Nordyne M2RC-080 User manual

Direct Vent (Sealed Combustion) Forced Air Gas Furnaces
M2RC Series 90+ Upflow Condensing Furnace
M2RL Series 90+ Downflow Condensing Furnace
Upflow Model
/ 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.
Do not store or use gasoline or
other flammable vapors and
liquids in the vicinity of this or
any other appliance.
Downflow Model
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 aneighbor's phone. Follow
the gas supplier's instructions.
if you cannot reach your gas
supplier, call the fire department.
Extinguish any open flame.
WARNING: Danger. Only qualified service
personnel shall be used to install and provide
maintenance to this appliance.

TABLE OF CONTENTS
General ...................................................... 3
Unit Dimensions ................................. 3
Furnace Airflow Data ......................... 4
Clearances to Combustible Materials 4
Shipping Weights ................................ 4
Owner's Information ............................... 5
Installation Requirements ...................... 5
Location .............................................. 6
Circulating Air Supply ............................ 6
Return Air Provisions .............................. 7
Air Distribution Systems ........................ 7
Upfiow Furnace Installation .................. 8
Downflow Furnace Installation ............. 8
Venting and Combustion
Air Requirements .......................... 11
Venting Requirements .......................... 11
Vent Table ........................................ 12
Vent Pipe Material ............................ 13
Vent Pipe Length and Diameter....., 13 .........
Vent Pipe Installation ........................ 14
Pipe Routing & Support .................... 14
Horizontal Venting ............................ 17
Vertical Venting ................................ 17
Vent Freezing Protection ................. 18
Drainage of Condensate
From Furnace ................................ 18
Gas Supply and Piping ......................... 19
Leak Check ...................................... 20
High Altitude Derate ......................... 20
Conversion ............................................. 21
Lighting and Adjustment
of the Appliance ............................ 23
Electrical Wiring ..................................... 24
Line Voltage Wiring .......................... 24
Low Voltage Wiring .......................... 25
Ventilation ............................................... 26
Start-up and Adjustment ..................... 26
Start-Up Procedure ......................... 26
Shut Down Procedure ..................... 26
Verifying and Adjusting Firing Rate. 26
Verifying and Adjusting
Temperature Rise .......................... 27
Verifying Burner Operation .............. 28
Verifying Operation of the
Supply Air Limit Switch .................. 28
Description of Components ................ 28
Maintenance ........................................... 29
Combustion Air and Vent System ... 29
Air Filter(s) ....................................... 29
Lubdcation ........................................ 29
Condensate Drain Assembly .......... 29
Blower Compartment ....................... 29
Heat Exchanger and Burner
Maintenance .................................. 29
System Operation Information ........... 30
Sequence of Operation .................... 30
Furnace Fails to Operate ................ 31
Furnace Accessories ............................. 31
Location of Major Components._._ '...... 32
Wiring Diagram ...................................... 33
Installation/Performance
Checklist ......................................... 34
M 2 RC.- 080 N
IFuel Type
•I_N - Natural Gas Ready
Application
M-Manufactured Home
Furnace Series,
Comfort Model
RC - Condensing Upflow
RL -Condensing Downflow
L-Propane (LP) Gas Read_
Cabinet Width
--B - 19-3/4"
Airflow
16 - 1600 CFM
Electrical Code
A-1PH, 60 Hz, 120 VAC
Heating Capacity
Input, BTUH (000')
Table 1. Model Identification
2

GENERAL
Upflow Furnace
Cover
Plate
Combusbon Air
Inlet J_l Combustion
23 1'4" -- Airln_et --
L/
1 3/8"
2 t,4" Condensate
4-- Drain Outlet
6 114"
_.: rt
r7
9 n
Bottom Ream
Opening
-- 19 314"_
Exhaust
Vent
A/C Coil Box
--27 5,8"
Gas Connection
Condensata
Drain Outlet
Downflow Furnace
i
Combust;cm Air Inlet I
i
'_ i I Exhaul_ ,.
_,-_ : -_,
i
2
_l_ 24 718"
1 I/2" T
21 114"_ t5t/2.
°+,,,,o. 1111llt@
,(-_ 19 3/4" _1
Norton Supply Air O_0emng
10_
k_ 8UpldyAk
O_nm.g
(S_ I
Sl/4'
Bottom Supply Atr Open nt
I-3/4-
Combustion
Air Inlet
RetumAirOpenln
-- 27 718"--
, Y
718" Die
Electric
Connection
"_" 11/2. x2 tl2 .
?
21 1/2"
Figure 1. Unit Dimensions 3

