
3
NOTE: These furnaces shall be installed so the electrical components are protected
from water.
These furnaces are design certied for propane gas only. Do not attempt to convert
to natural gas.
Gas supply pressure for purposes of input adjustment:
Minimum - 11” W.C.* Maximum - 13” W.C. *
(W.C.* - Water Column)
In the U.S.A., the installation of the furnace must be in accordance with local codes
and regulations. In the absence of local codes and regulations, refer to the latest
edition of:
1. Standard for Recreational Vehicles NFPA 1192.
2. National Fuel Gas Code ANSI Z223.1 / NFPA 54.
3. Furnace must be electrically grounded in accordance with the latest edition of
the National Electrical Code NFPA 70.
In Canada, the furnace must be installed in accordance with:
1. Standard CSA Z240.0.2-08 Recreational Vehicles.
2. CSA Standard Z240.6.2-08/C22.2 NO.148-08 Electrical Requirements for
Recreational Vehicles.
3. Standard Z240.4.2-08 Installation Requirements for Propane Appliances and
Equipment in Recreational Vehicles.
4. CAN/CGA-B149 Installation Codes.
5. Any applicable local codes and regulations.
This unit is equipped with an electric igniter device that has an energy consumption
of .1 amp @ 12 volts D.C.
WARNING
Extension tubes cannot be used. If you try to
extend the vent, it will result in improper installation
which could cause unsafe furnace operation.
There are three (3) common methods described below for installing the furnace.
Regardless of the method (see sections A., B., or C. below) you choose, we
require an opening be provided in the exterior of the trailer or motor home for free,
unobstructed removal of the furnace. This exterior, removable panel or wall section
of the trailer or motor home must be a minimum of 17-3/4 x 8.
It is important that adequate return air be provided to assure normal heating and
operation of the furnace. Failure to provide the minimum return air will cause erratic
furnace cycling. Refer to the chart shown below for minimum return air requirements.
RETURN AIR REQUIREMENTS
Model Minimum Free (unobstructed) Area
SF-20/25/30Q
SF-20FQ/25FQ/30FQ 55 Sq. In.
SF-35Q/35FQ 55 Sq. In.
SF-42Q/42FQ 142 Sq. In.*
*May be reduced to 88 sq. in. min. if 5 ducts are used.
TABLE 1
NOTE: Return air must be from within the living area of the coach.
NOTE: RV’s that have a wall of separation to a cargo area (Toy Box) to transport
internal combustion engine vehicles must not have return air openings from this area.
A. INSTALLATION DIRECTLY AGAINST OUTER PANEL OF COACH
(See Figure 2) (Panel supplied by installer)
Maximum wall thickness for this type installation is 2”.
1. Locate the furnace near lengthwise center of the coach.
2. Choose a location for installation out of the way of wires, pipes, etc., which
might interfere with the installation. Adhere to the minimum clearances from
the cabinet to combustible construction as listed in Table 2. Refer to Figure 1
for illustration of furnace clearances.
3. When an appliance is installed directly on carpeting, tile or other combustible
material, other than wood ooring, the appliance shall be installed on a metal or
wood panel extending the full width and depth of the appliance. If preferred, the
carpeting, tile or combustible materials, other than wood may be cut away the
full length and depth of the appliance plus the appliance minimum clearances
to combustibles. (See Table 2.)
4. Cut an opening through the inner wall. This will allow the rear of the furnace to
be installed against the outer panel of the coach.
5. Locate center lines for exhaust and intake, as shown in Figure 2, 4.
6. Cut two 2-1/4” diameter holes through the outer panel of the coach. (See
Figure 2, 4.)
7. Put furnace in place, making sure that rear of the furnace cabinet is as close to
outer panel of the coach as possible and still assure proper vent tube overlap.
(See Installing Vent Assembly.)
8. Secure furnace to the oor using the two (2) holes provided in the furnace
cabinet. (See Figure 6).
9. Be sure furnace is secured within furnace cabinet. (See Figure 6).
10. Install vent assembly. (See instructions for installing vent.)
B. INSTALLATION NOT AGAINST OUTER PANEL OR SKIN AND “X”
DIMENSION GREATER THAN 1 ½”
(See Figures 3, 5) (Exterior panel supplied by installer)
Maximum wall thickness for this type installation is 2”.
