MORTEX
PRODUCTS
INC
501
TERMINAL
RD
FORT
WORTH,
TX
76106
Page
1
INSTALLATION MANUAL
DOWNFLOW ONLY GAS FURNACE
SIZES 60, 70, 77, 90
MODELS: G18D SERIES
CATEGORY I MOBILE HOME GAS FURNACE
LIST OF SECTIONS
1
–
Safety 1
6
–
Combustion
Air
and
Vent
System
19
2 – General Information
5
7 – Furnace Startup, Diagnostics and Sequence of Operation
27
3 – Furnace Duct connections and Duct System
8
8-
Blower
Performance
32
4 – Gas Supply and Valve Connections
10
9
–
Wiring
Diagrams
33
5 – Line and Low Voltage Wiring
14
LIST OF FIGURES
1 - Furnace Dimensions
7
18 – Typical Single Stage Heat / Cool Digital T’stat 2 Stage Furnace 18
2 – Duct Connector Dimensions
8
19 – Typical 2 Stage Heating/Cooling Digital T’stat Connections
18
3 – Duct Connector and Floor Base Installation
8
20 – Roof Jack Mounting Collars – Top of Furnace
20
4 – Air Distribution System – Single Trunk Duct
9
21 – Roof Jack Indoor Extension Pipes
20
5 – Air Distribution System – Double Trunk Duct
9
22 – Roof Jack Outdoor Extension Pipes
20
6 – Air Distribution Systems – Graduated trunk duct
9
23 – Roof Jack Assembly (Slope Saddle)
21
7 – Furnace Base Openings, Fuel, Electric & A/C Line Penetrations 9
24 – Roof Jack Crown Assembly
21
8 – Duct Connector Depths
9
25 – Combustion Air Path thru the Roof Jack & Thru the Pipes
22
9 - Outdoor Fresh Air Intake Knockout
10
26 –
Outside Ambient Combustion Air Openings and Ducts
23
10 – White Rodgers 36J29 Gas valve
11
27 – Home Layout and Vent Clearances
24
11 – Supply Gas Piping
11
28 – Outside Combustion Air and Vent Safety Check Procedure
25
12- Furnace Component Locations
16
29 – Typical Roof Jack Installation
26
13 – Separate T’stat, Furnace & Cooling Unit WD
17
30 – Reading the Inlet (Supply) Gas Pressure (INP)
29
14 – Separate T’stat, furnace, Cooling Unit & Trans W.D.
17
31 – Reading the Outlet (Manifold) Gas Pressure
29
15 – Same T’stat, Separate Furnace, Cooling Unit & Trans W.D.
17
32 – Integrated Control Board
30
16 – Same T’stat Separate Furnace, Heat Pump and Transformers
18
33 – Wiring Diagram A/C Ready Furnace
33
17 – Same T’stats Separate Furnace, Cooling Unit and Transformers 18
34 - Wiring Diagram Heating Only
34
LIST OF TABLES
1 – Furnace Clearances to Combustibles
6
10 – Recommended Thermostat Wire Colors & Connections
19
2
–
Model
Nomenclature
7
11
–
Estimated
Free
Area
22
3 – High Altitude Gas Orifice Chart
13
12 – Vent Clearances
24
4 – Gas Pipe Capabilities
14
13 –
Roof
Jack
Specifications
26
5 – Ratings and Physical Electrical Data
14
14 – Input Calculations for a cu-ft Gas Meter
28
6 – Heating Only Models 1/3 HP Blower and Motor Rating
15
15 – Input calculations for a Mj/m³ Gas Meter
28
7 – A/C Ready Models 1/3 HP Blower & Motor Rating
15
16 – Inlet (Supply) Gas Pressure Range
29
8 – A/C Ready Models 3/4 HP Blower & Motor Rating
15
17
–
Blower
Performance
32
9 – Low Voltage, Wire Gage and Max Lengths
16
SECTION I: SAFETY
This is a safety alert symbol. When you see this symbol on
labels or in manuals be alert to the potential for personal injury.
Understand and pay particular attention to the signal words
DANGER, WARNING,
or
CAUTION.
DANGER:
indicates an
imminently
hazardous situation, which if
not avoided,
will result in death or serious injury.
WARNING:
indicates a
potentially
hazardous situation, which if
not avoided,
could result in death or serious injury.
CAUTION:
indicates a
potentially
hazardous situation, which if
not avoided,
may result in minor or moderate injury.
It is also
used to alert against unsafe practices and hazards involving
property damage.
SAVE
THIS
MANUAL
FOR
FUTURE
REFERENCE
