
cross-sectional area at least as large as the free
area of their respective openings to the furnace
space. (See Figure 13.)

!

CAUTION:

each

have

Do not supply combustion air from an
attic space that is equipped with power
ventilation or any other device that
may produce a negative pressure.

VENTING REQUIREMENTS

This section specifies installation requirements
for vent and "2-pipe" combustion air piping. For
"one pipe" installations, install vent piping per
this section and provide air for combustion and
ventilation per the previous section. The capac­ity table provided in this section applies to the
total of vent and combustion air piping for either
type of installation.

The furnace must be vented to the outdoors. It
must not be vented in common with any other
appliance, even if that appliance is of the con­densing type. Common venting can result in
severe corrosion of other appliances or their
venting and can allow combustion gases to
escape through such appliances or vents. Do
not vent the furnace to a fireplace chimney or
building chase.

!

WARNING:

FURNACE MUST NOT BE COMMON
VENTED WITH OTHER APPLIANCES.

Vent Pipe Material

Vent and combustion air pipe and fittings must
be one of the following materials and must
conform to the indicated ANSI/ASTM standards:

Material Standard
Schedule 40 PVC D1785
PVC-DWV D2665
SDR-21* D2241
& SDR-26*
ABS-DWV D2661
Schedule 40 ABS F628

Cement and primer must conform to ATSM
Standard D2564 for PVC and Standard D2235
for ABS. When joining PVC piping to ABS, use
PVC solvent cement. (See procedure specified
in ASTM Standard D3138.)

Vent Pipe Length and Diameter

In order for the furnace to operate properly, the
combustion air and vent piping must not be exces­sively restrictive. To ensure this use Table 5, which
indicates the maximum allowable piping length for
a furnace of specified input rate, when installed

14

with piping of selected diameter and number of
elbows. This table applies to the length and num­ber of elbows for each pipe. To use the table, the
furnace input rate, the centerline length and the
number of elbows on each pipe must be known.
Choose the diameter for which the tabulated length
is equal to or greater than required.

Proper use of the table is illustrated by the
following example:

Example:

An 80,000 Btuh furnace is to be installed in a
"one-pipe" system with 40 feet of vent piping.
There are four elbows, including those exterior
to the building.

Solution:

Consulting Table 5, in the single pipe length
column for an 80,000 Btuh furnace, the maxi­mum allowable length of 2" is 60 feet with one
elbow. Select 2-1/2 or 3" pipe. For three addi­tional elbows, deduct 2.5 ft. for each elbow, or

7.5 ft. for a maximum installed vent length of

52.5 ft.

NOTE: Always use the same or larger size
piping for combustion air as is used for the
exhaust vent.

Vent Pipe Installation

Pipe Routing and Support

Route piping as directly as possible between the
furnace and the outdoors and remember that
routing affects pipe size requirements per the
preceding section. If a two pipe system is used,
locate the combustion air intake and the vent
exhaust in the same atmospheric pressure zone

- i.e. both must exit the building though the same
portion of exterior wall or roof. Vent piping must
be sloped upwards not less than 1/4" per foot in
the direction from the furnace to the terminal.
This is to ensure that any condensate flows back
to the furnace (where it can be disposed of
through the condensate disposal system).

The quality of outdoor air must also be consid­ered. Be sure that the combustion air intake is
not located near a source of solvent fumes or
other chemicals which can cause corrosion of
the furnace combustion system.

Condensing furnace combustion products have
very little buoyancy, so Table 5 is to be used
without consideration of any vertical rise in the
piping.

Combustion air must not be drawn

!

CAUTION:

from a corrosive atmosphere.

APPLICATION SINGLE PIPE L ENGTH (f t .) DIRECT VENT, DUAL PIPE LENGTH (ft.)

with 1 long radius el bows* . with 1 l ong radi us el bow s on each pi pe.*

PVC,CPVC or ABS Outlet Outlet Inlet/Outlet Inlet/Outlet Inlet/Outlet

SCH. 40 Pipe Size 2" 3" 2" 2" 3" 2" 3" 3"

Models

G6RC,D,L 80 150 40 40 50 50 90 90

040

Models
G6RC,D,L 60 150 30 30 35 35 90 90
060 & 080

Models
G6RC,D,L 30 150 15 15 25 25 90 90
100 & 120

*NOTES

1. Subtract 2.5 ft. for each additional 2" elbow and 3.5 ft. for each additional 3" elbow.

2. Two 45 degree elbows are equivalent to one 90 degree elbow.

3. One short radius elbow is equivalent to two long radius elbows

4. Do not include termination elbows in calculation of vent length

5. This table is applicable for elevations from sea level to 2000 ft. For higher elevations decrease
vent pipe lengths by 8% per 1000 ft. of altitude.

6. Only the above pipe materials are approved for use with G6 Condensing Furnaces.

Table 5. Vent Table

15

G6RC & G6RD Upflow Furnaces

Exhaust

Inlet

5/8"

Supports at Minimum of 5 ft. Intervals

Combustion
Offset with

Exhaust Pipe
for Adequate
Dimensional
Clearance

PVC or
ABS Pipe

Straight Neoprene Coupling
with 2 Hose Clamps*
(Optional - Not Shown)

G6RL Downflow Furnaces

See Vent T able 4

Straps or Other Suitable

Coupling

Upward Pitch - 1/4" per Foot

Outlet Exhaust Vent

First Support Placed
as Close to Furnace
Connection as Possible

Exhaust Vent

Seal/Caulk
around Pipe
at Building

90˚ Elbow

12" Min.

7"

Wall

Normal Snow Level

Seal/Caulk
around Pipe
at Building

90˚ Elbow

12" Min.

Normal Snow Level

See Vent T able 4

Straps or Other Suitable

Supports at Minimum of 5 ft. Intervals

Coupling

Upward Pitch - 1/4" per Foot

Outlet Exhaust Vent

First Support Placed

Wall

as Close to Furnace

Connection as Possible

Exhaust Vent

Exhaust

Inlet

5/8"

Combustion Air
Inlet

Offset with Exhaust
Pipe for Adequate
Dimensional
Clearance

PVC or
ABS Pipe

Straight Neoprene
Coupling with
2 Hose Clamps

Figure 14. Horizontal Venting

* These couplings are field-supplied and can be used if the installation requires breakable

connections in the piping. Note that a maximum of two couplings per pipe are allowed.

16

G6RC & G6RD Upflow
Furnaces

Support System on

Vertical Rise Below Joints

Support System with

first support as close

to furnace as Possible

5'

Combustion

Air Pipe

Furnace Front

Exhaust

Vent

Straight Neoprene
Couplings with
2 Hose Clamps*
(Optional - Not
Shown)

G6RL Downflow Furnaces

Exhaust

Vent

Combustion

Air Pipe

Cabinet

Support System on

Vertical Rise Below Joints

Support System with

first support as close

to furnace as Possible

Upward Pitch
1/4" per Foot

5'

Straight Neoprene
Rubber Couplings
with 2 Hose Clamps

Cabinet

Furnace Front

Upward Pitch
1/4" per Foot

Figure 15. Vertical Venting

* These couplings are field-supplied and can be used if the installation requires breakable

connections in the piping. Note that a maximum of two couplings per pipe are allowed.

