Intertherm M1B Series User manual

M1B, M1M & M5S Series
Downflow, Direct Vent (Sealed Combustion)
Forced Air Gas & Oil Furnaces
For installation in:
Buildings
damage.
instructions.
incendies.

2
..................... 3
..................................... 3
........................................ 5
Manufacturer Warranty ............................................ 5
Minimum Clearances ............................................... 5
Applications ............................................................. 5
Unit Location............................................................ 5
...................... 7
Return Air Connections............................................ 7
Supply Air Connections ........................................... 7
....................................... 8
General Information ................................................. 8
Locating & Cutting Duct Openings........................... 8
Standard Duct Connector Installation ...................... 8
Alternate Attachment Method................................ 9
Round Duct Connector Installation .......................... 10
Installing the Furnace .............................................. 10
................................... 11
Roof Jack Selection ................................................. 11
Locating & Cutting Roof/Ceiling Openings .............. 12
Installing The Roof Jack .......................................... 12
Installation of Transit-Mode Venting System ........... 13
.................................. 14
Line Voltage Wiring.................................................. 14
Connecting Power Supply Wires........................... 14
Low Voltage Wiring.................................................. 15
Connecting Thermostat Wires............................... 15
Verifying Anticipator Setting .................................. 15
Grounding ................................................................ 15
.......................................... 17
Leak Check.............................................................. 18
Oil Tank & Piping Installation................................... 18
One-Line System .................................................. 19
Two-Line System................................................... 19
Fuel line Hook-Up .................................................... 19
Fuel Line Bleeding ................................................... 19
Priming furnaces equipped with Honeywell........... 20
R7184 primary control:.......................................... 20
Priming furnaces equipped with Beckett 7505
primary control....................................................... 20
Fuel Oil Type ........................................................... 20
Conversion to Propane (LP) Gas............................. 20
Atmospheric & Direct Ignition Furnaces................ 20
High Altitude Conversion ......................................... 20
Flue Gas Sampling .................................................. 21
................................... 22
M1M Operating Instructions..................................... 23
How to Shut Off Gas - Direct Ignition .................... 23
M5S Operating Instructions ..................................... 23
M1B Operating Instructions ..................................... 23
How to Shut Off Gas - Oil & Gas Gun................... 24
Verifying & Adjusting Temperature Rise.................. 24
Burner Adjustments ................................................. 24
Gas Pressure ........................................................ 24
Combustion Air ........................................................ 24
Gas Gun (M1B Models)......................................... 25
Oil Gun Only (M5S Models) .................................. 25
Electrode Setting (Oil Gun Only) ............................. 25
Switching Ignition Control between Interrupted
and Intermittent Duty ............................................... 25
......................................... 25
Direct Ignition Furnaces (M1M Models)................... 25
Oil Gun Furnaces (M5S Models) ............................. 25
Gas Gun Furnaces (M1B Models) ........................... 26
................... 26
............................................... 27
Direct Ignition Furnaces (M1M Models) & Gas
Gun Furnaces (M1B Models)................................... 27
Oil Gun - Honeywell R7184 or Beckett 7505
Controls Only - M5S Series. .................................... 28
...................................... 29
......................................................... 30
Homeowner Information .......................................... 30
Installer Information ................................................. 30
Additional Oil Furnace Maintenance........................ 30
Optional Add-On Air Conditioning............................ 30
................................................. 31
Table 10. M1/M5 Furnace Specifications -
Factory Settings .................................................... 31
Table 11. Equivalent Orifice Sizes for High
Altitude Installations .............................................. 32
Table 12. A/C Blower Speed Selection Chart ....... 32
Gas Information ....................................................... 33
Table 13. Gas Flow Rates..................................... 33
Table 14. Gas Pipe Capacities.............................. 33
Electrical Information ............................................... 34
Figure 38. Gas Direct Ignition Furnace, Heating
& A/C Ready - All M1M Models............................. 34
Figure 39. Gas and Oil Furnaces, A/C Ready -
M1B & M5S (066, 086) Models ............................. 35
... 36

3
Safety markings are used frequently throughout this
manual to designate a degree or level of seriousness and
should not be ignored. indicates a potentially
hazardous situation that if not avoided, could result in
personal injury or death. indicates a potentially
hazardous situation that if not avoided, may result in minor
or moderate injury or property damage.
submerged underwater.
• 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
(NFPA54/ANSI Z223.1) or the Natural Gas and Propane
Installation Code, CAN/CGA B149.1.
• CEgénérateurd’airchauddoitêtreinstalléconformément
aux instructions du fabricant et aux codes locaux. En
l’absence de code local, respecter la norme ANSI
Z223.,1,instituléNationalFuelGasCodeoulescodes
d’installationCAN/GCA-B149.
• Use only with type of gas approved for this furnace.
Refer to the furnace rating plate.
• Install this furnace in accordance to the minimum
clearances to combustible materials listed in Table 1,
(page 6).
• Provideadequatecombustionandventilationairtothe
furnace space as specified on page 7and page 24.
Do not block or obstruct air openings on the furnace,
air openings to the area where the furnace is installed,
or the space around the furnace.
• Combustion products must be discharged outdoors.
Connect this furnace to an approved vent system, as
specified on pages 11 - 13.
• Never test for gas leaks with an open ame. Use a
commercially available soap solution to check all
connections. See page 18.
• Thisfurnaceisdesignedtooperatewithamaximum
external pressure rise of 0.5 inches of water column.
Consult Table 12, (page 32) and the rating plate for
thepropercirculatingairowandtemperaturerise.
It is important that the duct system be designed
tohandlethedesiredowrateandexternalpressure
rise. An improperly designed duct system can result in
nuisance shutdowns, and comfort or noise issues.
• Whensupplyductscarryaircirculatedbythefurnace
to areas outside the space containing the furnace, the
return air shall also be handled by duct(s) sealed to
the furnace casing and terminating outside the space
containing the furnace. See pages 8- 10.
• Thisfurnacemaynotbeusedfortemporaryheatingof
buildings or structures under construction.
• Theinformationlistedbelowisforreferencepurposes
only and does not necessarily have jurisdiction over
local or state codes.Always consult with local authorities
before installing any gas appliance.