1. Locate the furnace near lengthwise center of the coach.
2. Choose a location for installation out of the way of wires, pipes, etc, which
might interfere with the installation. Adhere to the minimum clearances from
cabinet to combustible construction as listed in Table 2. Refer to Figure 1 for
illustration of furnace clearances.
3. When an appliance is installed directly on carpeting, tile or other combustible
material, other than wood ooring, the appliance shall be installed on a metal or
wood panel extending the full width and depth of the appliance. If preferred, the
carpeting, tile or combustible materials, other than wood may be cut away the
full length and depth of the appliance plus the appliance minimum clearances
to combustible. (See Table 2.)
4Determine “X” dimension as shown in Figures 3, 5. The tubes supplied with
the furnace will accommodate an installation range for “X” from o-1 ½”. If “X”
dimension is greater than 1 ½”, then special vent tubes as charted in Figures
3, 5 must be ordered.
WARNING
Do not alter, cut, or otherwise modify the vent
tubes as supplied by Suburban. Doing so could
result in inadequate intake of combustion air or
improper venting of furnace exhaust.
5. After determining “X” dimension, complete the furnace installation as follows:
6. Locate center lines for exhaust and intake tubes as shown in Figures 2, 4.
7. Cut two 2-3/4” diameter holes through the outer panel or outer skin. (See
Figures 3, 5.)
8. Put furnace in place, making sure that rear of furnace cabinet is as close to
inner wall section of the coach as possible and still assure proper vent tube
overlap. (See Installing Vent Assembly.)
9. Secure furnace to the oor using the two (2) holes provided in the furnace
cabinet. (See Figure 6.)
10. Slide furnace into cabinet. Be sure furnace is secured within furnace cabinet
(See Figure 6.)
11. Install vent assembly. (See instructions for installing vent.)
C. INSTALLATION USING THE FURNACE ACCESS DOOR SUPPLIED
BY SUBURBAN (See Figure 4)
Maximum wall thickness for this type installation is 2”.
1. Locate the furnace near lengthwise center of coach.
2. Choose a location for installation out of the way of wires, pipes, etc., which
might interfere with the installation. Adhere to the minimum clearances from
the cabinet to combustible construction as listed in Table 2. Refer to Figure 1
for illustration of furnace clearances.
3. When an appliance is installed directly on carpeting, tile or other combustible
material, other than wood ooring, the appliance shall be installed on a metal or
wood panel extending the full width and depth of the appliance. If preferred, the
carpeting, tile or combustible matters, other than wood may be cut away the full
length and depth of the appliance plus the appliance minimum clearances to
combustibles. (See Table 2.)
4. After furnace location has been determined, cut an opening 18-7/32 x 8-9/32”
through the inner coach wall and the outer wall (skin) of the coach.
5. Caulk around opening as illustrated. Apply generously. The purpose of the
caulking is to seal the back side of the door frame and the coach skin water tight.
6. Secure frame to outer wall (skin) through the holes in the frame. Screws should
be used. (See Figure 6.) NOTE: Do not place screws into the holes required
for mounting the door.
7. Slide furnace in place. The back of the furnace should be installed against or
as close as possible to the ange on the door frame. (See illustration.) The
furnace must maintain 1/2” overlap on the intake and 1-1/4” overlap on the
exhaust.
8. Secure furnace to the oor using the two (2) holes provided in the furnace
cabinet. (See Figure 6.)
9. Slide furnace into cabinet. Be sure furnace is secured within furnace cabinet.
(See Figure 6.)
10. Position furnace access door over the frame. Secure the door to the coach
skin. Be sure the coach skin is of sucient strength to keep furnace access
door in place and insure a tight seal. It may be necessary to build a wood
or metal frame around the opening in order to provide adequate strength for
securing door.
CAUTION
The screws provided with the door may not be of
sucient length and size for all applications and it may be
necessary for the installer to substitute screws in order to
adequately secure the furnace access door.
11. Install vent assembly. (See instructions for installing vent.)