IMPORTANT:READALL INSTRUCTIONS
CAREFULLYBEFOREBEGINNINGTHE
INSTALLATION.
/ WARNING:
Do not use this product if any part has
been submerged under water.
Immediately call a qualified service
technician to inspect the appliance and
to replace any part of the control system
and any gas control that has been
submerged under water.
ifiedservice technician periodically check allwiring
connections and service unit as required.
The M2 sedes gas furnaces are listed drect vent
(sealed combustion) forced air furnaces (type
FSP) for use with both natural and propane (LP)
gases. The M2 furnace series has been certi-
fied tothe UL 307B standard for use in the United
States and to ANSI Z21.47a-CAN/CGA-2.3a-
1995 for use in the United States and Canada.
These furnaces may be installed in:
1. Manufactured Homes
2, Recreational Vehicles, Park Models
3. Manufactured Buildings
/ WARNING:
Should overheating occur, or the gas
fail to shut off, shut offthe manual gas
valve to the appliance before shutting
off the electrical supply.
NOTICE: Leave these instructions withthe home-
owner. Advise unit owner/user to follow the main-
_ter]ance rrecommendations outlined. Have a qual-
4. Modular Homes /Buildings
The M2 furnace is not to be used for the tempo-
rary heating of buildings under construction.
Model Shipping Weight (Ibs)
M2RC - 080A * 16 -B_*) 160
M2RC -1OOA-16 -S(*) 170
M2RL - O60A-16 -B(*) 170
M2RL - 080A -16 - B(*) 170
M2RL -100A - 16 -B(*) 175
A]C Coil Box 20
•Can be N orL
Table 2. Shipping Weights
CAPACITIES --Furnace Airflow Data
Furnace
Furnace input Motor _oto; 0.t
Model No. B_uh Speed HP CFM Rise
High * 1840 *
M2RO-OSO 80,000 Meal-High 1/2 1600 43
Med-Lcw *' 1380 50
Low 1100
High * 1910 -
M2RC-100 100,000 Meal-High "1640 53
Med-Low 1/2 1440 61
Low 1230 -
High * 1620 32
Med High 1450 36
M2RL_60 60,000 Med Low *' 1/2 1255 42
Low 1080 48
High" 1620 43
Med High 1450 49
M2R L-089 8_,000 Med Low _1/2 1255 56
L_ 1080 65
High* 1620 54
Meal High " 1430 62
M2RL-100 100,000 Med Low 112 1260 70
Low 1085
•Factorywired cc_ling speed tap
•* Factory wired heatingspeed tap
Exkrnal stage Pr,_sure (Inches Water Column}
0.2 0.3 0.4 0.5
CFM I_se CFM Rise CFM Rise CFM Rise
1780 -1700 -1630 -1550 -
1560 44 1470 47 1400 49 1350 51
1350 51 1300 53 1250 55 1190 58
1050 1000 950 900
1860 - 1780 - 1700 - 1620 -
1620 54 1540 57 1480 59 1420 62
1410 62 1370 64 1320 66 1270 70
1210 -1180 - 1140 . 1090 -
1560 33 1490 35 1430 36 1365 38
1400 37 1350 38 1295 40 1240 42
1225 43 1180 44 1145 45 1105 47
1055 49 1030 51 1000 52 960 54
1560 45 1490 47 1430 49 1365 52
1400 50 1350 52 1295 54 1240 57
1225 57 1180 60 1145 61 1105 64
1055 67 1030 68 1000 70 960 73
1555 57 1485 59 1425 62 1355 65
1375 64 1330 66 1265 70 1210 73
1220 72 1170 75 1130 1070
1050 1015 970 935
-NotRecommended
Table 3. NOTE:Dataisforoperationwfthfilter.
Furnace Airflow Data
CLEARANCES TO COMBUSTIBLE MATERIALS
Thisfurnace is designedfor the minimum clearancesto combustiblematerial listed in Table 4. Refer
tothe fumace name plate, locatedinside thefurnacecabinet,for specificmodel numberand clearance
information. Furnace Cabinet Minimum Clearances (Inches}
Input Width Plenum Ductwork within
(Stuh} flnches_ Side Vent Back Top* Front** Surfac_ 3 fL of Furnace
60,000 19314 O O0 10 0 1/4 1/4
80,000 193/4 O O O 10 O1/4 1/4
100,000 193/4 0 O0 19 0 1/4 , 1/4
* For Downflow model only.Upflow modelscan be 1".
** 24 inches isthe minimum clearance for servicing. 36 inches is the recommended clearance for service.
Table 4. Minimum Clearances to Combustible Materials
4

NOTICE TO INSTALLER
Installer is advised to follow carefully all in-
structions and warnings in this manual to in-
sure maximum performance, safety, and oper-
ating efficiency of these appliances. Improper
installation may create hazardous conditions,
and will void the appliance warranty.
Manufacturer Warranty, Owner's
Responsibilities
It isthe sole responsibility of the homeowner to
make certain the gas furnace has been cor-
rectly installed in the home, converted to the
proper fuel (LP gas or Natural gas), and ad-
justed for proper operation.
OWNER'S INFORMATION
About Your Central Furnace System
NORDYNE has been involved in the design of
products for the manufactured home industry
since the first manufactured home or trailer
was built.
NORDYNE originated the sealed combustion
system, which separates the furnace com-
bustion system from the living area of the home
and is now a standard for the manufactured
home industry.
NORDYNE engineers developed the first cen-
tral heating system and the first central air
conditioner for manufactured homes.
NORDYNE is dedicated to bringing to its cus-
tomers the finest heating and cooling comfort
possible. NORDYNE constantly seeks to fur-
ther refine its products to continuously provide
exceptional comfort.
Awarranty certificate with full details is in-
cluded with this furnace. However, NORDYNE
will not be responsible for any costs found
necessary to correct problems due to im-
proper setup, improper installation, furnace
adjustments, improper operating procedure
on the part of the user, etc.
Some specific examples of service calls which
cannot be included in warranty payments are:
1. Converting the furnace to use another
type of gas.
2. Repairing duct work in the home found to
be faulty.
3. Correcting wiring problems in the electri-
cal circuit supplying the furnace.
4. Resetting circuit breakers, blown fuses
or other switches.
5. Correcting problems due to improper gas
supply pressure to the furnace.
6. Providing instructional training on how to
light and operate the furnace.
7. Correcting any problems caused by in-
stallation of an air conditioner, heat pump
or other air comfort devices.
Follow the instructions in this booklet carefully 8. Revising installation of the furnace flue
and this appliance will provide many years _of ......... assembly: ..............................
superior performance. 9. Adjusting or calibrating of thermostat.
Ifyou wish to cool your home automatically with
a central air conditioning system investigate
the excellent NORDYNE cooling systems avail-
able from your heating and cooling contractor.
These systems are designed to work best with
your NORDYNE furnace and have been care-
fully engineered to deliver optimal performance
when mated with NORDYNE manufactured
home furnaces.
NORDYNE also offers water heaters, fire-
places and ventilating systems specifically
designed for manufactured housing applica-
tions. Ask your manufactured home retailer,
10. Removing any construction debris which-
has fallen into flue system.
Carefully review these responsibilities with
your manufactured housing dealer, service
company, or gas supplier, so that there will be
no misunderstanding at a later time.
INSTALLATION REQUIREMENTS
Requirements and Codes:
The installer must be familiar with and comply
with all local codes and regulations applicable
to the installation of heating appliances and
related equipment. In the absence of local
your heat nn and coolin,_ contractor or your codes, the installationmust conform with these
distributor for more information. Write directly instructions and the current provisierfs_'6f_one
to the factory (PO Box 46911, St. Louis, MO or more of the following standards:
63146) if you are unable to locate a source for a. Federal Manufactured Home
NORDYNE manufactured housing products in Constructions & Safety Standard (H.U.D.
your area. Title 24, Part 3280.707[a][2])