G6RC & G6RD Upflow
Furnaces

Combustion Air Inlet Pipe Collar
Diameter 3" for coupling or reducer

Furnace Top

2" PVC

Exhaust Vent

All Models

G6RL Downflow Furnaces

Combustion Air Inlet
2" PVC on G6RL 040/060 models,
3" PVC on G6RL 080/100 models

Furnace Top

2" PVC
Exhaust Vent
All Models

Figure 16. Furnace Pipe Adaptions

17

Piping must be mechanically supported so that
its weight does not bear on the furnace. Sup­ports must be at intervals no greater than five
feet, and at smaller intervals if necessary to
ensure that there are no sagging sections to trap
water. (See Figures 14 and 15.)

Figure 16 illustrates vent and combustion air
pipe sizes exiting the furnace. Transition to the
correct pipe size must be done close to the
furnace so that the full length of pipe is of proper
size.

Straight neoprene couplings are supplied with
the downflow furnaces only. These couplings
are to be installed in the combustion air inlet (if
present) and exhaust vent piping at the furnace
as shown in Figures 13 and 14. For an upflow
furnace installation, if breakable connections
are required in the combustion air inlet (if present)
and exhaust vent piping, then straight neoprene
couplings for 2” or 3” piping with hose clamps
can be used. These couplings can be ordered
through your local furnace distributor.

To install a coupling, slide the rubber coupling
over the end of the pipe that is attached to the
furnace and secure it with one of the hose
clamps. Then slide the other end of the rubber
coupling onto the other pipe from the vent and
secure the coupling with the second hose clamp.
Ensure that the connection is tight and leak free.

NORDYNE condensing furnaces have been
certified for installation with zero clearance be-

tween vent piping and combustible surfaces.
However, it is good practice to allow space for
convenience in installation and service.

Location of Outdoor Terminations

Vent and combustion air intake terminations
must be located to ensure proper furnace opera­tion and to conform to applicable codes. Figure
16 illustrates necessary distances from the vent
termination to windows and building air intakes.

In Canada, the Canadian Fuel Gas Code
takes precedence over these instructions.
Specifically, all minimum distance require­ments with respect to termination of the vent
piping listed below (items 1 through 8).

The following list is a summary of vent terminal
location requirements:

1. The termination must be 12 inches above
snow level or grade level whichever is higher.
See Figure 18 for alternate method to
achieve 12" above snow level.

2. The minimum distance for a (1-pipe instal­lation) from any door, (openable) window,
or gravity air inlet is 4 ft. below, 4 ft. horizon­tally, or 1 ft. above.

3. The minimum distance for a direct vent (2­pipe) installation) from any door, (openable)
window, or air gravity inlet is 1 ft. below, 1 ft.
horizontally, or 1 ft. above.

4. For one-pipe installations the recommended
minimum distance from an inside corner
formed by two exterior walls is 6 feet, but is
not required.

18

Direct vent
terminal
50,000 Btuh
or less

9 in.

12 in. min

Mechanical
draft vent
terminal

4 ft. min

4 ft. min

12 in. min

Mechanical
draft vent
terminal

12 in. min

12 in. min

12 in. min

Direct vent
terminal ­more than
50,000 Btuh

Figure 17. Vent Termination Clearances

Mechanical
draft vent
terminal

Less

than 10 ft.

3 ft. min.

Grade

Forced
Air Inlet

5. The vent termination for a 1-pipe installa-

g

tion shall be a minimum of 3 ft. above any
forced air inlet within 10 ft.

6. The vent termination shall be located at
least 4 ft. horizontally from any electric
meter, gas meter, regulator and any relief
equipment. These distances apply ONLY to
U.S. installations. In Canada, the Canadian
Fuel Gas Code takes precedence.

7. Avoid areas where condensate drainage
may cause problems by dropping on plant­ers or patios, etc. Also ensure that exhaust
gases will not impinge on windows or build­ing surfaces, which may be compromised
or damaged by condensation. Do not install
the vent terminal such that exhaust is di­rected into window wells, stairwells, under
decks or into alcoves or similar recessed
areas, and do not terminate above any
public walkways.

8. Select the point of wall penetration where
the minimum 1/4 inch per foot of slope up
can be maintained.

Vent Configuration to
Provide 12" Minimum
height above
Snow Level.

Outside
Wall

Pipe
Coupling

Figure 18. Alternate Horizontal Vent

Installation

For horizontal venting, one of the following kits
is recommended:

12" Min.

19" Max.

Support

1/2"
Armaflex
Insulation or
Equivalent

2" PVC 3" PVC

12" Above
Normally
Expected
Snow
Level

!

CAUTION:

For optimum performance, vent fur­nace through wall which experiences
the least exposure to winter winds.

Horizontal Venting

Vent and combustion air intake terminations
must be as shown in Figure 19.

!

WARNING:

Ensure that the combustion air vent
and the exhaust vent are configured as
shown in Figure 19. Improper vent
termination can cause recirculation of
the flue gases. This may result in fur­nace vibration. In severe cases, the
furnace will cycle due to the intermit­tent contact between the flame and the
flame sensor. If you note oscillations
occurring, check the vent configura­tion. Make sure that the exhaust vent
does not have a 90 degree termination.

Through-the-Wall
Exterior Vent
Mountin
Neutralizer Kit - All
Models

For Canadian installations please refer to the
Canadian Installation Code (CAN/CGA-B149.1
or 2) and/or local codes.

The kit consists of two face plates and an
insulating gasket to seal the exterior surface. A
hole sized closely to the pipe diameter must first
be cut through the wall. A short length of pipe is
then cut such that it can penetrate the wall and
be held in place by closely fitting standard cou­plings. The face plates are retained on both
sides of the wall by the couplings, and the gasket
is retained against the wall by the outer face
plate. Face plates must be fastened to the wall
and the outside one must be flashed as appro­priate to prevent entry of water.

When the above kits are not used the following
steps are required:

1. Check the hole size cut through the exterior

2. Extend the vent pipe through the wall ap-

Kit

wall. Insure that the hole diameter is less than
the diameter of the couplings to be used.

proximately 1" and seal the area between
the wall and pipe.

9023730 9023750

9023730 9023730

19

3. Apply couplings to the vent pipe on the
interior and exterior sides of the wall to
insure the pipe can not be pushed or pulled
through the wall.

4. Insure the combustion air inlet pipe (for a 2
pipe installation) has a 90 degree termina­tion elbow as shown in Figures 19 and 20.

b. The top of the chimney is sealed and

weatherproofed.

c. The termination clearances shown in

Figure 20 are maintained.

d. No other gas fired appliances are vented

through the chimney.

