Williams 1403622 Owner's Manual page 8

Installation
FIGURE 4
The gas line can be run at this time or after the furnace is
mounted. See "'Gas Supply and Piping" section.
No electrical power is required unless furnace is equipped with
an optional blower kit.
Do not connect a 115V service line to the gas valve or wall
thermostat.
Install Spacer Plate (Figure 5)
Install the mounting spacer plate with spacers entering and
centered within the 9-1/4 inch vent opening in the wall. Level
the top of the spacer plate (embossed top) and fasten it to the
interior wall using the six (6) #8 roundheaded (long) screws
provided.
Important: The vent tubes are factory equipped for walls 5 to 9
inches thick only. For wall thicknesses up to 24 inches, follow
the instructions packed with the appropriate factory Vent
Extension Kits.
Furnace Mounting (Figure 5)
Set the furnace body against the wall, legs on the floor, with
the vent tubes extending through the spacer plate.
Fasten the furnace to the wall through holes at the top and
bottom of the support legs using the four (4) #3 round headed
(long) screws provided.
Push the air inlet shield on from the exterior side of the wall.
Rotate the air inlet shield until the notches on the end of the
tube are straddling the standoff tabs on the mounting spacer
plate. Trim the air inlet shield flush with the exterior of the wall.
Never crimp the vent tubes or force them to fit.
Note: Do not trim flue extension or air inlet collar.
Install Vent Cap
Outside, place a single strip of mastic (provided) around the
back flange of the vent cap. (Figure 5). Install the vent cap by
inserting it into the air inlet tube and over the vent tube.
Important: The top of the vent cap is embossed "TOP". Install
it in the correct position to prevent water from entering the wall.
Level the vent cap and attach it to the outside wall with four (4)
#8 roundheaded (long) screws. (Figure 6).
8
If the wall surface is not flat (shiplapped siding, etc.) or less
than 5 inches thick, use a Thin Wall Collar Kit (9307) or, build
up a flat surface with wood strips. Do not tilt or bend the cap to
fit uneven surfaces. The vent cap flange must be tight against
the wall to prevent rain or wind penetration. Use standard
caulking compound if required (not provided).
For brick, masonry or plaster walls, it may be necessary to use
lag screws or expanding anchor bolts, which are not furnished
with the furnace.
When the vent cap is to be installed on vinyl siding, or a
projection within 6 inches of any side that could block the air
inlet, the entire vent should be supported away from the wall at
least the distance of the projection. A 2" x 4" frame, with
outside dimensions that match the overall dimensions of the
mounting plate, is recommended. The 2" x 4" frame protects
vinyl siding from possible damage. Seat and paint all joints.
The wall depth plus the additional 2" x 4" frame depth should
not exceed a total depth of 13 inches.
FIGURE 5
FIGURE 6
EXTERIOR WALL WITH VENT CAP
"TOP"