b. TheStandardfor ManufacturedHome
Installations (Manufactured Home Sites,
Communities, and Set-Ups)ANSI A225.1
and/or CAN/CSA-2240 MH Series).
c. American National Standard (ANSI-
119.2/NFPA-501C) for all recreational
vehicle installations.
d. American National Standard (ANSI-
Z223.1/NFPA-54) and/or CAN/CGA
B149 for all gas-fired furnace models.
e. American National Standard (ANSI-C1/
NFPA-70) and/or CSA 22.1 Canadian
Electric Code Part 1 for all electrical field
wiring.
CE g6nerateur d'air chaud dolt 6tre insta]l_
conform6ment aux instructions du fabricant et
aux codes Iocaux. En I'absence de code local,
respecter la norme ANSI Z223.,1, institule Na-
tional Fuel Gas Code ou les codes d'installation
CAN/GCA-B 149.
The National Fuel Gas Code is available by
writing:
able 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 models can only be installed on
combustible flooring when installed on a
Nordyne plenum base (part numbers 901987
through 901993 - see Table 5). Both the upflow
and downflow models must be installed with
the Nordyne A,'C coil box (part no. 914958).
The plenum attached to the A,'C coil box and
the ductwork within 3 feet of the furnace must
be installed such that surfaces are at least
1/4" from combustible construction.
CIRCULATING AIRSUPPLY
General
Plenums and air ducts must be installed in
AmericanNationaIStandardslnstitute,lnc. 'accordance with the Standard for the
1430 Broadway Installati0n of Air Conditioning and Ventilating
New York, NY 10018 Systems (NFPA No. 90A) or the Standard for
the Installation of Warm Air Heating and Air
NFPA publications are available by writing: Conditioning Systems (NFPA No. 90B).
National Fire Protection Association
Batterymarch Park
Quincy, ME 02269
Location
The furnace must be installed on a level sur-
face, and as close to the center of the air
distribution system as possible. See Figure 1
for overall dimensions to determine the re-
quired 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 isthe
minimum required clearance for positioning the
unit. 36 inches is the recommended clear-
ance 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 remov-
/ WARNING:
Products of combustion must not be
allowed to enter the return air openings
of the furnace or the circulating airsupply,
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.
The floor or platform on which the fumace
is mounted must provide sound physical
support of the furnace with no gaps,
cracks, or sagging between the furnace
and the floor or platform.
The circulating air ductwork must not be
connected to any other heat producing
device such as a fireplace insert, stove,
etc.

RETURN AIR PROVISIONS
Upfiow models draw the return air from the
base of the furnace. A stand or return air duct
must be supplied to the furnace to provide the
required return air.
Downflow models draw the return air from the
top of the furnace. The minimum required
clearance to the top of the furnace is detailed
on the furnace rating plate. Additional clear-
ance may be required depending upon filter
accessibility.
For each application, the U.S.A. home manufac-
turer shall comply with all of the following condi-
tions to have acceptable retum air systems for
closet installed forced air heating appliances:
a. Regardless of the location, the return air
opening into the closet shall not be less
than specified in the appliance's listing.
b. Means shall be provided to prevent
inadvertent closure by a flat object placed
over the return air opening when it is
located in the floor of the closet (versus
the vertical front or side wall).
c. The cross-sectional area of the return
duct system leading into the closet shall
not be less than 390 square inches.
d. The total free area of openings in the floor
or ceiling registers serving the return air
duct system must be at least 352 sq. in.
At least one register should be located
where it is not likely to be covered by
For floor return systems, the
manufactured home manufacturer shall
affix a prominent marking on or near the
appliance where it can be easily read
when the closet door is open. The
marking shall read:
CAUTION:
HAZARD OF ASPHYXIATION: Do not
cover or restrict return air opening.
k. Air conditioning systems may require
more duct, register and open louver area
to obtain necessary airflow. Use
NORDYNE's certiduct program to
determine proper duct size for A/C.
AIR DISTRIBUTION SYSTEMS
For proper air distribution, the supply duct
system must be designed so that the static
pressure measured external to the furnace
does not exceed the listed static pressure
rating shown on the furnace rating plate.
Three typical distribution systems are illustrated
in Figure 2. Location, size, and number of
registers should be selected on the basis of
best air distribution and floor plan of the home.
A Single trunk duct []
carpeting, boxes and other objects ............................................................
e. Materials located in the return duct
system must have a flame spread
classification of 200 or less. This includes
a-closetdo0r if theefu-rnac_ is"fna-cios_t._
f. Noncombustible panshaving 1"upturned
flanges are located beneath openings in
afloor duct system.
g. Wiring materials located in the return
duct,system shall conform_to Articles ,-
300-22 of the National Electrical Code
(ANSI CI/NFPA-70).
h. Gas piping is not run in or through the
return duct system.
i. Test the negative pressure in the closet
with the air-circulating fan operating at
high speed and the closet closed. The
negative pressure is to be no more
negative than minus 0.05 inch water
column.
BJ Dual trunk duct _ ]
- _ wlcrossover connector-_- •
J
U U U
Figure 2. Typical Supply Duct System
FLOOR CAVITY
U(depth equal to "X* in F3gure 5 and Table 5)
tJJJJJJJJJJJJJJJJJJJJJ JJ _JJi_
x-l--- -----.._ il ,l
II)J SuPPLYAiRoucT
-- I_! /k h\l
Figure 3. Floor Cavity Cut-Out 7