4
Additional information listed below is for reference purposes only
and does not necessarily have jurisdiction over local or state
codes. Always consult with local authorities before installing
any gas appliance.
Combustion & Ventilation Air
• US:NationalFuelGasCode(NFGC),AirforCombustionand
Ventilation
• CANADA: Natural Gas and Propane Installation Codes
(NSCNGPIC), Venting Systems and Air Supply for Appliances
• USandCANADA:AirConditioningContractorsAssociation
(ACCA) Manual D, Sheet Metal and Air Conditioning
Contractors National Association (SMACNA), or American
Society of Heating, Refrigeration, and Air Conditioning
Engineers (ASHRAE) Fundamentals Handbook
• US:NationalElectricalCode(NEC)ANSI/NFPA70
• CANADA:CanadianElectricalCodeCSAC22.1
• US:NFGCandNationalPlumbingCodes
• CANADA:NSCNGPIC
General Installation
• US: Current edition of the NFGC and the NFPA 90B. For
copies, contact the National Fire Protection Association Inc.,
Batterymarch Park, Quincy, MA 02269; or American Gas
Association, 400 N. Capitol, N.W., Washington DC 20001 or
www.NFPA.org
• CANADA:NSCNGPIC.Foracopy,contactStandardSales,
CSA International, 178 Rexdale Boulevard, Etobicoke
(Toronto), Ontario, M9W 1R3 Canada
• US:(NFGC)NFPA54–1999/ANSIZ223.1andtheInstallation
Standards, Warm Air Heating and Air Conditioning Systems
ANSI/NFPA 90B.
• FederalManufacturedHomeConstructions&SafetyStandard
(H.U.D. Title 24, Part 3280.707[a][2])
• The Standard for Manufactured Home Installations
(Manufactured Home Sites, Communities, and Set-Ups) ANSI
A225.1 and/or CAN/CSA-2240 MH Series).
• American National Standard (ANSI-119.2/NFPA-501C) for
all recreational vehicle installations.
• CANADA:CAN/CGA-B149.1and.2–M00NationalStandard
of Canada. (NSCNGPIC)
• The Commonwealth of Massachusetts requires
compliance with regulation 248 CMR 4.00 and 5.00 for
installationofthrough–the–wallventedgasappliances
as follows:
1. For direct-vent appliances, mechanical-vent heating
appliances or domestic hot water equipment, where the
bottom of the vent terminal and the air intake is installed
below four feet above grade the following requirements
must be satisfied:
a.) A carbon monoxide (CO) detector and alarm shall be
placedoneachoorlevelwheretherearebedrooms.
The detector shall comply with NFPA 720 (2005
Edition) and be mounted in the living area outside
the bedroom(s).
b.) A (CO) detector shall be located in the room that
houses the appliance or equipment and shall:
•Bepoweredbythesameelectricalcircuitasthe
appliance or equipment. Only one service switch
shall power the appliance and the (CO) detector;
•Havebatteryback-uppower;
•MeetANSI/UL2034Standardsandcomplywith
NFPA 720 (2005 Edition);and Approved and listed
by a Nationally Recognized Testing Laboratory as
recognized under 527 CMR.
c.) A Product-approved vent terminal must be used, and
if applicable, a product-approved air intake must be
used.Installation shall be in strict compliance with the
manufacturer’sinstructions.Acopyoftheinstallation
instructions shall remain with the appliance or
equipment at the completion of the installation.
d.) A metal or plastic identification plate shall be mounted
at the exterior of the building, 4 feet directly above
the location of vent terminal. The plate shall be of
sufficient size, easily read from a distance of eight
feet away, and read “Gas Vent Directly Below”.
2. For direct-vent appliances, mechanical vent heating
appliances or domestic hot water equipment where the
bottom of the vent terminal and the air intake is installed
above four feet above grade the following requirements
must be satisfied:
a.) A (CO) detector and alarm shall be placed on each
oorlevelwheretherearebedrooms.Thedetector
shall comply with NFPA 720 (2005 Edition) and be
mounted in the living area outside the bedroom(s).
b.) The (CO) detector shall:
•Belocatedintheroomthathousestheapplianceor
equipment;
•Behard-wired,batterypoweredorboth.
•ShallcomplywithNFPA720(2005Edition).
c.) A product-approved vent terminal must be used, and
if applicable, a product-approved air intake must be
used.Installation shall be in strict compliance with the
manufacturer’sinstructions.Acopyoftheinstallation
instructions shall remain with the appliance or
equipment at the completion of the installation.

5
A warranty certificate with full details is included with these
instructions. Carefully review these responsibilities with
your manufactured housing dealer, service company or
gas supplier. It is the sole responsibility of the homeowner
to make certain the gas furnace has been correctly set up
and converted to the proper fuel (L.P. gas or Natural gas)
and adjusted to operate properly. All gas furnaces are
manufactured for Natural gas and must be field converted
when using L.P. gas.
The manufacturer will not be responsible for any costs
found necessary to correct problems due to improper
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:
• Convertingthefurnacetouseanothertypeofgas.
• Repairingductworkinthehomefoundtobefaulty.
• Correcting wiring problems in the electrical circuit
supplying the furnace.
• Resettingcircuitbreakers,blownfusesorotherswitches.
• Correcting problems due to improper gas supply
pressure to the furnace.
• Providing instructional training on how to light and
operate the furnace.
• Furnace problems caused by installation of an air
conditioner, heat pump or other air comfort devices.
• AddingaRoofJackextensionbecauseofunusualwind
and/or snow conditions.
• Revisinginstallationofthefurnaceueassembly(Roof
Jack).
• Adjustingorcalibratingofthermostat.
• Anyconstructiondebriswhichfallsintouesystem.
Minimum Clearances
This heating appliance must be installed with clearances
not less than the minimums listed in Table 1, (page 6).
This furnace must be installed with ample clearance for
easy access to the air filter, blower assembly, burner
assembly, controls, and vent connections. See Figure 1,
Figure 2, and Figure 3 (page 6).
• Thedimensionsoftheroomoralcovemustbeableto
accommodate the overall size of the furnace and the
installation clearances listed in Table 1 and in Figure 4
(page 6).
• Alcove installations: minimum 18” clearance at front
of furnace shall be provided for future servicing. A
removable access panel should be installed between
top of the furnace door frame and the ceiling.
• Closetinstallationsmustusealouvereddoorhaving
a minimum free area of 235 in2when located 6” from
furnace or 390 in2for 5 ton ready M1/M5 furnaces. For
special clearance between 1” - 6”, requirements are a
louvered door with a minimum of 250 in2free area, with
the openings in the closet door in line with the louvered
openings in the furnace door. A fully louvered closet
door may be used. See Circulating Air Requirements
on page 7.
• Thefurnacemustbekeptfreeandclearofinsulating
material. Examine the furnace area when the furnace is
installed or when insulation is added.Insulating material
may be combustible.
M1 Series gas and M5 Series oil furnaces are listed direct
vent(sealedcombustion),downowheatingappliancesfor
manufactured (mobile) homes, recreational vehicles, and
for use in residential/modular/commercial construction.
The furnace must be located so that venting can be
properly achieved.
Air conditioning may be added to structures with M1/M5
series furnaces using air conditioning or conventional
units. This Installation Instruction manual includes
special requirements for incorporation of air conditioning
equipment to the M1/M5 series of furnaces. See Table
12, (page 32).
Multi-speed blower assemblies shown in Table 2, (page
6), have been certified for field installation in M1/M5
Series furnaces.
• Thefurnaceshallbeappropriatelylocatedtothesupply
and return air distribution system (page 7). Sides and
back of the furnace may be enclosed by wall framing.
See Minimum Clearances and Figure 1, Figure 2, and
Figure 3 (page 6).
• Thefurnaceinstallationisonlyintendedforfreeairreturn
through the furnace door louvers. DO NOT connect a
ducted return air system directly to the furnace.Improper
installation may create a hazard and damage equipment,
as well as void all warranties.
• Furnacemaybeinstalledoncombustibleooringwhen
using manufacturer approved duct connectors. See
pages 8-10.
• Wheninstalledinaresidentialgarage,thefurnacemust
be positioned so the burners and the source of the
ignition are located no less than 18 inches above the
oorandprotectedfromphysicaldamagebyvehicles.