Note that a combustion air intake must be
provided with an elbow opening downward.
The screen provided with the furnace must be
installed in the elbow to prevent entry of debris
or creatures.

When the vent pipe must exit an exterior wall
close to the grade or expected snow level, a riser
should be provided as shown in Figure 18.
Insulation is required to prevent freezing of this
section of pipe.

Vertical Venting

Figure 20 shows the proper installation and clear­ances for vertical vent termination. The roof penetra­tion must be properly flashed and waterproofed with
a plumbing roof boot or equivalent flashing. Termi­nation spacing requirements from the roof and from
each other must be per Figure 20.

Vent and combustion air piping may be installed
in an existing chimney which is not in use
provided that:

a. Both the exhaust vent and air intake run

the length of the chimney.

Vent Freezing Protection

When the vent pipe is exposed to temperatures
below freezing, i.e., when it passes through
unheated spaces, chimneys, etc., the pipe must
be insulated with 1/2 inch thick sponge rubber
insulation, Armaflex-type insulation or equiva­lent. Insulating pipe is important to avoid con­densate icing.

For extremely cold climates or for conditions of
short furnace cycles (i.e. set back thermostat
conditions) the last three feet of vent pipe can be
reduced one nominal pipe size provided that the
total vent length is at least 15 feet in length and
the vent is sized in accordance with the venting
requirements (Table 5) before this reduction is
applied. (Example: 3" to 2-1/2" or 2" to 1-1/2")
Smaller vent pipes are less susceptible to freez­ing, but must not be excessively restrictive.

Concentric Vent Termination

A concentric vent termination is approved for
use with these furnaces. The kit part number is

903578. For proper installation of the concentric
vent termination, follow the installation instruc­tions provided with that kit.

20

Exhaust Vent

Option B

Mounting Kit

Faceplate Secured

to Wall with Screws

Combustion

Air Inlet

Exhaust Vent

Option C

7" Min.

18" Min.

36" Max.

18" Min.

36" Max.

8" Min.

18" min.

36" max.

12" Min. to

Normal Snow Level

Inlet

Figure 19. Exhaust and Combustion Air Pipe Clearances

Exhaust Vent

Option A

Grade
Level
or Normal
Snow

Exhaust

Elbow

Combustion

Air

Intake

A= 12" Above Roof or Snow Accumulation Level

Figure 20. Vertical Vent Termination

Exhaust

Vent

1"

18" Min.
36" Max.

A

A

Exhaust

Plumbing Vent Roof Boot
(Typ. Both Pipes)

DRAINAGE OF CONDENSATE
FROM FURNACE

The condensate drainage system is internal to
the furnace. The drain may exit either the right or
left side of the furnace cabinet. For a right side
drain simply extend the tubing out of the 7/8"
hole in the cabinet, see Figure 21.

For a left side drain follow the steps below:

1. Loosen the clamp on the soft exit tube (see
Figure 21.)

2. Rotate the soft exit tube (counter clockwise,
180° upflow G6RC/RD models; clockwise
90° downflow G6RL models.)

A

Collector Box

3. Re-tighten the clamp. MAKE SURE CLAMP
IS TIGHT TO AVOID LEAKAGE OF CON­DENSATE.

4. Route the tubing out of the 7/8" hole located
8 inches up from the bottom furnace.

The condensate should drain from the plastic
collector box (location A in Figure 21) as droplets
or a small stream. If you notice the furnace has
operated for more than 5 minutes without drain­ing or the red status light on the control board is
pulsing a 2-blink code follow the steps below.

1. Remove the collector box soft tube at loca­tion A in Figure 21 and insure the exit from

G6RLG6RC & G6RD

A

Collector Box

Left Side

Drain

8"

"HARD" J
Drain Tube

Left

Rotate counter
clockwise (Step 2)

Clamp
(Loosen For Step 1)
(Retighten for Step 3)

Route to
floor drain.
...OR
Route to
condensate
pump. Keep
downward
slope.

Side
Drain

8"

"HARD" J
Drain Tube

Rotate clockwise

(Step 2)

Clamp
(Loosen For Step 1)
(Retighten for Step 3)

Figure 21. Furnace with Condensate Drain Trap Assembly

Route to
floor drain.
...OR
Route to
condensate
pump. Keep
downward
slope.

21

the collector box is clear of any debris or
obstructions.

2. Replace this tube and insure the fit to the
header spout is air tight. Air will be drawn
into the header if this connection is not tight.

3. Check other tube connections along the
drain system. Insure that all are air tight.

NOTE: Industry research studies indicate that
when condensate is routed to an active drain,
household detergents, etc., buffer its acidity. If
the drain is not actively used or if codes require,
obtain a neutralizer kit (usually contains lime­stone). Proper drains and connections to the
condensate tubing are required as NORDYNE
cannot be held responsible for water leakage
which occurs due to loose hose connections or
improperly sealed drain line pipes.

GAS SUPPLY AND PIPING

This furnace is equipped for either left or right
side gas entry. Typical gas service hook-ups are
shown in Figure 22. When making the gas
connection provide clearance between the gas
supply line and the entry hole in the furnace
casing to avoid unwanted noise and/or damage
to the furnace.

tion must comply with the latest edition of the
National Fuel Gas Code (ANSI Z223.1) or (CAN/
CGA B149) installation codes.

A 1/8" NPT plugged tap must be installed in the
gas line to the unit for use when measuring the
gas supply pressure. The plug should be readily
accessible for service use. A drip leg should be
installed in the vertical pipe run to the unit. Table
5 lists gas flow capacities for standard pipe sizes
as a function of length in typical applications
based on nominal pressure drop in the line.

NOTE: Gas piping must not be run in or
through air ducts, chimneys, gas vents, elevator
shafts, etc.

Compounds used on threaded joints of gas
piping must be resistant to the actions of lique­fied petroleum gases.

The main manual gas valve and main power
disconnect to the furnace must be properly
labeled by the installer in case emergency shut­down is required.

!

CAUTION:

All gas piping must be installed in compliance
with local codes and utility regulations. Some
local regulations require the installation of a
manual main shut-off valve and ground joint
union external to the furnace. The shut-off valve
should be readily accessible for service and/or
emergency use. Consult the local utility or gas
supplier for additional requirements regarding
placement of the manual main gas shut-off. In
the absence of local codes the gas line installa-

Burner Viewport

Denotes field­provided and
installed
components.

Some Utilities

Require Shut-

Off Valv e to

be 4 to 5 feet

Above Floor

Shut-Off Valv e

with 1/8" NPT

Plugged T ap

Roll-Out Limit

Burner
Assembly

Ground
Joint
Union

Automatic Gas Valve

(with manual shut-off)

Do not use matches, lighters, candles,
or other sources of open flame to
check for gas leaks.

