Suburban NT-12S Installation Manual

The design of these furnaces has been certified for installation in recreational vehicles only. In order for these furnaces to operate in conformity
with generally accepted safety regulations, the installation instructions outlined in this book must be followed. Failure to comply with the
installation instructions will void any responsibility of Suburban Manufacturing Company. Your furnace was inspected before it left the factory. If
any parts are found to be damaged do not install the furnace. Any damages should be reported to the transportation company immediately and
the appropriate claims filed.
WARNING! Improper installation, adjustment, alteration, service or maintenance can
cause property damage, personal injury or loss of life. Refer to the installation
instructions and/or owners manual provided with this appliance. Installation and service
must be performed by a qualified installer, service agency or the gas supplier.
W AR N IN G ! Installation of this appliance m ust be m ade in accordance w ith
the w ritten instructions provided in this m an ual. N o agen t, represen tative
or em ployee of Suburban or o th er person has the authority to change,
m o d ify or w aive any pro vision of the instructions contained in this
m anual.
C AU TIO N : If possible, do not install the furnace to w here the vent can be
covered or obstructed w hen any door on the trailer is opened. If this is not
possible, then the travel of the door m ust be restricted in order to provide
a 6" m inim um clearance betw een the furnace vent and any door w henever
the door is open.
N O T E : The exhaust tem perature o f this furnace could discolor or warp som e
m aterials. You should verify that the m aterial used on the coach door, panel, or
cover will not discolor or warp from the exhaust tem perature whenever any door,
panel, or cover is in the open position.
C AU TIO N : D ue to the differences in vinyl siding, this appliance should not
be installed on vinyl siding w ithout first consulting w ith the m anufacturer of
the siding or cutting the siding a w ay from the area around the appliance
vent.
C AU TIO N : In any in stallatio n in w hich the vent of this appliance can be
covered due to the construction o f the R V o r som e special feature of the R V
such as slide out, pop-up, etc. alw ays in su re that the appliance cannot be
operated by setting the therm ostat to the positive "O FF" position and
shutting off all ele c trical and gas supply to the appliance. N ever operate
furnace w ith vent covered.
T hese furnaces m ust be installed and vented as described in this m anual so that
the negative pressure created by the air circulating (return air) fan cannot affect
the com bustion air intake or venting of any other applian ce. It is im perative that
the products of com bustion be properly vented to the atm osphere and that all
com bustion air supplied to burner be drawn from the outside a tm osphere. (S ee
"Installing V ent Assem bly".)
IM P O R T A N T : If this furnace is to be connected to a com m on duct system also
serving a cooling unit, a m anual or autom atic dam per is required to prevent any
cold conditioned air from circulating back into the furnace. C old air passing over
the furnace com bustion cham ber during the operation of the cooling unit can result
in the form ation of condensation inside the furnace com bustion c h a m b e r. T his
condensation m ay prom ote corrosion an d prem ature failure of the com bustion
cham ber.
N O T E : These furnaces shall b e installed so the electrical com ponents are
protected from water.
T hese furnaces will accom m odate an installation depth from 23 3/8" m inim um
(with standard vent tube s), to 30 1/8" m axim um (with optional intake extension
tubes). (S ee Figure 1.)
P lease adhere strictly to the installation instructions to insure proper installation
and safe operation, as well as adequate clearances for accessibility.
T h ese furnaces are certified for use with propane/LP ga s on ly. G as su p p ly
pressure for purposes of input adjustm ent:
G as M inim um
P ropane/LP 11" W .C .*
*W ater colum n
R eturn air
R eturn air m ust be from the living area of the coach.
N O T E : R V 's that have a wall of separation to a cargo area (Toy B ox) to transport
internal com bustio n engine vehicles m ust not have return air opening from this
area.
A n opening m ust be provided in the interior cabinetry of the coach directly in front
of the furnace. The opening m ust allow for free, unobstructed rem oval of the
furnace. T his opening m ay be used as a m eans of providing circulating return air
INSTALLATION MANUAL
FOR MODELS
NT-12S • NT-16S • NT20S