6
Figure 1 Figure 2 Figure 3
Figure 3.
Removable access
panel should be
installed above
furnace door frame
to access roof jack
Nearest
Wall or
Partition
18"
(457 mm)
6" (152 mm)
Top Clearance
0" Side
Clearance
to Furnace
Cabinet
6" (152 mm)
Top Clearance
0" Side
Clearance
to Furnace
Cabinet
Provide min. 235
sq. in. (1516 cm )
open free area in
front or side wall
2
or
In closet
door
located
at top,
center
or bottom
CLOSET DOOR
6" (152 mm)
Top Clearance
Provide min. 250
sq. in. (1613 cm )
open free area in
front or side wall
2
a fully
louvered
door may
be used
CLOSET DOOR
6"
(152 mm)
1"
(25 mm)
0" Side
Clearance
to Furnace
Cabinet
or
in closet
door
Figure 2. Closet Installation
Figure 1.
Figure 4
“A”- 56"
23 3/4"
“B”- 76"
“A” Model
w/o Coil
Cabinet
“B” Model
w/Coil
Cabinet
19 3/4”
Figure 4.
Table 1
Table 1. Minimum Clearances
Front 6” 18”
Back 0” 0”
Sides 0” 0”
Roof Jack 0” 0”
To p 6” 6”
Top and Sides of Duct 0” 0”
Bottom of Duct — —
B Cabinet 0” 0”
A Cabinet (w/ coil box) 0” 0”
A Cabinet (w/o coil box) 1/4” 1/4”
Table 2
Table 2. Blower Assemblies
NO.
(TONS)
903773 10 x 8 1/4 2, 2½ & 3
903413 11 x 8 1/2 2, 2½, 3 & 4
903890 11 x 8 3/4 2, 2½, 3, 4 & 5

7
U.S.A. home manufacturers shall comply with all of the
following conditions to have acceptable return air systems
for closet installed forced air heating appliances:
• Thereturnairopeningintotheclosetshallnotbeless
thanspeciedintheappliance’slisting.
• The cross-sectional area of the return duct system
leading into the closet, when located in the oor or
ceiling shall not be less than 235 in2(or 390 in2for 5
ton ready M1/M5 Furnaces).
• Meansshallbeprovidedthatpreventinadvertentclosure
ofatobjectsplacedoverthereturnairopeninglocated
intheoorofthecloset(versustheverticalfrontorside
wall).
• Thetotalfreeareaofopeningsintheoororceiling
registers serving the return air duct system must be at
least 235 in2. At least one register should be located
where it is not likely to be covered by carpeting, boxes
and other objects.
• Materialslocatedinthereturnductsystemmusthavea
amespreadclassicationof200orless.Thisincludes
a closet door if the furnace is in a closet.
• Noncombustiblepanshaving1”upturnedangesare
locatedbeneathopeningsinaoorductsystem.
• Wiringmaterialslocatedinthereturnductsystemshall
conform to Articles 300-22 of the National Electrical
Code (ANSI C1/NFPA-70).
• Gaspipingisnotruninorthroughthereturnductsystem.
water column.
• Testthenegativepressure in theclosetwiththeair-
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.
• Airconditioningsystemsmayrequiremoreductregister
andopenlouverareatoobtainnecessaryairow.Use
NORDYNE’s certiduct program to determine proper
duct sizes for air conditioning.
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.
Location, size, and number of registers should be selected
onthebasisofbestairdistributionandoorplanofthe
home.
Three typical
distribution systems are shown in Figure 5
Figure 5
Figure 5.
A Single trunk duct
BDual trunk duct
w/crossover connector
C
Transition duct
w/branches