Leak Check

After the gas piping to the furnace is complete,
all connections must be tested for gas leaks. To
check for leaks use only a soap and water
solution or other approved method.

Denotes field­provided and
installed
components.

Burner

Assembly

Automatic
Gas Valve
(with manual
shut-off)

Ground Joint
Union

Roll-Out Limit

Some Utilities
Require Shut­Off Valve to
be 4 to 5 feet
Above Floor

Shut-Off Valve
with 1/8" NPT
Plugged Tap

Burner Viewport

22

Figure 22. Typical Gas Service Connection

CAPACITY OF BLA CK IRON G AS PIP E (CU. FT. PER HOUR)

(

)

FOR NATURAL GAS

NOMINAL LENGTH OF PIPE RUN

BLACK IRON (feet)

PIPE DIAMETER

(in.) 1020304050607080

1/2 130 90 75 65 55 50 45 40
3/4 280 190 150 130 115 105 95 90

1 5 20 350 285 245 215 195 180 170
1 1/ 4 1050 730 590 500 440 400 370 350
1 1/ 2 1600 1100 890 760 670 610 560 530

The cubic feet per hour listed in the table above must be greater than the cubic feet per hour of gas
flow required by the furnace. To determine the cubic feet per hour of gas flow required by the
furnace, divide the input rate of the furnace by the heating value of the gas:

SPECIFI C GRAVITY - 0.6 0

Cubic Feet Per Hour Required =

Heating Value of Gas (Btu/Cu. Ft.)

Table 6. Capacity of Black Iron Gas Pipe (cu. ft. per hour)

for Natural Gas (specific gravity = .60)

NOTE: When pressure testing gas supply lines
at pressures greater than 1/2 psig (14 in. water
column), the furnace must be disconnected from
the gas supply piping system to prevent damage
to the gas control valve.

If the test pressure is less than or equal to 1/2
psig (14 in. water column), the furnace must be
isolated from the gas supply line by closing the
manual shut-off valve.

!

WARNING:

This furnace was equipped at the fac­tory for use with natural gas only. A
special kit, supplied by the manufac­turer, is required to convert the fur­nace to operate on LP/propane gas.
Failure to use the proper conversion
kit can cause fire, explosion, property
damage, carbon monoxide poisoning,
personal injury, or death.

Conversion

Conversion of this furnace to use LP/propane
gas must be made by qualified service
personnel, using only approved parts.

High Altitude Application

High altitude application with this furnace can be
field performed by a simple adjustment of
manifold pressure, and if necessary changing
the orifices. The changes required depend on

Input To Furnace (Btu/hr)

the installation altitude and the heating value of
the gas. The gas heating value based on sea
level can be obtained from your local gas utility.
The heating value of gas at high altitude is
always lower than the sea level heating value.
The heating values used in Tables 7 & 8 are
based on sea level values.

Natural Gas High Altitude
Conversion

All factory shipped furnaces are ready to operate
between zero and 4999 ft. above sea level. For
higher altitudes (between 5000 and 10,000 ft.
above sea level), conversion can be achieved
simply by adjusting the furnace manifold pressure

as shown in Table 7.

LP/Propane Gas Sea Level and
High Altitude Conversion

Conversion of this furnace to utilize LP/propane
gas must be made by qualified service personnel,
using factory authorized or approved parts.
Conversion to LP/propane gas can be
accomplished by first replacing the natural gas
orifices with the appropriate LP/propane orifices
shown in Table 9 or 10. Note: for installations
between zero and 5000 ft. above sea level, a
#54 or #55 drill size orifice should be used
depending upon the rated firing rate of the unit
(see Table 9 or 10). However for installations
above 5000 ft. above sea level, a # 55 or #56 drill
size orifice should be used. After changing the
orifices, use Table 8 to determine the appropriate
manifold pressure for your installation.

23

Conversion to LP/propane, sea level, and high

(

)

(

)

(

)

altitude is detailed in the installation instructions
provided with the conversion kit. Approved
conversion kits are listed below.

United States LP/Propane Gas Sea Level and
High Altitude Conversion Kit - P/N 903616

This kit is for LP/propane conversion in the
United States at altitudes between zero and
10,000 ft. above sea level. Follow the installation
instructions supplied with the kit for proper
installation.

Canadian LP/Propane Gas Sea Level and High
Altitude Conversion Kit - P/N 903617

This kit is for LP/propane conversions in Canada
at altitudes between zero and 4500 ft. above sea
level. Follow the installation instructions supplied

with the kit for proper installation.

!

CAUTION:

To avoid electric shock, personal in­jury, or death, turn off the power at the
disconnect or the main service panel
before making any electrical connec­tions.

ELECTRICAL WIRING

Electrical connections must be made in accor­dance with all applicable local codes and ordi­nances, and with the current revision of the
National Electric Code (ANSI/NFPA 70).

For Canadian installations electrical connec­tions and grounding must be done in accor­dance with the current Canadian Electrical Code
(CSA C22.1 Part 1) and/or local codes. If any of
the original wire as supplied with the furnace
must be replaced, it must be replaced with wire
having a minimum temperature rating of 105°C.
Refer to the furnace nameplate and Table 11 for
electrical requirements.

Line Voltage Wiring

The line voltage (115 volt) to the furnace must be
supplied from a dedicated branch circuit con­taining the correct fuse or circuit breaker for the
furnace. See Table 11. An electrical switch
should be readily accessible from and within
sight of the furnace. (See the Wiring Diagram
label in the furnace and Figure 23.)

The furnace cabinet must have an uninterrupted,
unbroken ground to minimize injury should an
electrical fault condition occur. The controls

For a Natural Gas Sea Level Heating Val ue o f 800 to 899 Btu/cu.ft.

Elev at ion

zero to

1999

Ma ni fold Pressure S etti n g ( in WC)

For a Natural Gas Sea Level Heating Val ue o f 900 to 999 Btu/cu.ft.

Ma ni fold Pressure S etti n g ( in WC)

For a Natural Gas Sea Level Heating Valu e of 1,000 to 1,100 Btu/cu.ft.

Ma ni fold Pressure S etti n g ( in WC)

3.5 3.5 3. 5

zero to

1999

3.5 3.5 3. 5

zero to

1999

3.5 3.5

2000 to

4999

Elev at ion

2000 to

4999

Elev at ion

2000 to

4999

fe et above sea l evel

5000 to

5999

fe et above sea l evel

5000 to

5999

fe et above sea l evel

5000 to

5999

3.0 2.8 2. 5

6000 to

7999

3.5 3.0

6000 to

7999

3.2 2.8

6000 to

7999

Table 7. Manifold Pressure (in WC) for Natural Gas at Various Altitudes

Elev at ion (fee t a b o ve sea leve l)

0 to 2,000 to 5,000 to 6,000 to 8,000 to

1,999 4,999 5,999 7, 999 10, 000

Manifold Pressure in (WC)
fo r an LP Gas Heat ing
Valu e of 2,500 Btu/hr.

