Installation Guide

USSC 1110 USSC
Installation
PRIMARY FURNACE
SECONDARY (ADD-ON) FURNACE
When installed as a secondary furnace, it may only be connected to the ductwork of the existing primary furnace (Gas,
Electric, etc.). It should not be wired in conjunction with the existing furnace’s circuitry. A Duct Damper must be installed
between the air discharge of the 8500 furnace and the primary furnace. This duct damper prevents the air of the pri-
mary furnace from back owing to the secondary furnace. The damper must be a mechanical (spring return) style with
a simple closure switch to determine if the damper is opened or closed. The damper will connect to the 8500’s printed
circuit board (PCB) as a signal connection only. See wiring diagram in this manual. The PCB will not supply power to
an electronic damper requiring a power supply. This power supply must come from a different source.
CAUTION: Do not connect your furnace’s ductwork to the cold air return duct of your existing furnace because a pos-
sibility exists of components of the central furnace overheating and causing it to operate other than intended. Only con-
nect to ductwork that is in good condition. Never direct the air ow from the exisiting furnace thru the Add-On furnace.
Installation
THROUGH THE WALL INSTALLATION (RECOMMENDED INSTALLATION)
To vent the unit through the wall, connect the pipe adapter to the exhaust motor adapter. If the exhaust adapter is at least
24-inches above ground level, a straight section of pellet vent pipe can be used through the wall.
Your furnace dealer should be able to provide you with an installation kit, which will include a wall thimble that will allow
the proper clearance through a combustible wall. Once outside the structure, a 3-inch clearance should be maintained
from the outside wall and a clean out tee should be placed on the pipe with a 90-degree turn away from the house. At
this point, a 3-foot (minimum) vertical section of pipe should be added with a horizontal cap, which would complete the
installation.
A support bracket should be placed just below the termination cap or one every 4-feet to make the system more stable.
If you live in an area that has heavy snowfall, it is recommended that the installation be taller than 3-feet to get above the
snowdrift line. This same installation can be used if your furnace is below ground level by simply adding the clean-out
section and vertical pipe inside until ground level is reached. With this installation you have to be aware of the snowdrift
line, dead grass, and leaves. We recommend a 3-foot minimum vertical rise on the inside or outside of the house.
The “through the wall” installation is the least expensive and simplest installation. Never terminate the end vent under a
deck, in an alcove, under a window, or between two windows. We recommend Simpson Dura-Vent
®
or Metal-Fab
®
kits.
THROUGH THE ROOF/CEILING INSTALLATION
When venting the furnace through the ceiling, the pipe is connected in the same manner as a wall installation, except
the clean-out tee is always on the inside of the house, and a 3-inch adapter is placed in front of the clean-out tee.
You must use proper ceiling support anges and roof ashing (supplied by the pipe manufacturer; follow the pipe
manufacturer’s directions). It is important to note that if your vertical run of pipe is more than 15-feet, the pellet vent
pipe size should be increased to 4-inches in diameter.
Do not exceed more than 4-feet of pipe on a horizontal run and use as few elbows as possible. If an offset is required,
it is better to install 45-degree elbows rather than 90-degree elbows.
1 Vertical Cap
2 Storm Collar
3 Adjustable Roof Flashing
4 Cathedral Ceiling Support Box
5 Pipe
6 45° Elbow
7 90° Elbow
8 Horizontal Cap
9 Wall Thimble
10 Black Ceiling Support Firestop Spacer
11 Single Tee with Clean-Out Adapter
12 Tee Support Bracket
13 Double Tee with Clean-Out Adapter
This appliance requires the installation of a cold air return duct system. The return air will provide a better distribution
of warm air throughout your home, making the unit much more efcient than if installed without a return system.
CAUTION: MAINTAIN COMBUSTION
AIR SUPPLY TO BOTH FURNACES,
AIR STARVATION IS DANGEROUS.
OPERATE THE EXISTING FURNACE
PERIODICALLY TO ENSURE THAT IT
WILL OPERATE SATISFACTORILY,
WHEN NEEDED.
DO NOT RELOCATE OR BYPASS ANY
OF THE SAFETY CONTROLS IN THE
EXISTING FURNACE INSTALLATION.
REFER TO THE MANUFACTURER’S
INSTRUCTIONS OF YOUR EXISTING
FURNACE.
DO NOT USE DUCT ELBOWS HAV-
ING AN INSIDE RADIUS OF LESS
THAN 150mm (6 in.).
DO NOT CONNECT TO A DOWN
FLOW FURNACE.
DO NOT CONNECT DUCTWORK SO
THAT A REVERSE FLOW IS POSSIBLE.
This appliance must be installed by
experienced personnel and in accor-
dance with the instructions of the man-
ufacturer and in a manner acceptable
to the authority having jurisdiction.
When required by the authority having
jurisdiction, such personnel must be
licensed to perform this service.
All installation congurations require
the use of a return air system unless
specied otherwise herein.