8
These Installation procedures are suggested for
typical furnace installations. Since each installation is
different, the sequence of instructions may differ from
the actual installation. Only qualified HVAC technicians
should install this furnace.
The installer must be familiar with and comply with all
codes and regulations applicable to the installation of
these heating appliances and related equipment. In
the absence of local codes, the installation must be in
accordance with the current provisions of one or more of
the following standards.
• Federal Manufactured Home Constructions & Safety
Standard (H.U.D. Title 24, Part 3280.707[a][2])
• AmericanNationalStandard(ANSI-119.2/NFPA-501C)
for all recreational vehicle installations.
• AmericanNationalStandard(ANSI-Z223.1/NFPA-54)
and/or CAN/CSA B149 for all gas-fired furnace models.
• American National Standard (ANSI-Z95.1/NFPA-31)
and/or CSA B139 for all oil-fired furnace models.
• AmericanNationalStandard(ANSI-C1/NFPA-70)and/or
CSA 22.1 Canadian Electric Code Part 1 for all electrical
field wiring.
• UnitshavebeenresearchedunderstandardsUL307A
& B, UL727-1999, ANSI Z21.47b/CSA 2.3b-2008, and
CSA B140.10.
• Thefurnacemustbeleveledatinstallationandattached
to a properly installed duct system.
See page 7for
circulating requirements.
• The furnace must be installed so that all electrical
components are protected from water.
• Thedimensionsoftheroomoralcovemustbeableto
accommodate the overall size of the furnace and the
installation clearances listed in Table 1, (page 6)
and Figure 1 (page 6)
• The furnace must be installed upstream from a
refrigeration system.
• The M1 Series gas and M5 Series oil furnace is
certiedforuseonwoodooringorsupports,butmust
be installed on top of a duct connector. This factory
suppliedaccessorymustbeinstalledintheoorcavity
and attached to the supply air duct before the furnace
is installed.
Floor cut-outs and fuel line holes must be carefully located
to avoid misalignment of the furnace, and vent piping.
To locate standard ducts see Figure 6 (page 9). For
round ducts, see Figure 7.
1. Measure 10” from the rear wall or alcove and mark the
centerlineofthecut-outontheoor.
2. Using the centerline as a starting point, draw the rest
of the duct cut-out to the dimensions shown in Figure
6or Figure 7.
3.Cutouttheooropening1/16”largerthantheactual
cutout drawn. This will allow some clearance when
installing the duct connector.
4.Measurefromthetopoftheoordowntothetopofthe
supplyairducttoobtainthedepthoftheoorcavity.
Thedepthoftheoorcavityshownas“X”in
Figure 9 (page 9) will determine the correct duct
connector.
5. Determine which duct connector to use from Table 3
(page 9).
6. Measure and drill gas hole and cut out for cooling coil
(if applicable). See Figure 6 or Figure 7.
Standard Duct Connector Installation
The standard duct connector is designed for use on ducts
12” in width. However ducts narrower than 12” may not
allow sufficient clearances for this type of installation. For
an alternate installation method, see page 9.
1.Center the duct connector in the oor opening with
bottom tabs resting on top of the supply air duct.
2. Mark the cut-out area on the supply air duct by tracing
around the connector tabs of the duct connector. See
Figure 8 (page 9).
3. Remove the duct connector and cut out the marked
area of the supply air duct 1/4” larger the actual cutout
drawn.
4.Installtheductconnectorbackintheooropeningwith
the bottom tabs extending into the supply air duct.
5. Install the mounting plate under the back side of the
duct connector as shown in Figure 8. Align the screw
holes in both components.
6. Secure the duct connector and the mounting plate to
thewoodoorwithappropriatesizescrews.
7. Bend the connector tabs on the bottom of the duct
connector upwards and as tight as possible against
the supply air duct.
8. Bend both tabs up 90° on the mounting plate. See
Figure 10 (page 10).
9. Seal all connections with industrial grade sealing tape
or liquid sealant.
Requirements for sealing ductwork vary
from region to region. Consult with local codes for
requirements specific to your area.

9
Alternate Attachment Method
The standard duct connector is designed for use on ducts
12” in width. However if there is insufficient clearance to
bend the duct connector tabs, this alternate attachment
method may be used.
1. Score and cut the top of the supply air duct as indicated
in Option 1 or Option 2. See Figure 11 (page 10).
If Option 1 is selected, cut out the metal from
the shaded area.
2.Foldthetwoaps(Options1or2)uptoformtheopening
for the duct connector.
3. Install the duct connector with the bottom tabs extending
into the supply air duct.
4. Bend the tabs on the bottom of the duct connector
upwards and as tight as possible against the supply
air duct. See Figure 12 (page 10).
5.Form the aps (Options 1 or 2) up against the duct
connector as tight as possible.
6.Securetheductconnectorapstothesupplyairduct
with staples (3 minimum) or if a 2x block/joist is not
provided, use sheet metal screws (2 minimum).
The duct connector tabs may be attached to
the air duct with sheet metal screws or other suitable
fasteners as long as the duct connector and the air duct
are securely attached.
7. Seal all connections with industrial grade sealing tape
or liquid sealant.
Requirements for sealing ductwork vary
from region to region. Consult with local codes for
requirements specific to your area.
Figure 6
FLOOR CUT-OUT
FOR STANDARD
DUCT CONNECTORS
C
L
C
L
C
L
24"
23 1/4"
21 3/4"
14 1/2"
2 1/4"
2 3/4"
20"
CUT-OUT FOR
OPTIONAL
COOLING COIL
REAR WALL OF CLOSET OR ALCOVE
1 3/4"
2"
3/4"
C
L
C
L
C
L
10"
C
L
FURNACE OUTLINE
14 1/2"
ALT FUEL-LINE
ENTRY 1 1/4" Dia.
FURNACE
OUTER
DOOR
FUEL
LINE
1 3/4"
3/4"
1 7/8"
2 7/8"
Figure 6.
Standard Duct Connectors
Figure 7
FLOOR
CUT-OUT FOR
ROUND DUCT
(14 1/4” DIAMETER)
C
L
C
LC
L
C
L
24"
23 1/4"
21 3/4"
20"
CUT-OUT FOR
OPTIONAL
COOLING COIL
ALT FUEL-LINE
ENTRY 1 1/4" Dia.
FURNACE
OUTER
DOOR
REAR WALL OF CLOSET OR ALCOVE
FUEL
LINE
1 3/4"
2"
3/4"
C
L
C
L
10"
FURNACE OUTLINE
1 3/4"
10"
3/4"
1 7/8"
2 7/8"
C
L
Figure 7.
Figure 8
Bend tabs
up 90°
Mounting Plate
Duct
Connector
Connector
Tabs
Supply
Air Duct
Hole for
Gas Line
Wood Floor
Figure 8. Standard Duct Connector Installed
Figure 9
“X”
FLOOR OPENING
FLOOR
CAVITY
SUPPLY AIR DUCT
Figure 9.
Table 3
7/8” / (22) 901987A 904008
2” / (51) 901988A 904009
4-1/4” / (108) 901989A 904010
6-1/4” / (159) 901990A 904011
8-1/4” / (210) 901991A 904012
10-1/4” / (260) 901992A 904013
12-1/4” / (311) 901993A 904014
Dimensions shown as Inches / (Millimeter)
Table 3.

