79/80 Series Model Identification - Atwood 79 Series Service Manual

Applications - This unit is typically installed in tent campers, truck campers and small travel trailers due to its
small size and lower BTU capacities. It is sometimes used in larger trailers or motor homes for smaller zone
heating.
Heat Outlets - This furnace is usually set up as a front discharge unit. However, it does have a 4" duct outlet on
either side of its casing for soft ducting to remote outlets. To determine the most efficient ducting configuration,
refer to Minimum Ducting Configuration.
Directional Air Box Insert - If you need to direct heat to the front or rear of a camper and you cannot use soft
ducting and registers, an optional diverter plate with 55 degree louvers can be added to the front exhaust box.
Serviceability - Practically all of the components of this furnace are accessible by removing the front grille.
Therefore, the furnace does not need to be removed for most repairs. The only components that are not accessible
without removing the furnace are the blower motor, sail switch and blower and combustion wheels.
Power Consumption - The 79 series furnace draws only 3.4 amps. However, there is an 8012 series furnace that
has a heating capacity of 12,000 BTU's and only draws 1.8 amps. This furnace is ideal for dry camping.
MINIMUM DUCTING CONFIGURATION
7912-II 7916-II
Provides the most air flow and heat to remote heat
outlets. The duct runs need to be as short and straight as
possible for optimal heating.
7912-II 7916-II
with front discharge-
The majority of the heat discharges out the front. A
minimal amount of heat will pass through the side ducts.
These duct runs need to be as short as possible. An
optional air diverter with 55° angle vanes can be added to
front discharge opening to direct heat fore or aft in the
trailer.
8012-II 7912-II 7916-II 7920-II - FRONT DISCHARGE UNITS -
no ducts allowed on 8012-II
The heat discharges only through the front. The optional
air diverter noted above can be added to front discharge
opening to direct heat for or aft in the trailer.
RETURN AIR REQUIREMENTS
Return air is provided through the front door grill - approximately 33 square inches (213cm
installed at zero clearance, an additional 16 square inches (103cm
wheel side of the furnace.
79 / 80 Series Model Identification
MODEL DESCRIPTION
Model & Rate Input
79 -12-II = 12,000
16-II = 16,000
20-II = 18,000
80 -12-II = 12,000
Valve Setting & Power Usage
DC = Direct current 12 volts
Fitting Size Gas
6 = 3/8˝ flare
Venting or Ducting Options
A = vent length 4˝ approximate
B = vent length 8˝ approximate
C = vent length 12˝ approximate
7920-II - SIDE DISCHARGE UNITS -
7920-II - SIDE DISCHARGE UNITS -
79 I6-II DC 6
Duct #1
Duct #1
2 ) of return air must be provided to the blower
4
A
Front
Discharge
CLOSED
Duct #2
Front
Discharge
OPEN
Duct #2
Front
Discharge
OPEN
2 ). If the furnace is