10.0 8.5 10.0 9.0 8.5

8000 to

10000

8000 to

10000

8000 to

10000

Table 8. Manifold Pressure (in WC) for LP/Propane Gas at Various Altitudes

24

Furn ace Rati ng

g

Plate I n pu t (Btu/ h)

Orifice Drill Size

Nat LP

Furn ace Rati n

Plate I n pu t (Btu/ h)

Orifice Drill Size

Nat LP

45000 44 54
60000 45 55
72000 43 54

96000 43 54
120000 43 54
144000 43 54

Table 9. Natural and LP Gas Orifice Sizes

for Elevations between zero and

4999 ft. Above Sea Level

used in this furnace require an earth ground to
operate properly. Acceptable methods for
grounding are electrical wire or conduit ap­proved for electrical ground service. Do not use
gas piping as an electrical ground.

NOTE: Proper line voltage polarity must be
maintained in order for the control system to
operate correctly. Verify that the incoming
neutral line is connected to the white wire
and the incoming "hot" line is connected to
the black wire in the furnace junction box.
These furnaces will not operate unless po­larity and ground are properly connected.
See Figure 23.

!

CAUTION:

Label all wires prior to disconnection
when servicing controls. Wiring er­rors can cause improper and danger­ous operation. Verify proper opera­tion after servicing.

Low Voltage Wiring

Install the thermostat per the manufacturer's
instructions. The low voltage (24 volt) connec­tions from the thermostat are made at the
terminal strip on the control board in the fur-

Field Supplied
Fused Service

Panel

Black (Hot)

White (Neutral)

Green or Bare

(Ground)

Ground

Field Supplied

Panel Connector

Black
White

Ground

Black

White

45000 44 55
60000 45 56
72000 43 55

96000 43 55
120000 43 55
144000 43 55

Table 10. Natural and LP gas Orifice Sizes

for Elevations between 5000 and 10,000 ft.

Above Sea Level

nace. See Figure 24 for the proper connections
for heating only (two-wire) and heating/cooling
(four-wire) applications. The recommended
minimum wire gauge for thermostat wiring is
shown in Table 11.

The thermostat must not be installed on an
outside wall or any other location where its opera­tion may be adversely affected. Adverse affects
include radiant loading from fireplaces, sunlight,
or lighting fixtures, and convective loading from
warm air registers or electrical appliances.

To check the heat anticipator setting either:

1. Add the current draw of the system compo­nents; or

2. Measure the current flow on the thermostat
R-W circuit after the circulating blower mo­tor has started.

Set the heat anticipator according to the thermo­stat manufacturer's instructions for heat antici­pator settings.

START-UP AND ADJUSTMENTS

Prior to start-up, verify that:

1. The line voltage power leads are securely
connected, that the polarity of the connec­tions is correct, and that the furnace is
properly grounded.

Field Line Voltage

Black
White

Ground

Wiring
Factory Line

Voltage Wiring

Field Supplied Disconnect
Within Sight of Furnace

Figure 23. Line Voltage Field Wiring

25

Furnace Cabinet Nominal Maximum Minimum Maximum Minimum Maximum

Input W i d t h El ect ri c al Op erat ing Operati ng Furnac e Wi re Fuse o r Ci r cu it

(Btuh) (in.) Supply Voltage Voltage Amperes Gauge Breaker Amps*

40,000 14.25 115-60-1 127 103 12.2 14 15
60,000 14.25 115-60-1 127 103 12.2 14 15

80,000 19.75 115-60-1 127 103 14.1 14 15
100,000 19.75 115 -60-1 127 103 14.1 14 15
120,000 22.50 115 -60-1 127 103 17.3 12 20

* Time-delay fuses or HACR-type circuit breakers are required.

Thermostat Recommended Thermostat

Wire Wire Length

Gauge 2-wire 4 or 5-wire

(heating) (cooling)

24 55 ft. 25 ft.
22 90 ft. 45 ft.
20 140 ft. 70 f t .
18 225 ft. 110 ft .

Table 11. Electrical Data

A/C Condensing Unit

Condensing Unit

Control Box

R Y G W

Connect

R & W

For

Heating

Only

Room

Thermostat

NOTE: The "Y"
terminal on the
UTEC control board
must be connected
to the thermostat.

FIELD WIRING

Low Voltage
Connections

R C Y G W

COM

3 Amp

Fuse

24 V

3

6

9

2

5

8

1

4

7

EAC

HUM

Neutrals

Unused Motor Leads

HUM

63
52
41

Blower Off

Flame Signal Light

Status Light

COOL

M1M2M3

Timing

(Yellow)

(Red)

HEAT

EAC

6090120

TWIN

XFMR

L1

Figure 24. Low Voltage Field,

Four-wire Heating/Cooling Applications

2. The thermostat wires (R, W, Y, and G) are
securely connected to the correct leads on
the terminal strip of the circuit board.

3. The gas line service pressure does not
exceed 10.0 in. water column (0.36 psig),
and is not less than 4.5 in. water column
(0.16 psig) for natural gas. For LP gas the
line service pressure must not exceed 14 in.
water column (0.51 psig), and must not be
less than 11.0 in. W.C. (0.40 psig).

4. The roll-out and vent safety manual reset
switches are closed. If necessary, press the
red button to reset a switch. See Figure 28

26

for location. DO NOT install a jumper wire
across a switch to defeat its function. If a
switch reopens on start-up, DO NOT reset
the switch without identifying and correct­ing the fault condition which caused the

180

switch to trip.

5. The blower door is in place, closing the door
switch in the line voltage circuit.

6. The gas line has been purged and all con­nections are leak tight.

Start-Up Procedure

1. Set the thermostat to the lowest setting.

2. Close the disconnect(s) to provide line volt­age to the furnace.

3. Follow the procedures given on the operat­ing instructions label attached to the furnace.

4. Set the thermostat above room tempera­ture and verify the sequence of operation.
(See the SEQUENCE OF OPERATION.)

5. After the furnace has run for approximately
five minutes, set the thermostat below room
temperature and verify steps (9) through
(11) of the SEQUENCE OF OPERATION.

Verifying and Adjusting
Firing Rate

The firing rate must be verified for each installa­tion to prevent over-firing the furnace.

NOTE: The firing rate must not exceed the rate
shown on the furnace rating plate. At altitudes
above 2000 ft. the firing rate must be adjusted as
described in the high altitude section.

Use the following procedure to determine the
firing rate:

1. Shut off all other gas fired appliances.

2. Start the furnace and allow it to run for at
least three minutes.

3. Measure the time (in seconds) required for
the gas meter to complete one revolution.

4. Convert the time per revolution to cubic feet
of gas per hour using Table 12.

5. Multiply the gas flow rate in cubic feet per
hour by the heating value of the gas in Btu
per cubic foot to obtain the firing rate in
Btuh. Example:

• Time for 1 revolution of a gas meter with

a 1 cubic foot dial = 40 seconds.