10
1. Apply a bead of caulking, mastic, or other approved
sealant around bottom side of connector.
2.Installandcentertheductconnectorintheooropening.
3. Install the mounting plate under the back side of the
duct connector. See Figure 13. Align the screw
holes in both components.
4. Secure the duct connector and the mounting plate to
thewoodoorwithappropriatesizescrews.
5. Connect the round supply duct to the underside of the
duct connector and secure them with field supplied
sheet metal screws.
6. Seal all connections with industrial grade sealing tape
or liquid sealant.
Requirements for sealing ductwork vary
from region to region. Consult with local codes for
requirements specific to your area.
Sides and back of the furnace may be enclosed by wall
framing such as in a closet or alcove. The dimensions
of the room or alcove must be able to accommodate the
overall size of the furnace shown in Figure 4 (page 6)
and the installation clearances outlined on page 5. The
furnace shall be appropriately connected to the supply
and return air distribution system as shown in Figure 14
(page 10) & Figure 15 (page 11).
1. Remove furnace outer door(s) and bottom fuel line
knockout.
2.Placefurnaceontoductconnectorandcenterwithoor
opening.
3. Slide onto mounting plate. (Bottom rear slots on furnace
should engage with mounting plate tabs.)
4. Secure front with one (1) fastener at each corner. See
Figure 14 & Figure 15.
Additional fasteners may be used at rear, sides
or through door frame, as desired, to secure furnace to
closet or alcove framing.
Figure 10
DUCT CONNECTOR
SUPPLY
AIR DUCT
BEND TABS TIGHTLY
AGAINST SUPPLY AIR DUCT
Figure 10. Duct Connector Tabs
Figure 11
Figure 11.
OPTION 1 OPTION 2
Supply
Air Duct
Fold Flap Here
Fold Flap Here
Remove
this
Flap
Remove
this
Flap
Cut Here
Cut Here
Cut Here
Cut Here
Cut Here
Cut Here
Cut Here
Cut Here
Cut Here
Fold Flap Here
Fold Flap Here
Figure 12
Narrow
Duct
Narrow
Duct
Duct connector tabs
Staples or sheet metal screws
Duct
Flap
Narrow
Duct
Duct
Connector
Sheet metal
screws
Figure 12. Narrow Ducts
Figure 13
DUCT
CONNECTOR
MOUNTING
PLATE
SCREWS
FUEL LINE
HOLES
14” SUPPLY CONNECTION
Figure 13.
Figure 14
MTG. PLATE TABS SLIDE FURNACE
ALL THE WAY BACK
ONTO MTG. PLATE
SUPPLY AIR DUCT
Knockout Over Holes
SECURE FURNACE
WITH 2 FASTENERS AT FRONT
CORNER HOLES
Figure 14.

11
Required ceiling and roof cut-out openings must be
carefully located to avoid misalignment of the furnace
and Roof Jack. Install only Roof Jack Assemblies
listed in Table 4 on this heating appliance.
1. Determine depth of ceiling cavity from center of roof
opening to center of ceiling opening (Dimension A in
Figure 16).
2. Determine ceiling height and subtract height of furnace
(Dimension B in Figure 16).
3.Add dimensions A + B (and X from Table 5, (page
12) & Figure 6 if slant deck ashing is used). The
totallengthof[A]+[B]+[X]mustbewithintheminimum
and maximum range of the Roof Jack listed in Table 4.
Application Notes
• FAW,FAWT,SAWandSAWTSeriesRoofJackswitha
5” diameter inner vent pipe may be used with all models
of M1 Series gas and M5 Series oil furnaces.
F=FlatFlashing:exesfrom0/12to1/12roofslope.
See Figure 17 (page 11).
S=SlantFlashing:2.5/12Slopeexesfrom1/12to
4/12roofslope,4/12exesfrom3/12to5/12.
See Figure 18 (page 12).
• Stainlesssteelroofjacksareavailable.
• M1/M5furnacesmaybeusedwithroofjacksastallas
170” (except M1M 056 & M1B 066 models, which are
limited to 120”). An internal roof jack extension (p/n
901935 - 10”, p/n 903107 - 18”) can be used to increase
roof jack height. All connections inside the home must
be made below the ceiling.
• Thisfurnacemustneverbeconnectedtoachimney
ueservicingareplaceorotherappliancedesigned
to burn solid fuel.
If the roof jack crown is covered or blocked
with snow, the furnace will not operate properly. If the
home is located in regions where snow accumulation
exceeds 7” (HUD snowload zones) use an external roof
jack extension (p/n 901937). Extensions are optional
accessories and may be purchased through your
NORDYNE distributor.
Figure 15
FUEL LINE HOLES
MTG. PLATE TABS
SLIDE FURNACE
BACK AGAINST
MTG. PLATE
SECURE FURNACE
WITH 2 FASTENERS
AT FRONT CORNER HOLES
SUPPLY
AIR DUCT
Figure 15.
Figure 16
ROOF JACK
SLANT DECK
FLASHING
PITCHED
ROOF
CEILING
CEILING
CAVITY
Roof
Opening
"X" (SEE TABLE 5)
Flue Pipe
Combustion Air Pipe
56" or 76"
Furnace
“A”
“B”
Figure 16.
Figure 17
Figure 17.
ROOF JACK
SLANT DECK
FLASHING
PITCHED
ROOF
CEILING
ROOF
OPENING
"X" (SEE TABLE 5)
CEILING
CAVITY
CEILING
OPENING
Table 4
Table 4.
SSAW T27 47 - 2
AW= ALL WEATHER FLASHING
PITCH/12" RISE
0=FLAT
2=2.5/12
4=4/12
MIN. ADJ.
LENGTH
F = FLAT FLASHING
S = SLANT FLASHING
TYPE:
BLANK = NON-TRANSIT
T= TRANSIT MODE MAX. ADJ.
LENGTH
FLUE STEEL TYPE
A= ALUMINIZED
S=STAINLESS
(F,S)AW(T)1523-(0,2,4)(A,S) 15” - 23”
(F,S)AW(T)2135-(0,2,4)(A,S) 21” - 35”
(F,S)AW(T)2747-(0,2,4)(A,S) 27” - 47”
(F,S)AW(T)3563-(0,2,4)(A,S) 35” - 63”
(F,S)AW(T)5195-(0,2,4)(A,S) 51” - 95”