If "X"
(Floor cavity) is:
7/8" (22ram)
2" (51ram)
4 1/4" (108ram)
6 1/4" (159rnm)
8 1/4" (210mm)
10 1/4" (260ram)
12 1/4" (311mm)
Use Duct
Connector Model
901987
901988
901989
901990
901991
901992
901993
Table 5. Duct Connectors
1-10li,,
, 1
Figure 4. Top View of Duct Connector
OPENING TO DUCT
WITH pLATE {C) REMOVED
13-1/4" x 13-1/4"
OPENING BECOMES
Figure 5. Duct Connector
UPFLOWFURNACE
INSTALLATION
a. Position the furnace on top of the return
air ductwork or return air stand. NOTE:
The ductwork or stand must have an
opening equal to that of the return air
opening of the furnace. Refer to Figure 1
for the proper return air opening size.
Secure the furnace to the floor or base
once it has been properly positioned.
b. Position and secure the A/C coil box to
the top of the furnace. The A/C coil box
C.
d.
can be secured to the furnace using the
provided attachment brackets. These
brackets are designed to attach the
furnace cabinet to the A/C coil box on the
sides. To install these brackets, position
one bracket on the side of the furnace,
so that the locating dimples are in the
groove created by the top of the furnace
cabinet and the bottom of the A/C coil
box. Using the provided self-drilling
screws, secure the bracket to the A/C
coil box and the furnace. Repeat on the
other side of the furnace for the other
bracket.
Attach the plenum from the supply duct
to the flanges of the A/C coil box.
Secure the plenum to the supply
ductwork.
NOTE: Additional fasteners may be used
at rear, sides or through door frame, as
desired, to secure furnace to closet or
alcove framing.
DOWNFLOWFURNACE
INSTALLATION
DUCT CONNECTOR SELECTION FOR
DOWNFLOW MODELS
a. Determine depth of floor cavity from
surface of floor to top of supply air duct
(See Figure 3).
b. Select appropriate model from Table 5
which matches X-dimension of the floor
cavity. To maximize air delivery, remove
reducer "C" (see Figure 5) to obtain the
largest open area that will fit the duct/
floor construction.
INSTALLATION OF THE DUCT CONNEC-
TOR FOR DOWNFLOW INSTALLATIONS
Required cut-out openings in the floor, ceiling,
roof, and/or walls must be carefully located to
avoid misalignment ofthe furnace, combustion
air piping,and vent piping (see Figures 14-16).
Installation procedures are suggested for
typical furnace installations and need not be
followed in the exact listed sequence.
CUT OUT FLOOR OPENING FOR
DOWNFLOW MODELS
a. Determine center of closet or alcove
(Figure 7).
b. Locate center ofthe floor opening, mea-
sured 10" from the rear wall, and mark
cut-out measuring approximately 14-1/
2" by 14-1/2" (+ 1") for model duct
connector used (refer to Figures 6 & 7).

Figure 6. Cut-Out Locations
HOLE
Figure 7. Closet or Alcove Floor Cut-Out
MOUNTING
PLATE REAR WALL fFUEL
1/16TH. LARGER THAN
DUCT CONNECTOR
Figure 8, Mounting Plate
BEND CONNECTOR TABS
UNDER DUCT OPENING
MOUNTING
PLATE
FLOOR
CUTDUCTOPENING
a. Place duct connectorthroughthe floor
b.
Figure 9. Duct Connector
opening with bottom tabs resting on
top of the supply air duct.
Center duct connector and push back
against rear edge of floor opening.
c. Mark cut-out location (tab area) and
remove duct connector.
d. Cut out duct opening 1/4" larger than
area marked. 9

TABS TABS
-- DUCT _DUCT
1. INSERT DUCT PLENUM CONNECTOR
INTO DUCT CUT-OUT. 2. BEND Bo'n'OM TABS OVER
AND ONTO THE UNDERNEATH
DUCTSER_CE.
Figure 10. Installation of Duct Connector
INSTALL FURNACE MOUNTING PLATE
a. Bend tabs on furnace mounting plate
upwards 90°
b. Place mounting plate (supplied within
duct connector) at rear of the floor
opening (See Figure 8).
INSTALL DUCT CONNECTOR
e. Place duct connector through the floor
opening with bottom tabs extending
through the duct opening. (See Figure 9)
b. Secure duct connector to floor.
c. Bend bottom tabs under and up tightly
against the supply air duct (See Figure
10).
NOTE: The duct connector is designed for
use on ducts 12" in width. When using the
connector on 12" wide ducts, there may be
insufficient clearance to bend the tabs on two
sides of the duct connector. In such cases the
tabs may be attached to the sides of the duct
by using sheet metal screws or other suitable
fasteners. (See Figure 11).
if ial_e is used to provide a better seal, it should
be approved byapplicable national orlocal codes.
ALTERNATE ATTACHMENT METHODS
This procedure may also be used to install a
furnace duct connector to narrow metal
ductworkwhere insufficientclearance prevents
bending of the duct connector tabs at the
side(s) of the duct. (See Figure 12).
1. Score and cutthe topof the metal duct as
indicated in Step 1 or Step 2. With Step 1
choice, also cut out the metal from the
shaded area "A".
2. Fold the duct flap "B" up, (See Step 3).
3. At the front-to-back of duct run (Area
"A"), bend the duct tabs and secure them
directly to the duct.
DuctConnector "--_
I
Duct fNa_ow
Figure 11. Narrow Duct Installation
Duct
STEP 1. STEP 2,
Fold Back Flap "B" Cut Fold _Rap'B"
"' _a "O_A" "B" I
_Fold Back Rap "B. _-- Fold Back Flap'B"
Bend DUCt Connector Tabs Up
and Over- (alonglengthof duct)
Stapk_ Folded Duct
Flap (lypl _0,_ide of Du_
Connector
Duct
STEP 3. S1]EP 4.
Figure 12. Alternate Installation
10