• From Table 9 read 90 cubic feet per hour

of gas.

• Heating value of the gas (obtained from

gas supplier) = 1040 Btu per cubic foot.

• Firing rate = 1040 x 90 = 93,600 Btuh.

6. Adjustments to the firing rate can be
made by adjusting the gas manifold
pressure. See the High Altitude
Application section for additional
information of firing rate at elevations
above 2000 ft.

The manifold pressure must be set to the appro­priate value for your installation. Refer to either
Table 7 for natural gas or Table 8 for LP/propane
gas to verify the manifold pressure setting re­quired for your particular installation. To adjust
the manifold pressure, remove the regulator cap
and turn the adjusting screw clockwise to in­crease pressure or counterclockwise to reduce
pressure. Replace the regulator cap after adjust­ments are complete.

!

CAUTION:

Do not re-drill the burner orifices. If
the orifice size must be changed, use
only new orifices.

Verifying and Adjusting
Temperature Rise

Verify that the temperature rise through the
furnace is within the range specified on the
furnace rating plate. Temperature rises outside
the specified range could result in premature
heat exchanger failure.

Place thermometers in the return and supply air
stream as close to the furnace as possible. The

thermometer on the supply air side must be
shielded from direct radiation from the heat
exchanger to avoid false readings. Adjust all
registers and duct dampers to the desired posi­tion and run the furnace for fifteen minutes
before taking any temperature readings. The
temperature rise is the difference between the
supply and return air temperatures.

For typical duct systems, the temperature rise
will fall within the range specified on the rating
plate with the blower speed at the factory recom­mended setting. If the temperature rise mea­sured is outside the range specified, it may be
necessary to change the blower speed. Lower
blower speeds will increase the temperature rise
and higher blower speeds will decrease the
temperature rise.

The furnace is equipped with a multispeed mo­tor. Heating and cooling speed selection is made
by moving the leads on the integrated control
board located in the furnace. The wiring diagram
on the furnace and Figures 25, 26 and 27 show
the speed taps for adjusting motor speed.

If it is desired that the blower operate at the
same speed for heating and cooling, tape off the
terminal of the unused blower wire. Install the
jumper wire, found in the plastic instruction bag,
across the HEAT and COOL taps on the control
board. Reconnect the desired blower tap to the
piggyback quick connect.

The blower control is designed to start the
circulating air blower 30 seconds after the gas
valve is opened. The blower control is factory
wired to turn the blower motor off 120 seconds
after the gas valve is closed. This timing can be
changed using the BLOWER OFF timing switch
opposite the terminal block on the control board.
(See Figure 25.)

Verifying Burner Operation

To verify operation of the burners, make sure
that the blower compartment door is in place and
that there is power to the furnace. Set the
thermostat above room temperature and ob­serve the ignition sequence. The flame can be
observed through the small clear window on the
burner box. The burner flame should carry over
between all burners. The flames should be blue,
without yellow tips. Flames should extend from
each burner without lifting, curling, or floating.
After verifying ignition, set the thermostat below
room temperature and verify that the burner
flame extinguishes completely.

27

28

U

TIME FOR

ONE REVOLUTION

(SECONDS) 1 5 10

80 45 225 450
82 44 220 439
84 43 214 429
86 42 209 419
88 41 205 409
90 40 200 400
92 39 196 391
94 38 191 383
96 38 188 375

98 37 184 367
100 36 180 360
102 35 176 353
104 35 173 346
106 34 170 340
108 33 167 333
110 33 164 327
112 32 161 321
114 32 158 316
116 31 155 310
118 31 153 305
120 30 150 300

CUBIC FEET PER REVOL UTI ON OF

METER

TIME FOR

ONE REVOLUTION

(SECONDS) 1 5 10

CUBIC FEET PER REVOL UTI ON OF

METER

24 150 750 1500
26 138 692 1385
28 129 643 1286

Table 12. Gas Flow Rate

30 120 600 1200
32 113 563 1125
34 106 529 1059
36 100 500 1000
38 95 474 947
40 90 450 900
42 86 429 857
44 82 409 818
46 78 391 783
48 75 375 750
50 72 360 720
52 69 346 692
54 67 333 667
56 64 321 643
58 62 310 621
60 60 300 600
62 58 290 581
64 56 281 563

GAS F LOW RATE (C

BIC F EET PER HOUR )

Verifying Operation of the Supply
Air Limit Switch

To verify operation of the supply air limit
switch, make sure that the blower door is in
place and that there is power to the furnace.
Completely block the return airflow to the fur­nace by installing a close-off plate in place of or
upstream of the filter(s). Set the thermostat
above room temperature and verify that the
Sequence of Operation is as described in these
instructions. The supply air limit switch should
function to turn off the gas valve within approxi­mately five minutes. The circulating air and
combustion blowers should continue to run
when the supply air limit switch opens. Remove
the close-off plate immediately after the supply
air limit switch opens. If the furnace operates
for more than five minutes with no return air, set
the thermostat below room temperature, shut
off the power to the furnace, and replace the
supply air limit switch.

Flame Sensor – The flame sensor acts to prove
that flame has carried over from the ignitor to the
opposite end burner. If no flame is sensed, the
furnace will be shut down automatically.

Gas Valve – The gas valve controls the flow of
gas to the burners. When the gas valve is
energized it automatically opens and regulates
the gas pressure in the manifold.

Pressure Switch – The pressure switch verifies
that the inducer is drawing the combustion gases
through the heat exchanger. It also senses a
blocked condensate drain condition.

Vent Pressure Switch (G6RD Only) – The vent
pressure switch reacts to blockage in the vent or
combustion air piping. It is utilized in G6RD
furnaces only.

Supply Air Limit Switch – The supply air limit
switch prevents the air temperature leaving the
furnace from exceeding the maximum outlet air
temperature.

DESCRIPTION OF COMPONENTS

Figure 28 shows the location of each of the
functional components described below. If
any component of the furnace must be re­placed, use only factory authorized replace­ment parts. See the Replacement Parts List
for each component.

Common

Leads

Connect

Neutral

Lead of

Electronic

Air Cleaner

and/or Humidifier

Here.

R C Y G W

EAC

HUM

Humidifier Tap

(.5A@ 120 VAC)

COM

24 V

3

6

9

2

5

8

1

4

7

Neutrals

63

HUM

52
41

Vent Safety Switch – The vent safety switch
shuts the furnace down if the outlet flue gas
temperature increases above 160°F. This switch
protects the plastic flue system and the inducer
from over-temperature conditions.

Flame Roll-Out Switch – This switch provides
flame roll-out protection to the furnace and
combustion air inlet pipe.

