Kenmore 153.335963 - Manual (Page 18)

2. Horizontal runs require a minimum '/" rise per foot.
Installation Instructions (cont’d)
VENTING SYSTEM EXAMPLE INSTALLATIONS
FOR ALL MODELS
The vent piping cannot under any circumstances be run down­
hill.
The vent piping can be instiled as follows;
1. No more than 3 elbows can be used.
3. The total vertical and horizontal run cannot exceed 35'
for 3" vent piping (20' maximum if 2" vent piping is
used on 40,000 BTU/Hr. models) with a maximum of
three 90° elbows.
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