4. At area"B",bendtheducttabsupand
backover,aroundtheduct connector,
(SeeStep3).
5. Fold/formtheductflapagainstthesideof
theductconnectorand attach as shown,
(See Step 4). Use three (3) staples
(minimum) on each duct flap OR, if a 2X
block/joist is not provided, use two (2)
sheet metal screws (minimum) on each
duct flap. An alternate attachment method
is acceptable, as long as the plenum is
securely attached.
6. Tape the duct flap edges with an approved
tape for a leak-free joint.
INSTALL DOWNFLOW FURNACE
a. Prepare the NC coil box as described in
the instructionsprovidedwith the coil box.
b. Place A/C coil box onto duct connector.
c. Slide A/C coil box back until it is firmly
against the mounting plate. Mounting
plate tabs should be bent upwards so as
not to interfere with furnace.
d. Secure front with one (1) fastener at
each corner through front bottom flange
and through the back ofthe A/C coilbox.
e. Positionthe furnace ontop ofthe A/C coil
box. Ensure that the furnace is properly
positioned on the wrapper.
f. Secure the A/C coil box to the bottom of
the furnace. The A/C coil box can be
secured to the furnace using the provided
attachment brackets. These brackets
are designed to attach the furnace
cabinet to the AJC coil box on the sides.
To install these brackets, position one
bracket on the side of the furnace, so that
the locating dimples are in the groove
created by the bottom of the furnace
cabinet and the top of the A/C coil box.
Using the provided self-drilling screws,
secure the bracket to the A/C coil box
and to the furnace. Repeat on the other
side of the furnace for the other bracket.
NOTE: Additional fasteners may be used at
rear, sides or through door frame, as desired,
to secure furnace to closet or alcove framing.
VENTING AND COMBUSTION AIR
REQUIREMENTS
CAUTION:
Snow must not be allowed to restrict or
block the combustion air intake or vent
pipes.
General
NORDYNE condensing furnaces must be
installed with outdoor combustion air piped
directly to the furnace, Codes refer to this type
of installation as direct vent, or two pipe
installation.
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:
The combustion air piping must not be
blocked or restricted in any manner,
z WARNING:
Fumace 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 fumace,
VENTING REQUIREMENTS
/t',WARNING:
FURNACE MUST NOT BE COMMON
VENTED WITH OTHER APPLIANCES.
General
This sectionspecifies installation requirements
for 2-pipe combustion air piping. The capacity
table provided in this section applies to the total
sum of vent and combustion air piping lengths.
11

Thesecondensing 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, vent and combustion air piping
lengths must conform completely to the
requirements of Table 6.
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 afireplace chimney or
building chase.
If removing an existing furnace in a venting
system, the venting system may not be propedy
sized. To test the vent system with'-the
remaining appliances, follow the test outlined
below.
The following steps shall be followed with each
appliance connected to the venting system place
in operation, while any other appliances con-
nected to the venting system are not in operation:
a. Seal any unused openings in the venting
system.
b. Inspect the venting system for proper
size and horizontal pitch, as required in
the National Fuel Gas Code, ANSI Z223.1
orthe CAN/CGA B149 Installation Codes
and these instructions. Determine that
there is no blockage or restriction,
leakage, corrosion and other deficiencies
which could cause an unsafe condition.
c. In so far as is practical, close all building
doors and windows and all doors between
the space in which the appliance(s)
connected to the venting system are
located and other spaces of the building.
Turn on clothes dryers and any other
appliance not connected to the venting
system. Turn on any exhaust fans, such
as range hoods and bathroom exhausts,
so they shall operate at maximum speed.
Do not operate a summer exhaust fan.
Close fireplace dampers.
d. Follow the lighting instructions. Place
the appliance being inspected in
operation. Adjust thermostat so appliance
shall operate continuously.
e. Test for draft hood equipped appliance
spillage at the draft hood relief opening
after 5 minutes of main burner operation.
Use the flame of a match or candle.
f. After it has been determined that each
appliance connected to the venting
system properly vents when tested as
outlined above, return doors, windows,
exhaust fans, fireplace dampers and
any other gas burning appliance to their
previous conditions of use.
APPLICATION
PVC, CPVC or ABS
SCH. 40 Pipe Size
Model M2RL 060
Model M2RCIL 080
Model M2RC/L 100
DIRECT VENT, DUAL PIPE LENGTH (ft.)
with 1 long radius elbow on each pipe.*
Inlet/Outlet
3==
50
90
90
3 ID
5O
9O
9O
*NOTES
1. Subtract 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 these condensing furnaces.
Table 6. Vent Table
12

