Heatilator • GDST4336I, GDFL4136I, GDCR4136I, GDCL4136I • 2129-900 Rev. F • 11/08 19
C
A
B
D
B. Constructing the Appliance Chase
A chase is a vertical box-like structure built to enclose the
gas appliance and/or its vent system. In cooler climates
the vent should enclosed inside the chase.
NOTICE: Treatment of ceiling fi restops and wall shield
fi restops and construction of the chase may vary with the
type of building. These instructions are not substitutes
for the requirements of local building codes. Therefore,
you MUST check local building codes to determine the
requirements to these steps.
Chases should be constructed in the manner of all out-
side walls of the home to prevent cold air drafting prob-
lems. The chase should not break the outside building
envelope in any manner.
Walls, ceiling, base plate and cantilever fl oor of the chase
should be insulated. Vapor and air infi ltration barriers
should be installed in the chase as per regional codes for
the rest of the home. Additionally, in regions where cold
air infi ltration may be an issue, the inside surfaces may be
sheetrocked and taped for maximum air tightness.
Figure 5.2 Clearances to Combustibles
To further prevent drafts, the wall shield and ceiling fi re-
stops should be caulked with high temperature caulk to
seal gaps. Gas line holes and other openings should be
caulked with high temp caulk or stuffed with unfaced in-
sulation. If the appliance is being installed on a cement
slab, a layer of plywood may be placed underneath to
prevent conducting cold up into the room.
G
F
I
E
H
* Adjust framing dimensions for interior sheathing (such as sheetrock)
GDST4336I
GDST4136
ABCDEFGHI
DVP Pipe SLP Pipe Rough
Opening
(Height)
DVP Pipe* Rough
Opening
(Width)
Clearance
to Ceiling Combustible
Floor Combustible
Flooring Ends of
Appliance Sides of
Appliance
Rough
Opening
(Width)
Rough
Opening
(Width)
Rough
Opening
(Depth)
Inches 10 8-5/8 38-1/8 23 43 31-5/8 0 0 1/2 36
Millimeters 254 219 968 584 1092 803 0 0 13 914
C. Clearances
NOTICE: Install appliance on hard metal or wood surfaces
extending full width and depth. DO NOT install directly
on carpeting, vinyl, tile or any combustible material other
than wood.
WARNING! Risk of Fire! Maintain specifi ed air space
clearances to appliance and vent pipe:
• Insulation and other materials must be secured to prevent
accidental contact.
• The chase must be properly blocked to prevent blown
insulation or other combustibles from entering and
making contact with fi replace or chimney.
• Failure to maintain airspace may cause overheating and
a fi re.