12
connection is made.
Refer to the installation instructions provided
with optional air conditioning packages when installing
furnaces with optional cooling coil cabinet or with optional
C* series indoor coils.
1. Locate center of Roof Jack opening, measure 13 1/2”
from the rear wall of closet or alcove along the center
lineoffurnaceandooropening.SeeFigure 19.
2. Cut ceiling and roof holes:
•Ceiling=83/4”(222mm)diameter
•Roof=93/8”(238mm)diameter
1.Applycaulkingcompoundonundersideofroofashing
to form a continuous strip at least 3/8” wide around the
undersideoftheperimeteroftheashing.SeeFigure
20 or Figure 21 (page 13).
2. Connect Roof Jack Assembly to the furnace. Insert
telescoping Roof Jack Assembly through the opening
cut on the roof.
3.Connectuepipetouecollaroffurnace.SeeFigure
22 (page 13).
4. Connect combustion air pipe to furnace collar with sheet
metal screw. See Figure 22.
• Itisrecommendedthattheconnectionofthecombustion
airpipetothefurnacebemadebeforetheashingis
secured to the roof to maintain alignment of roof jack
and furnace connections.
• Forreplacementfurnaces,besuretheinneruepipe
connects over the furnace vent collar. DO NOT use a
5.AttachRoofFlashing.Ifnecessary,shiftroofashing
slightly in the roof opening so that assembly is in
alignment with furnace.
Ifashing is mounted on12degreeangle,it
may be necessary to adjust the angle to match the roof
pitch; (1/12 - 4/12 maximum).
6.Pressdownrmlyonroofashing(overcaulking)to
make the seal with roof water tight.
7.Secureashingwithappropriatefasteners. For
addedprotectionagainstleaks,coattheashingplate
and fasteners with approved roofing compound.
Figure 18
Figure 18.
5/12 ROOF SLOPE
2
SLANT DECK
/12
12
ROOF JACK WITH
2
FLASHING
/12 SLANT
12
Figure 19
CEILING
CUT-OUT FOR
FLUE AND
ROOF JACK
C
L
C
L
24"
20"
13 1/2"
REAR WALL OF CLOSET OR ALCOVE
10"
FURNACE
OUTER
DOOR
FURNACE OUTLINE
Figure 19.
Table 5
Table 5.
IS:
“F Series
2” in 12” 903893 (2.5/12) 2-1/8”
2-1/2” in 12” 903893 (2.5/12) 2-1/2”
3” in 12” 903894 (3/12) 2-7/8”
3-1/2” in 12” 903894 (3/12) 3-1/4”
4” in 12” 903895 (4/12) 3-5/8”
4-1/2” in 12” 903895 (2.5/12) 2-1/8”
5” in 12” 903895 (2.5/12) 2-1/2”
5-1/2” in 12” 903894 (3/12) 2-7/8”
6” in 12” 903894 (3/12) 3-1/4”
6-1/2” in 12” 903895 (4/12) 3-5/8”
Optionaldeckashingsforatand2.5/12pitchroofjacks.
4/12 pitch roof jacks not applicable.

13
Figure 21
Upper Roof Jack Section
Secure lower roof
jack section with
no. 10 S.M. screws
Caulk under roof
ashing to prevent
water leakage
Optional Slant
Deck Flashing
Secure ashing
with appropriate
fasteners
Ceiling
Figure 21.
1. Furnace must be installed in accordance to furnace
installation manual.
2. Select appropriate Roof Jack from Table 4, (page 11)
3. Roof Jack (less upper Roof Jack crown), with weather
cap to be installed as described under Install Roof Jack.
Upper Roof Jack crown to be stored in a
prominent location inside manufactured home until
on-site installation.
4. The four warning tags supplied must be installed as
follows:
•Toweathercap
•To fuel line connection point (Gas) or furnace
burner (Oil)
•Tofurnaceameobservationdoor(GasorOil)
•Tofurnacewallthermostat
5. Transit-mode weather cap to be removed and upper
Roof Jack crown installed. See Figure 23. Do Not
Discard screws.
6.PlaceupperRoofJack(crown)ontheuepipeassembly.
Makesureinsideuepipeattachesoverinner
uepipeandouterRoofJackpipetsoverouterpipe.
7. Secure in place using three, #10, 1/2” sheet metal
screws removed in step 5. Do not use the same holes
which secured the rain cap in place.
8. Remove and discard venting system warning tags.
Figure 23
SCREWS
COMPLETED
ASSEMBLY
TO FURNACE
UPPER ROOF
JACK (CROWN)
INNER FLUE
PIPE
FLUE ASSEMBLY
OUTER PIPE
FLASHING
WEATHER CAP
Figure 23.
Figure 20
Secure roof jack with
appropriate fasteners
after connecting to
furnace
Caulk under roof
flashing to prevent
water leakage
Roof
Ceiling
Optional 2-piece ceiling
ring #902521
Figure 20.
Figure 22
Figure 22.

14
Line Voltage Wiring
connections.
• Electricalconnectionsmustbeincompliancewithall
applicable local codes with the current revision of the
National Electric Code (ANSI/NFPA 70).
• For Canadian installations the electrical connections
and grounding shall comply with the current Canadian
Electrical Code (CSA C22.1 and/or local codes).
It is recommended that 115VAC line voltage be supplied
to the furnace from a dedicated branch circuit containing
the correct fuse or circuit breaker for the furnace as listed
in Table 6, (page 16).
Figure 38 (page 34)& Figure 39 (page 35)
jurisdiction.
15).
Route all electrical wiring to the left side of the furnace.
See Figure 24. For installation of A-size Cabinet furnaces,
allow sufficient slack in the wiring if an optional cooling
coil cabinet is added at a later time.
conductors is recommended.
Connecting Power Supply Wires
1. Remove the furnace control panel cover.
2. Route wires (115 VAC) through the strain relief on the
left side of the furnace control box (Figure 24).
3. Connect the wire to the pigtail lead, and
the neutral wire to the pigtail lead. Secure all
connections with suitable wire nuts.
4. Connect the ground wire to the grounding screw.
5. Reinstall the control panel cover and secure with the
original mounting screws.
Figure 24
Figure 24.
On-Off
Switch
Blower
Plug
Power
Entry
On-Auto Switch
(Heating Models Only)
Thermostat Wires
Furnace
Control Box
To combustion
Blower or Flame
Roll-out Switch
To Gas Valve
or Burner
damage.