g. If improperventingis observedduring
any of the abovetests, the venting
systemmustbe corrected.
Proc6dercommesuitpourchaqueappareil
raccord6ala tuyauterie d'_vacuation et en _tat
normal de fonctionnement; tous les autres
appareils raccordes & la meme tuyautede
d'_vacuation doivent _tre mis hors service:
a. sceller toute ouverture non utilis6e de la
tuyauterie d'evacuation
b. s'assurer que la tuyautede d'6vacuation
pr6sente des dimensions et une pente
horizontale conformes & la norme ANSI
Z223.1, intitul_e National Fuel Gas Code
ou aux codes d'installetion CAN/CGA
B149, ainsi qu'aux pr_sentes
instructions. S'assurer que la tuyauterie
n'est pas bloqu6e, restreinte, corrodee,
qu'elle ne fuit pas et qu'elle ne pr6sente
aucun autre defaut potentiellement
dangereux.
c. dans la mesure du possible, fermertoutes
les pores et fen_tres du b&timent, et
toutes les portes entre la piece o_ se
trouve I'appareil raccorde _,la tuyauterie
d'_vacuation et les autres pieces du
b_timent. Mettre en service les
s6ccheuses et tout autre appareil qui
n'est pas raccord6 _ la tuyauterie
d'_vacuation. Faire fonctionner _ regime
maximal tout ventilateur d'6vacuation,
tel que les hottes de cuisini6re et les
ventilateurs de salles de bains. Ne pas
mettre en service les ventilateurs d'_t_.
Fermer les registres des foyers.
d. respecter les instructions d'allumage.
Mettre en service I'appareil & ressai.
R6gler le thermostat de mani_re &ce que
I'appareil fonctionne sans interruption
e. S'assurer qu'un appareil muni d'un
coupe-tirage ne pr6sente aucune fuite ._
rouverture du coupe-tirage apr_s que ie
bn31eur principal ait fonctionn_ pendant
cinq minutes. Employer la flamme d'une
allumette ou d'une chandelle.
f. Apres avoir d6termin_ que tousles
appareils raccord_s _ la tuyauterie
d'_vacuation evacuent correctment tel
que prescrit ci-dessus, rouvdr les portes
et les fen_tres et remettre lesventilateurs
d'_vacuetion, les registres de foyers et
tout autre appareil fonctionnant au gaz
_,leur etat de fonctionnement initial.
g. Si un appareil n'evacue pas correctement
_,la suite de Pun des essais ci-dessus,
corriger la tuyauterie d'6vacuation.
Vent Pipe Material
Vent and combustion air pipe and fittings must
be one of the following materials and must
conform tothe 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
Foam/Cellular Core PVC F891
Cement and primer must conform to ATSM
Standard D2564 for PVC and Standard D2235
for ABS. When joining PVC piping to ABS, use
an appropriate solvent cement and procedure
per the piping manufacturer's recommendation
and 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 6,whichindicatesthe maximumallowable
piping length for a furnace of specified input
rate, when installed 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 lengthand the number
ofelbowson each pipe mustbe known. Choose
the diameter for which the tabulated length is
equal to or greater than required.
Use of the table is illustrated in the following
examples:
Example:
An 80,000 Btuh furnace isto be installed
in a "two-pipe" system with 40 feet of vent
piping. There are four elbows, excluding
those exterior to the building.
Solution:
Consulting Table 6, in the dual pipe length
column for an 80,000 Btuh furnace, the
maximum allowable length for a 3" inlet/
3" outlet is 90 feet with one elbow. Select
3" pipe. For two additional elbows, deduct
3.5 ft. for each elbow, or 7.0 ft. for a
maximum installed vent length of 83 ft.
Condensing furnace combustion products
have very little buoyancy, so Table 6 is to be
used without consideration of any vertical rise
in the piping. 13

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. 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).
CAUTION:
Combustion air must not be drawn from
a corrosive atmosphere.
_]-he qua!ity of outdoor air must also be
considered. Be sure that the combustion air
intake is not located near asource of solvent
fumes or other chemicals which can cause
corrosion of the furnace combustion system.
Piping must be mechanically supported so that
itsweight 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 & 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.
These condensing furnaces have been certified
for installation with zero clearance between
vent piping and combustible surfaces. However,
itisgood practice to allow space forconvenience
in installation and service.
Pipe Couplings at the Furnace
The provided rubber couplings should be in-
stalled in the combustion air (use 3" diameter
coupling) and vent (2" diameter) pipes to allow
for servicing. These couplings are designed to
fit snugly over the pipe and be secured to the
pipes using the provided hose clamps. Use 3"
x 2" flexible coupling at furnace on 2" vent pipe
and on upflow units use 3" diameter coupling
above coil box, as shown in Figures 14 and 15.
Refer to figures 14 and 15 for the proper
installation of these couplings.
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 13 illustrates necessary distances from
the vent termination to windows andbuilding
air intakes. In Canada, the Canadian Fuel
Gas Code takes precedence over these
draft vent
termin_d /Air Intet
Dite_ Vetlt
terminal -
more than
50,000 Btuh
Figure 13. Vent Termination Clearances
14