90

60

120

3 Amp Fuse

Unused Motor

Leads

M1M2M3

Cooling

Speed Tap

Blower Off

Timing

Flame Signal
Light (Yellow)

Status

Light (Red)

COOL

HEAT

EAC

Heating Speed Tap

180

TWIN

XFMR

L1

Electronic Air Tap

(.5A@ 120 VAC)

Figure 25. Blower Speed Tap Location

29

For G6RC, G6RD and G6RL Residential Furnaces

BLOWER

DECK SWITCH

(SELECT MODELS

ONLY)

BLUE

LIMIT SWITCH

(ALL MODELS)

WHITE (NEUTRAL)

ROOM THERMOSTAT

AIR CONDITIONER
CONDENSING UNIT

FLAME SENSOR

SUPPLY AIR

BLACK 120V

GROUND

R
Y
G

W

GAS

VALVE

C
Y

BLUE

RED

FLAME ROLL-OUT

(ALL MODELS)

YELLOW
BROWN

SWITCH

BLUE

BLUE

BLUE

ORANGE

ORANGE

VENT
SAFETY
SWITCH

(ALL MODELS)

WHITE

GREEN

WHITE W/ BLK STRIPES

BLK W/ WHITE STRIPES

BLACK

TRANSFORMER

24 V

90

60

PRESSURE

SWITCH

BLOWER DOOR
SWITCH

WHITE

120 V

BLACK

180

120

BLACK

VENT
PRESSURE SWITCH
(93+ MODELS ONLY)

3 OR 4 SPEED MOTOR

C

ML

L

H

MH

IGNITOR

Legend

Field Wiring

Factory Wiring:

Low Voltage
High Voltage

FAULT CONDITION
Power On
Limit Circuit Open
Pressure Switch Stuck Open
Pressure Switch Stuck Closed
Ignition Failure (Check Ground)

115 VAC & Neutral Reversed or no Ground

False Flame or Gas Valve Relay Shorted

Power Off

FAULT CONDITION
Low Flame Sensor Signal

Flame Present

R

INDUCER

BLACK

BLACK
BLACK

C

BLACK

STATUS

RED

LIGHT

ON

1 FLASH
2 FLASHES
3 FLASHES
4 FLASHES
5 FLASHES
Continuous

OFF

FLAME

YELLOW

LIGHT

Continuous

Flash

ON

WHITE

RED
ORANGE
BLUE
BLACK

WHITE

1
2
3
4

5

6

MOTOR

PLUG

THESE WIRES ARE

NOT PRESENT

ON 3 SPEED

MODELS

If any of the original wire as supplied with
the furnace must be replaced, it must be
replaced with wiring material having a
temperature rating of at least 105 C.

RED

BLUE

ORANGE

BLACK

Figure 26. G6RC, G6RD and G6RL Integrated Control Board System Diagram

30

MAINTENANCE

It is recommended that the furnace be checked
yearly. At a minimum, this check should include
the following items.

!

WARNING:

To avoid electric shock, personal in­jury, or death, disconnect the electric
power before performing any mainte­nance.

!

WARNING:

Holes in the vent pipe or heat ex­changer can cause products of com­bustion to enter the home. Replace
the vent pipe or heat exchanger if
leaks are found. Failure to prevent
products of combustion from being
circulated into the living space can
create potentially hazardous condi­tions including carbon monoxide poi­soning that could result in personal
injury or death.

Combustion Air and Vent System

Check the combustion air and vent pipe to
ensure that it is not damaged, corroded or
blocked by debris. Any damaged section of vent
pipe must be replaced, and any obstruction or
blockage must be removed prior to operating the
furnace.

Air Filter(s)

The installer should provide a filter rack for a
high velocity type filter in the return air duct
adjacent to the furnace. Filters should be changed
or cleaned monthly during the heating season.
New or newly renovated homes may require
more frequent changing until the construction
dust has been removed.

Lubrication

The bearings in the circulating air blower motors
are pre-lubricated and sealed at the factory. No
further oiling of the bearings is required for the
life of the motor.

Condensate Drain Assembly

Be sure the condensate lines are free and open
(i.e. avoid kinking hoses). Also make sure all
hose clamps are tight to avoid drawing air into
the system.

Blower Compartment

The blower compartment should be cleaned
monthly during the heating and cooling seasons
to remove any dirt and lint that may have accu­mulated in the compartment or on the blower
and motor. Dirt and lint can create excessive
loads on the motor resulting in higher than
normal operating temperatures and shortened
service life.

Heat Exchanger and Burner Maintenance

The furnace should operate for many years
without excessive soot buildup in the flue pas­sageways, however, the flue passageways, the
vent system, and the burners should be in­spected and cleaned (if required) by a qualified
serviceman annually to ensure continued safe
operation. Particular attention must be given to
identify deterioration from corrosion or other
sources.

!

WARNING:

Never operate the furnace without a
filter in place. Dust and lint in the
return air can build up on internal
components, resulting in loss of effi­ciency, equipment damage, and pos­sible fire.

AIR FILTER(S) ARE NOT SUPPLIED WITH THE
FURNACE AS SHIPPED FROM THE FACTORY.
FILTERS FOR SIDE RETURN AND BOTTOM
RETURN APPLICATIONS ARE AVAILABLE
FROM NORDYNE DISTRIBUTORS.

SYSTEM OPERATION
INFORMATION

Proper maintenance is most important to achieve
the best performance from a furnace. Follow
these instructions for years of safe, trouble free
operation.

• Do not place combustible materials on or
against the furnace cabinet or the vent
pipe.

• Do not store gasoline or any other flam­mable vapors and liquids in the vicinity of
the furnace.

31

G6RC & G6RD Upflow Furnaces

1

2

3

4

9

10

11

12

17

19

5
7

8

13

14

15

16

18

1 Ignitor (Not Shown)
2 Flame Sensor (Not

Shown)
3 Gas Valve
4 Flame Roll-out Switch(s)
5 Pressure Switch
6 Vent Pressure Switch

(G6RD Only, Not Shown)
7 Control Board
8 Blower Door

Switch
9 Vent Safety Switch

10 Low Voltage

Transformer

11 Supply Air Limit

Switch

12 Circulating Air

Blower Assembly-

13 Induced Draft

Blower

14 Condensate Drain Tube
15 In-Line Drain

Assembly

16 Burner View Port
17 Front Header Box
18 Combustion Air

Intake

19 Exhaust Vent

G6RL Downflow Furnace

1 Ignitor (Not Shown)
2 Flame Sensor (Not

Shown)
3 Gas Valve
4 Flame Roll-out

Switch(s)
5 Pressure Switch
7 Control Board
8 Blower Door

Switch
9 Vent Safety Switch

10 Low Voltage

Transformer

11 Supply Air Limit

Switch

12 Circulating Air

Blower Assembly-

13 Induced Draft

Blower

14 Condensate Drain

Tube

15 In-Line Drain

Assembly

16 Burner View Port
17 Front Header Box
18 Combustion Air

Intake

19 Exhaust Vent

10

7
8

5

13

9

14

11

3

1
4

19
18

12

15

17

2

16

Figure 28. Location of Major Components

32

• Change or replace the air filters monthly
during any period when the circulating
blower is operating regularly.