15
Low Voltage Wiring
• Thefurnaceisdesignedtobecontrolledbya24VAC
thermostat.Thethermostat’swiringmustcomplywith
the current provisions of the NEC (ANSI/NFPA 70) and
with applicable local codes having jurisdiction.
• The thermostat must be installed according to the
instructions supplied by the thermostat manufacturer.
Low voltage connections (24 VAC) from the thermostat
are wired to the terminal strip on the integrated control
in the furnace.
• Thethermostatshouldbemountedabout5feetabove
theooronaninsidewall.DONOTinstallthethermostat
on an outside wall or any other location where its
operation may be adversely affected by radiant heat from
fireplaces, sunlight, or lighting fixtures, and convective
heat from warm air registers or electrical appliances.
Refertothethermostatmanufacturer’sinstructionsheet
for detailed mounting information.
• The nominal anticipator setting is 0.4. Refer to the
thermostat literature for additional information.
• Five-conductorthermostatwireisrecommendedfor24
volt low-voltage circuit (2-wire is required for furnace
only; 5-wire for heating and optional cooling systems).
Refer to Table 6 for thermostat wire information.
Connecting Thermostat Wires
1. Insert 24 volt wires through the plastic grommet just
above the control panel.
2. Connect the thermostat wires to the furnace low voltage
pigtails. See Figure 25.
3. Connect low-voltage circuit to the wall thermostat.
4. A hole may be made in the furnace cabinet to ease
thermostat wiring. Make sure that the wiring is protected
from the sharp edge of the added hole.
Verifying Anticipator Setting
After the furnace is installed, check the thermostat
anticipator against the nominal setting of 0.4.
1. Connect the milliamp meter in series with one of the
gasvalve’slowvoltageterminals.
2. Energize the gas valve.
3. Read the value of the milliamps.
4. Adjust the heat anticipator of the thermostat to the
value on the milliamp meter. If the heat anticipator is
set too high, the furnace may delay turning on. If set too
low, the furnace may cycle frequently and not provide
comfort to the homeowner.
Grounding
Figure 25
Figure 25.
Rc
R
H
W
G
Y
Red
White
Green
Yellow
Red
White
Green
Grey
Thermostat M1/M5 A/C
Ready Furnace

16
Table 6
Table 6.
(IN.)
NOMINAL
1
2
M1MB 056 56,000 19 3/4 115-1-60 103 127 7.0 14 15 8.5 14.5
M1MB 070 70,000 19 3/4 115-1-60 103 127 7.0 14 15 8.5 14.5
M1MB 077 77,000 19 3/4 115-1-60 103 127 7.0 14 15 8.5 14.5
M1MB 090 90,000 19 3/4 115-1-60 103 127 7.0 14 15 8.5 14.5
M1BB 066 66,000 19 3/4 115-1-60 103 127 6.8 14 15 8.3 14.3
M1BB 086 86,000 19 3/4 115-1-60 103 127 6.8 14 15 8.3 14.3
M1MC 056 56,000 19 3/4 115-1-60 103 127 8.9 14 20 10.9 18.8
M1MC 070 70,000 19 3/4 115-1-60 103 127 8.9 14 20 10.9 18.8
M1MC 077 77,000 19 3/4 115-1-60 103 127 8.9 14 20 10.9 18.8
M1MC 090 90,000 19 3/4 115-1-60 103 127 8.9 14 20 10.9 18.8
M1BC 066 66,000 19 3/4 115-1-60 103 127 8.7 14 20 10.7 18.6
M1BC 086 86,000 19 3/4 115-1-60 103 127 8.7 14 20 10.7 18.6
Minimum wire gauge and maximum fuse/circuit breaker amperage are based on MCA1and MOP2calculations. This furnace is approved
for installation with a 15 or 20 amp fuse/circuit breaker however wiring sizing must adhere to current version of the NEC and/or applicable local
codes depending upon the overcurrent protection.
24 55 ft. 25 ft.
22 90 ft. 45 ft.
20 140 ft. 70 ft.
18 225 ft. 110 ft.
* Time-delay fuses or circuit breakers are required.

17
This furnace may be installed with left, right, or bottom gas
entry. When connecting the gas supply, 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. Typical gas service hookup for this furnace
is shown in Figure 26 (page 18).
Table 14, (page 33)listsgasowcapacitiesforstandard
pipe sizes as a function of length in typical applications
based on nominal pressure drop in the line.
19).
unit.
18)&
19)
Figure
21)
instructions.
incendies.

18
Optional fuel inlet lines are available for all gas
furnace models to permit the addition of a 1/2” F.P.T.
shut-offvalveabovetheoor.
The gas supply to your home will either be Natural Gas
or L.P. (bottle gas). Your furnace is factory equipped to
operate on Natural Gas. If your gas supply is L.P. (bottle
gas), you must contact a qualified serviceman or gas
supplier to convert the furnace. Instructions for conversion
to propane are shown on page 20. Factory installed
orifice sizes are listed in Table 10, (page 31).
For natural gas operation, the furnace is designed for 7”
W.C. inlet pressure. Pressure is reduced to 3 1/2” W.C.
by the pressure regulator in the gas valve. The maximum
inlet pressure for the valve is 7” W.C and the minimum
inlet pressure is 4.5” W.C.
For L.P. gas, pressure to the gas valve must be more than
11” W.C. but not more than 13” W.C. Pressure is reduced
to 10” W.C. by the pressure regulator in the gas valve.
Figure 26
To Gas
Supply
Floor
Control
Panel
On-Off-Fan
Switch
Alt. Fuel
Line Entry
Floor Cavity
Figure 26.
After the gas piping to the furnace is complete, all
connections must be tested for gas leaks. This includes
pipe connections at the main gas valve, emergency
shutoffvalveandexiblegasconnectors(ifapplicable).
The soap and water solution can be applied on each
joint or union using a small paintbrush. If any bubbling is
observed, the connection is not sealed adequately and
must be retightened. Repeat the tightening and soap
check process until bubbling ceases.
The following procedures are recommended as good
practice. However, requirements of local codes and
ordinances, H.U.D. Manufactured Home and Safety
Standards or National Fire Protection Association must be
satisfied, where they apply, for an approved installation.
• Useatankcapacitysuitablefortheapplicationwitha
weatherproof, capped fill opening and a shielded vent
to let in air as fuel is used.