Upflow Furnace
Inlot -- Exhaust _\ I See Vent Table !
.(
I
=Seal/Cualk
*'_ __ _ :/_aroundpips
5/8"
I
I
Combustion
Air Inlet 7\ I
OtfsetwithExhau ! _
Pips for Adequate '
PVC or ABS ' -J
Neopren3e "_apl_nt_ r _ ' [
Straps or other suitable /at buildin
supports at minimum 5foot intervals _ ! /g
; o=,=E,ha°atVent 1="
| Wall _Y_._ MIn,
!
Exhaust Vent A/C Coil Normal Snow Level _
_,---- - "------ Box
'Flexible 3" x2= reducer to adapt the 2" diameter
vent pips of furnace to the 3" diameter pipe of the vent
--Fuma_
Downflow Furnace
SealiCautk I<
Around Pipe
atSu.dth0 \\ I
\
Min, i
Normal Snow Level
See Vent Table 4
Straps or Other Suitable
Supports at Minimum of
5 fL intervals
UpwardPitch - 1/4" Per Foot •
Wall Outlet Exhaust Vent
First Support Should he as Close to
Fumace ConnecUon as Possible --
Exhauat Vent
/Exhaust _lnlat
[/// 5/8"
Ii *
: TopView !
rrCombustion Air In_'t
Offset with Exhaust
Pipe for Adequate
Dimensioi_al Clearance
PVC or
ASS pipe
3" diamat_
Neoprene Coupling"
and 2 Clamps
Rax{b •3" x2 reducer to adapt the 2" diameter
vent pipe of furnace to the 3" dLameter pipe of the vent
Figure 14. Horizontal Venting
* These neoprene couplings are field-supplied and can be used if the installation requires
breakable connections inthe piping.Note thata maximum oftwocouplingsper pipeare allowed.
instructions. Specifically, all minimum
distance requirements with respect to
termination of the vent piping listed below.
The following list isa summary of vent terminal
location requirements:
1. The termination must be 12 inches above
snow level or grade level whichever is
higher. See Figure 17 for alternate method
to achieve 12" above snow level.
2. The minimum distance for adirect vent (2-
pipe) installation) from any door,
(openable) window, or air gravity inlet is 1
ft. below, 1 It. horizontally, or 1 ft. above.
3. The vent termination shall be a minimum of
3 ft. above any forced air inlet within 10 ft.
4. 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 Ca-
nadian Fuel Gas Code takes precedence.
5. Avoid areas where condensate drainage
may cause problems by dropping on
planters or patios, etc. Also ensure that
exhaust gases will not impinge on win-
dows or building surfaces, which may be
compromised or damaged by condensa-
tion. Do not install the vent terminal such
that exhaust isdirected into window wells,
stairwells, under decks or into alcoves or
similar recessed areas, and do not termi-
nate above any public walkways.
6. Select the point of wall penetration where
the minimum 1/4 inch per foot of slope up
can be maintained.
15

Upfiow Furnace
Rubber
Couplinl
Combustion
Air Pipe
3" Coupling
Furnace Front
Box
Fumace \
Support System
on VertJc_atRise
blow Joints
Support System wKh flmt support
as clolm to the furnace as posslbJe
114" per foot
3" diameter
Neoprene Coupling*
w/2 Clamps
Downflow Furnace
C
Exhaust
Support System
on Vertical Rise
Below Joints
Support System with flint support
as close to the furnace as possible
Upwa_ Pitch
l_'_rFoot
Flexible 3" x2" neducRr
to adapt tha 2" diameter
vent pipe of furnace to
the 3" diameter pipe of
the vent
Figure 15. Vertical Venting
Upflow Furnace Downflow Furnace
Combustion Air Inlet Pipe Collar
Diameter 3" for coupling or reducer
Fureace Top _
2" PVC Exhaust Vent All Models
Combustion Air Inlet
3" PVC on 0801t00 models
Furnace Top
_2" PVC
Exhaust Vent
All Models
Useappropriateadaptorforconnectiontofurnace. Useappropriateadaptorforconnectionto furnace.
Figure 16. Furnace Pipe Adaptions
16

CAUTION:
For optimal 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 18.
, WARNING:
Ensure thatthe combustion airvent and
the exhaust vent are configured as
shown in Fig. 18. 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 these oscillations occurring,
check the vent config uration. Make sure
that the exhaust vent does not have a 90
degree termination.
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 re-
tained on both sides ofthewall bythe couplings,
end 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 exte-
rior wall. Insure that the hole diameter is
less than the diameter of the couplings to
be used.
2. Extend the vent pipe through the wall
approximately 1" and seal the area be-
tween the wall and pipe.
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 has a 90
degree termination elbow, and is pointing
downward as shown in Figures 18 & 19.
Note that a combustion air intake must be
provided with an elbow opening downward.
For horizontal venting, one of the following kits
is recommended:
J .. vc.or,zono,J J
Exterior Vent 9023750
Mounting Kit
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
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 17.
Insulation is required to prevent freezing of this
section of pipe.
Table 7 describes the maximum length of flue
pipe that can travel through an unconditioned
space or an exterior space. The total vent
length must not exceed the lengths noted on
Table 6.
Vertical Venting
Figure 19 shows the proper installation and
clearances for vertical vent termination. The
Maximum Flue Pipe Length in
Unconditioned and Exterior Spaces
20 45 7O
020 70
-20 10 60
_:= Insulation thickness greater than 3/8 inch, based on an R value
of 3.5 (ft*°F*hr)/(BTU*in)
Table 7. Vent Protection
17

VentConfigurationto
Provide12"Minimum
height above
Snow LeveE. _. 12" Min,
19" Max.
Out,ide Su po.
wa,, •
_1/2"
_Armaflex
i _ Insulationor
Equivalent
-- 12" Above
Normally
Expected
Snow
Level
ExhaustVent
Op_on B _
Figure 17. Alternate Horizontal
Vent Installation
roof penetration must be properly flashed and
waterproofed witha plumbing roofboot or equiva-
lent flashing. Termination spacing requirements
from the roof and from each other must be per
Figure 19.
Figure 18. Exhaust and Combustion
Air Pipe Clearances
below freezing, i.e., installation within a pre-
existing masonry chimney; the pipe must be
insulated with 1/2 inch thick sponge rubber
insulation, such as an Armaflex-type or equiva-
lent.
Vent and combustion air piping may be in-
stalled 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.
b. The top of the chimney is sealed and
weatherproofed.
c. The termination clearances shown in
Figure 19 are maintained.
d. No other gas fired appliances are vented
through the chimney.
Vent Freezing Protection
To prevent condensate icing over extended
runs of vent pipe exposed to temperatures
Exhaust
; Vent's.
Combustion
Air
Exhaust
Plumbing Vent
Roof Boot
('ryp, Both Pipes)
iA= 12"AboveRooforSnowAccumulationLevel
Figure t9. Vertical Vent Termination
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 4) before this re-
duction isapplied. (Example: 3"to2-1/2") 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
listed in Table 13. For proper installation of the
concentric vent termination, follow the installa-
tion instructions provided with that kit.
DRAINAGE OF CONDENSATE FROM
FURNACE
/ WARNING:
The condensate produced by the fumace
m ust be drained. Do not connect a water
supply to the drainage hose of the
furnace.
NOTE: The condensate drain should be pro-
tected from freezing when in unheated spaces.
18