INSTALLATION INSTRUCTIONS

M axim um
13" W .C .
SUBURBAN MANUFACTURING COMPANY
to the furnace. O ther openings m ay be used as well. The m inim um return air to
the furnace m ust total 55 square inches free area. It is im po rtan t that sufficient
return air be provided to insure norm al heating and operation of the furnace. Also,
adequate clearances m ust be m aintained around the furnace cabinet so that the
unit will be accessible for servicing. Failure to provide m inim um return air as well
as an adequate opening for furnace rem oval voids the warranty.
In the U S A , the installation m ust conform with local building codes. In the absence
of local building codes, refer to the latest edition of:
1-S tandard for R ecreational V ehicles A N S I A -119.2/N FP A 501C .
2-N ational Fuel C ode AN S I Z223.1.
T he furnace m ust be electrically grounded in accordance with the latest edition of
the N ational E lectrical C ode A N S I/N FP A N o. 70 . T he installation of the furnace
shall be in accordance w ith any applicable local codes and regulations.
In Canada, the furnace m ust be installed in accordance with:
1-S tandard CA N /C S A -Z240.6.2-M 86 E lectrical R equirem ents for R ecreational
V ehicles.
3-S tandard CA N /C S A -Z240.4.2-M 86 Installation R equirem ents for Propane
A ppliances and E quipm ent in R ecreational V ehicles.
4-C A N /C G A -B 149 Installation C odes
5-A ny applicable local codes and regulations.
TO IN S TALL TH E FU R N AC E
1. Locate the furnace near lengthwise center of the coach. D o not install the
furnace with the vent facing toward the forward end of the coach.
2. S elect a location for installation out of the way of wires, pipes, etc. that m ight
interfere with installation. Adhere to the following m inim um c learances from the
furnace cabinet to com bustible construction.
NT -12 • N T -16
Front 3/8" Floor 0"
S ides 1" Top 1"
B ack 0"
N O T E : Side and top clearances m ay be 0" for through the wall installations up to
a m axim um of 2 1/2" w all thick ness (S ee Figure 3.)
3. W hen an appliance is installed directly on carpeting, tile or other com bustible
m aterial other than wood flooring, the appliance shall be ins talled on a m etal or
wood panel extending the full w idth and depth of the appliance. If preferred, the
carpeting, tile or com bustible m aterials, other than w ood m ay be cut away the full
length and depth of the appliance plus the appliance m inim u m clearances to
com bustibles.
4. D eterm ine "X" dim ension as shown in Figure 1 or 2 depending on m odel.
5. D eterm ine "Y" dim ension as shown in Figure 1 or 2.
6. If X-Y is less than 22 3/4" for M odels N T -12 or N T -16, or 23 3/8" for M odel N T -
2 0, then an opening 9 5/8" x 9 3/8" m ust be cut through the inner wall only. D O
N O T C U T TH R O U G H C O AC H S K IN . (S ee Figure 3.) N ext, locate the center line
of the exhaust and intake tube. C ut two (2) 2 1 /4" diam eter holes through outer
skin as shown in Figure 5.
N O T E : W henever the furnace cabinet is installed through the outside wall, th e
return air louvers on the furnace cabinet m ust not be blocked. The m axim um
projection of the furnace cabinet into the wall is 2 1/2". (S ee Figure 3.)
N O T E : Furnace cabinet approved for 0" clearance to com bustible m aterials rear
2 1/2" of furnace cabinet.
7. If X-Y is 23 3/4" or greater for Model N T -12 or N T -16, or 23 3/8" or greater for
M odel N T -20, two m ethods m ay be used to install the furnace. They are:
a. C ut a 4" x 7 1/2" opening through com bustible w all as shown in F igure 4. D O
N O T C U T TH R O U G H TR AILE R S K IN . N ext, locate the center line of the exhaust
and intake tube. C ut two (2) 2 1/4" diam eter holes through trailer skin.
(S ee Figure 5.)
b. If you do not wish to cut the 4" x 7 1/2" opening, locate the center line of the
676 Broadway Street
Dayton, Tennessee 37321
N T -20S
Front 1" Floor 0"
S ides 1" T op 1"
B ack 0"