19
Figure 27
Figure 27.
If fuel pump fails to lift oil, check for air
port plug and repeat priming procedure.
leaks and tighten all fuel fittings. Re-
prime fuel pump by injecting fuel oil into
optional (top) return port. Replace return
Top of Tank
8 ft.
Shut-off
Valve
Optional
Fuel
Filter
Alternate
Fuel Line
Entry
Control
Panel
Oil
Furnace
On-Off-Fan
Switch
Floor Cavity
Oil-Gun
Burner
Floor
Flue Gas
Sampling
Hole
Drain
End of Oil Supply Line
3" to 5" Above Bottom Drain
Guide
Pipe
Gauge
Vent with cap 2" Duplex
Bushing
2" Fill
3/8" Oil Supply Line
NOTE: Additional venting may be
required if tank is filled rapidly.
4 GPH 100-150 PSI 3450 RPM
3 GPH 150-200 PSI 3450 RPM
VALVE ON DELAY
NO. 2 & LIGHTER FUEL
USE ONLYWI TH
INLET
BY-PASS
Exclusively forBe ckett
Madeby Suntec
INLET
NO.2 FU EL
A2EA-6520
Becket
t
Nozzle Port
3/16 Flare Fitting
Bypass Solenoid Valve
Cordset
Inlet Port
1/4 NPTF
Bleed & Gauge Port
Pressure Adjustment
Screw
Inlet Port
1/4 NPTF
Return Port - Install 1/6” Bypass Pipe
Plug for 2-pipe System Only.
(Use 5/32” Allen Wrench)
• Theinsideofthetankmustbecleanbeforelling.All
water,rust,sediment,anddebrismustbeushedout.
• Afuelortankgaugeisrecommendedforeasychecking
of the fuel level.Check the gauge reading with a dipstick.
See Figure 27.
• Locatethestoragetankconvenientlynearthehome.
If the fuel tank is installed above ground, the tank may
rest 3 to 4 inches off the ground. Fuel tanks may also
be buried if properly coated to resist corrosion. The
vertical dimension from the bottom of the fuel tank to
the fuel pump must not exceed 10 feet.
• Keepthetanklled,especiallyinthesummertoreduce
the accumulation of condensation.
One-Line System
The One-Line System is highly recommended where
vertical lift, from bottom of tank to pump, is less than 8
feet (Figure 27). A single line hookup has the advantage
of lower cost and quieter operation.
Two-Line System
If a Two-Line system is used or if oil is taken from the
bottom of the tank, a filter is recommended. A Two-Line
system should only be used if vertical lift exceeds 8 feet.
1. Install the oil feed line as outlined in steps 1 - 6 below.
2. Install the oil pump bypass plug in the bottom return
port.
3. Route the return line up through the furnace base to
the return port of the pump. Route the other end of the
line to the tank, using 3/8” O.D. copper tubing or 1/4”
pipe with the ends capped.
4. Insert the return line through the second opening in the
duplex bushing. If the bottom of the tank is lower than
the pump intake, the tube should be inserted three or
four inches from the tank bottom. If the bottom of the
tank is higher than the pump intake, the return line
should extend not more than 8” inside the tank.
1.Use a 3/8” O.D. copper tubing for the fuel line.
Cap the end with tape to keep out dirt while the
line is being routed.
2. Install duplex bushing for two 3/8” lines in the top fitting
of the tank. See Figure 27.
3. Insert one end of the tubing through the duplex bushing
until it is three to five inches from the bottom drain.
Tighten the bushing.
4. Route the line where it will not incur any damage. Make
bends gradual and avoid kinks which might restrict oil
ow.
5. Open the furnace door and connect the oil line to the
intake port on the pump. Tighten other port plugs on
the pump. Verify the oil line is airtight! Air leaks
can cause the pump to lose prime and will create other
problems such as nozzle failure, odors, rumbling noise,
and false safety shutdown.
6. Insert the short length of the copper tube level with the
bottom of the duplex bushing. Form the tube into an
inverted “U” to serve as a vent.
Fuel Line Bleeding
To eliminate problems caused by air in the oil line, all
connections in the oil supply line and all plugs, nuts,
and fittings on the pump must be airtight. This
includes the nut that covers the pressure adjustment. It
is important that the hook-up be done carefully and with
agoodaringtool.
Prepare the burner for priming by attaching a clear plastic
hose over the bleed port fitting and fully opening the pump
bleed port. Use a suitable container to collect purged oil.
To ensure continuous operation, use a wire to jump
terminals (or ) on the primary control while burner
is running.

20
Priming furnaces equipped with Honeywell
R7184 primary control:
1. While the ignition is on, press for 1/2 second (or less),
and release the reset button. The lockout time will be
extended to 4 minutes.
2. If prime is not established within the 4 minutes, the
control will lock out. Press the reset button to reset the
control.
3. Repeat steps 1 & 2 (if needed) until the oil pump is fully
primed.
Priming furnaces equipped with Beckett 7505
primary control
1. After the burner starts, press and hold the reset button
until the yellow LED turns on (15 seconds). This indicates
that the button has been held long enough.
2. Release the reset button. The yellow LED will turn off
and the burner will start up again.
3. At burner start up, click the reset button while the igniter
is still on. This transitions the control to a dedicated pump
prime mode, during which the motor, igniter and valve
are powered for 4 minutes. The yellow LED will be on.
If prime is not established during the four minute
pump prime mode, repeat step 3 until the oil pump is
fully primed.
4.Whenoilowisclear and free of air bubbles,close
air-bleed valve and tighten. Air bleed out time
will varies depending on length of oil line, number of
bends, etc.
Do not use fuel oil heavier than Grade No. 2. In areas
where the oil supply is subject to low temperatures, Grade
No. 1 may be used.
This gas fired heating appliance was shipped from the
factory for use with natural gas. However, the appliance
can be converted for use with LP gas. Use the following
procedure for gas conversion of the burner.
Atmospheric & Direct Ignition Furnaces
1. Follow the instructions “How to Shut Off Gas” (page
23).
2. Disconnect the gas pipe union and the electrical wires
connected to the gas valve.
3. Remove the gas valve assembly:
a. Remove screw(s) from gas valve bracket. Gas valve
and spud may be removed. Orifice is located at the
end of the spud (M1M Models)
b. Remove three (3) bolts from U-shaped manifold plate
and orifice assembly (M1B Models).
5. Replace the main orifice with the L.P. gas orifice supplied
in the envelope located by the gas valve. Verify the
orifice size matches the nameplate or Table 10, (page
31).
6. For Honeywell gas valves with the regulator converter:
a. Unscrew the pressure regulator cap and check for
the letters NAT or LP. See Figure 28 (page 21).
b. Invert the cap and tighten until snug.
7. For Robertshaw gas valves with the regulator converter:
a. Remove the black cover and unscrew the converter
located on top of the gas valve. See Figure 29 (page
21).
b. Invert the converter.For LP, the red ring will be located
at the bottom and the LP stamping on the converter
will appear right side up.
c. Screw converter back into the regulator, hand tight
plus 1/8 turn.Replace the black cover on the converter
top to protect the threads.
8. Reassemble the burner assembly into the furnace.
9. Reconnect the gas piping and electrical wires to the
gas valve.
10.Open the manual shut-off valve and follow the Lighting
and Operating instructions on page 23
High altitude conversion with this furnace depends on
the installation altitude and the heating value of the gas.
The installation of this furnace at altitudes above 2,000
feet must meet the requirements of the National Fuel Gas
Code or local jurisdiction. In Canada, the requirements for
high altitude are different and governed by CGA B149.1.
Please consult your local code authority.
This manual suits for next models
2
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