"HARD" J
Drain Tube
Left
Side
Drain
Route to
floordrain. I Routeto
Im mOR
18.... OR
, Route Io
condensate _ condel_sate
Clamp pump. Ksep _ Clamp pump¸ Keop
(LoosenForStepI) downward "HARD' J (LoosenForSlepI) downward
(RetightanforStep 3) slope. Drain Tube (R(_tightenforStep 3) slope.
Figure 20. Furnace with Condensate Drain Trap Assembly
The condensate drainage system is internal to
the furnace. The drain may exit either the dght
or left side ofthe furnace cabinet. For a right side
drain, simply extend the tubing out of the 7/8"
hole in the cabinet (See Figure 20).
For a left side drain follow the steps below:
1. Loosen the clamp on the soft exit tube
(see Figure 20.)
2. Rotate the soft exit tube (counter clock-
wise, 180° upflow models; clockwise 90 °
downflow models.)
3. Re-tighten the clamp. MAKE SURE
CLAMP IS TIGHT TO AVOID LEAKAGE
OF CONDENSATE.
4. Routethetubingout ofthe 7/8"hole located
8 inchesup fl'om the bottomfurnace.
The condensate shouid drain from the plastic
collector box (location A in Figure 20) as droplets
or a small stream. If you notice the furnace has
operated formorethan 5minutes 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 20 and insure the exit
from the collector box is clear of any
debris or obstructions.
2. Replace this tube and insure the fit to the
header spout isairtight. Airwill 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 itsacidity. If
the drain is not actively used or ifcodes require,
obtain a neutralizer kit (usually contains lime-
stone). 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
General
This furnace is equipped for either left or right
side gas entry. Typical gas service hook-ups
are shown in Figure 21. When making the gas
connection provide clearance between the
gas supply lineand the entryhole inthefurnace
casing to avoid unwanted noise and/or dam-
age to the furnace.
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 installation must comply with the provi-
sions stated inthe Federal Manufactured Home
Standard (H.UD Title 24, part 280 and the
National Fuel Gas Code (ANSI Z223.1/NFPA-
54) or (CAN/CGA B149) installation codes.
A drip leg should be installed in the vertical
pipe run to the unit. Table 8 lists gas flow
capacities for standard pipe sizes as a func-
tion of length in typical applications based on
nominal pressure drop in the line. 19

Typical Left Side Entry -Upflow
Burner Viewport
Roll_ut Limit
°Ourn r °'llll
Some Utilities Assembly
Require Shut- I F _
Off Valve to
be 4 to 5 feet
Above Floor - Ground
/Denotes field-
Automatic Gas Valve /provided and
(wdh manuel shut-off) installed
component.
Typical Right Side Entry -Downflow
Denotes field-
provided and Automatic
installed Gas Valve
components. (with manual
shut-off)
'Ground J<
, UrlioR
Burner Roll-Out Lim_
Assembly _,
Ii .....
int Some Utilities
1Require Shut-
Off Valve to
be 4 to 5feet
Above Floor
_-Bumer Viewport
Figure 21. Typical Gas Service Connection
NOTE: Gas piping must not be run in or
through air ducts, chimneys, gas vents,
elevator shafts, etc.
water column), the furnace must be discon-
nected 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.
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.
High Altitude Derate
The nameplate input rating for the furnaces
apply for elevations up to 2,000 feet (610m)
above sea level. For elevations over 2,000
feet, reduce the input by4% for each 1,000 feet
above sea level. For example, a furnace ap-
plied at an elevation of 5,000 feet should be
derated by 20%. See Table 9 describing the
correct orifice for derate.
NOTE: For Canadian high altitude (2,000 to
4,500 ft.), simply reduce the gas manifold
pressure to 2.8" WC for natural gas and 8.5"
WC for LP gas without changing the orifices.
NOTE: The density of air decreases with
increasing elevation above sea level. This
reduces the quantity of combustion air drawn
into the furnace under normal operation and
requires the unit be derated by using smaller
gas orifices or lower manifold pressure.
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 prop-
erly labeled by the installer in case emer-
gency shutdown is required.
CAUTION:
Do not use matches, lighters, candles,
or other sources of open flame to check
for gas leaks.
NOTE: When pressure testing gas supply
lines at pressures greater than 1/2 psig (14 in.
CAPACITY OF BLACK IRON GAS PIPE (CU, FT, PER HOUR)
FOR NATURAL GAS (SPECIFIC GRAVITY - 0.60)
i_OMI MAL LENGTH OF PIPE RUN
BLACK IRON _feet)
PIPE DIAMETER
(in. I10 2D 30 40 50 60 70 80
1/2 130 90 75 65 55 50 45 40
3#4 280 190 150 130 115 105 95 90
1520 350 285 245 215 195 180 170
1114 1050 730 590 5(0 440 400 370 350
1 1/2 1600 1100 890 7_ 670 610 560 530
T_ecubicfeetperhourlietedinthetableabovemustbegreeterthan
thecubicfeetperhourofgasflowrequiredbythefurnace.
To determine the cubic feet per hour of gas flow required by the
furnace, divide theinput rate ofthe furnace bythe heating value ofthe
gas:
CubicFeet -- InputTo Furnace (Btu/hr)
PerHourRequired HeatingValue ofGas (Btu/Cu, Ft.)
Table 8. Capacity of Black Iron Gas Pipe
(cu. ft. per hour) for Natural Gas
(specific gravity = .60)
2O