• Always replace the doors on the furnace
after servicing. Do not operate the furnace
without all doors and covers in place.

• Avoid operating the furnace when win­dows and doors are open.

• Be sure that the thermostat is properly
installed and is not being affected by drafts
or heat from lamps or other appliances.

Sequence of Operation

Operating sequences for the heating, cooling,
and fan modes are described below. Refer to the
wiring diagrams (Figures 26 and 27) and the low
voltage field wiring diagram (Figure 24).

Heating Mode:

1. On a call for heat the thermostat closes,
applying 24 VAC to the W terminal on the
control board.

2. The control board checks for continuity on
the 24 VAC limit control circuit (over-tem­perature limit switch, flame rollout switches
and blocked vent switch in series). If an
open limit is detected the control board will
energize the inducer and the conditioned
air blower. All other system functions will be
inoperable until the limit circuit closes. While
the limit is open, the red LED will pulse at
a rate of 1 blink per unit time.

3. The furnace control checks for continuity
across the pressure switch (24 VAC). If the
pressure switch is closed the heat mode
sequence will not continue. If it remains
closed for 10 seconds the red LED will blink
3 times repetitively until the fault condition
clears.

4. The inducer is energized.

5. The pressure switch will close. If the pres­sure switch does not close after 10 seconds
the fault LED will blink 2 times repetitively
and the inducer will continue to run until the
switch is closed.

6. The inducer will pre-purge for 30 seconds
and then the ignitor will start its warm-up.
After 30 seconds of ignitor warm-up the gas
valve (24 VAC) will open. The ignitor circuit
stays energized for 6 seconds after the gas
valve opens.

7. The furnace control must prove flame via
the flame sensor six seconds after the gas
valve opens. If flame is sensed, all burners
are on and the ignitor cools off. If no flame
is sensed, the gas valve closes immediately
and the inducer continues to run. A second
trial for ignition (step 6) begins if no flame is
sensed. On the fifth try for ignition, the
furnace control is locked out and the red
LED will blink 4 times repetitively. The ther­mostat must be opened for at least ten
seconds to reset the furnace control after a
lock out. Otherwise, the furnace will attempt
another ignition sequence in 1 hour.

8. The furnace control energizes the circulat­ing air blower on the heating speed 30
seconds after the gas valve circuit is ener­gized .

9. When the thermostat has been satisfied,
gas valve is de-energized.

10. The inducer is de-energized after a 30
second postpurge.

11. The furnace control keeps the circulating air
blower energized for 120 seconds (factory
set) or 60, 90, or 180 seconds (field adjust­able). (See Figure 25.)

12. Abnormal conditions: If a limit opens during
operation, the inducer and circulating air
blower continue to operate. The gas valve is
de-energized immediately. The blowers
continue to operate until the limit closes.
When the limit closes the inducer blower is
de-energized immediately. The circulating
air blower continues to operate for the speci­fied delay (factory set at 120 seconds).

Cooling Mode:

1. On a call for cooling the thermostat closes,
applying 24 VAC to the G and Y terminals
on the furnace control. This closes the
compressor contactor.

2. The furnace control energizes the circulat­ing blower (115 VAC) on the cooling speed.

3. When the thermostat is satisfied, the G
and Y terminals on the control board are
de-energized opening the compressor con­tactor.

4. The circulating air blower is de-energized
after a 90 second delay.

33

Fan Mode:

1. On a call for fan operation, the thermostat
applies 24 VAC to the G terminal on the
furnace control board.

2. The circulating air blower is energized im­mediately on the heating speed.

3. If the furnace is operated in the continuous
ON position at the thermostat and is then
switched to AUTO, the circulating blower
will operate for a specified delay (factory set
at 120 seconds).

Furnace Fails to Operate

If the furnace does not operate check the follow­ing:

1. Is the thermostat operating properly?

2. Are the blower compartment door(s) in
place?

3. Is the furnace disconnect closed?

4. Has the circuit breaker tripped or the control
board fuse burned open?

5. Is the gas turned on?

6. Are any manual reset switches open?

7. Is the filter dirty or plugged?

8. Is the flame sensor coated? (Remove and
clean with emery cloth.)

If the furnace locks out after 5 attempts for
ignition, it will try again every hour if a call for
heat remains. If the inducer and circulating air
blowers are operating, and items 1 through 8
have been checked, press the red reset button
on the vent safety switch. (See Figure 28.) If the
furnace operates after depressing the reset
button, contact a qualified serviceman to identify
and repair the problem.

If the furnace continues to not operate, depress
the red reset buttons on the flame rollout switches.
(See Figure 28.) If the furnace operates after
depressing the reset buttons, contact a qualified
servicemen to identify and repair the problem.

Twinning of Two Furnaces

The control board on these furnaces is capable
of being twinned to another G6 furnace, pro­vided the circuit boards are both UTEC type. If
using UTEC control boards, leave the fuses
installed on each board. The thermostat wires
and the 1/4 inch quick-connect terminals marked
"TWIN" on the furnace controls must be con­nected together for twinning. (See Figure 29.)

Thermostat
W G Y R

A/C
Unit

R
C
Y
G
W

Twin
Terminal

R
C
Y
G
W

Twin
Terminal

Figure 29. Twinning

34

INSTALLATION/PERFORMANCE CHECK LIST

LOCATION __________________________ CITY ____________________ STATE _____
INSTALLER _________________________ CITY ____________________ STATE _____
UNIT MODEL #_______________________ UNIT SERIAL # ________________________

Minimum Clearances per Table 3? ________

Electrical Connections tight?_____________
Line Voltage Polarity correct? ____________
Supply Voltage:___________________ Volts
Blower Motor HP: _____________________
FUEL TYPE:
Natural Gas _______ LP/Propane________
Gas Piping Connections leak-tested?______
Gas Line Pressure: ____________________

(in. water column, with furnace operating)
Manifold Pressure: ____________________

(in. water column, with furnace operating)
Is there adequate fresh air supply for

combustion and ventilation? _____________
Furnace Input: __________________ (Btuh)

Supply Air Temperature: ____________ (° F)
Return Air Temperature: ____________ (° F)
Temperature Rise: ________________ (° F)
Are Flue Connections tight? _____________
Is there Proper Draft? __________________
Is Vent free from restrictions?____________
Is the Filter(s) secured in place?__________
Is the Filter(s) clean? __________________
Has the Thermostat been calibrated?______
Is the Thermostat level? ________________
Is the Heat Anticipator Setting correct? ____
Has the Owner's Information been reviewed

with the home-owner?__________________
Has the Literature Package been left near the

furnace? ____________________________

35

St. Louis, MO

¢707931*¤

707931

7079310 (Replaces 7078950)

Specifications and illustrations subject to change
without notice and without incurring obligations.

Printed in U.S.A. (9/99)