John Wood Oil-Fired Direct Vent - Manual (Page 6)

Maintain clearances to Combustible material (2” x 4” or
2” x 6” framing) as per Table 1. Note: if the flex duct is
to be located between joists, the spacers provided must
be used to maintain clearances to combustible material.
Inside the home, attach the smaller end of the flex duct
to the vent terminal. Use the 3” band clamp with the
gasket attached (inside the clamp). The edges of the
band clamp must engage both beads (the one on the
vent terminal and on the flex duct) so that the gasket
straddles the joint.
Run the flex duct to the water heater. All bends should
be as generous as possible. Avoid sharp bends. Do not
kink the duct.
Support longer horizontal runs. Maximum spacing must
not exceed 3 feet. See Figure 2.
If the flex duct is run between ceiling joists, the spacers
as provided must be used. See the details in illustration
Figure 5.
Installation Clearances and
Clearances to Combustible Materials:
Heater Sides and Rear
Front of Heater
Above Heater
To vent Duct - Horizontal
Floor
2”
24”(Access for servicing)
24”
Above and one side - 1”
other side 6”
Below Duct- open to room
non combustible
Figure 5
FLOOR: NON-COMBUSTIBLE
CLEARANCES TO COMBUSTIBLE MATERIALS
TOP VIEW
2”
2” 2”
DO NOT ENCLOSE THIS AREA.
NO ENCLOSURE IS PERMITTED.
DETAIL OF SPACER IF INSTALLED
BETWEEN JOISTS MINIMUM CLEARANCE
TO COMBUSTIBLES 1”
1”
1”
36”
MAXIMUM SPACING FOR HANGING
24”
(FOR SERVICING)
2”
Page 5
1”