Installation manual
UltraGlow G36D Zero Clearance Direct Vent Gas Fireplace
22
4)  Separate the 2 halves of the wall thimble and 
securely fasten the one with the tabs to the 
outside wall making sure that the tabs are 
on top and bottom. Fasten the other thimble 
half to the inside wall. The thimble halves 
slip inside each other and can be adjusted 
for 2 x 4 or 2 x 6 walls. The liners must slip 
over the collars a minimum of 1-3/8".
5)  Slip the assembled liner and termination 
assembly through the thimble making sure 
the termination cap faces up (there are 
markings on the cap that show which way 
is up). This will position the termination cap 
with proper down slope for draining water. 
Fasten the cap to the outer wall with the 4 
supplied screws. 
6)  Pull the centre 4"(100mm) liner and outer 
  6-7/8"(175mm) liner out enough to slip over 
the fl ue collars of the fi replace. (You may 
wish to cut the liner shorter to make it more 
workable.) Do not bend liner more than 
90
o
.
7)  Apply Mill Pac over the fi replace inner collar 
and slip the 4"(100mm) liner down over it 
and attach with 3 supplied screws.
8)  Do the same with the 6-7/8"(175mm) liner.
9)  Apply a bead of silicone between the thimble 
and termination and around the outer edge 
of the terminal at the wall in order to keep 
the water out.
IMPORTANT: Do not locate termination 
hood where excessive snow or ice buildup 
may occur. Be sure to check vent termi-
nation area after snow falls, and clear to 
prevent accidental blockage of venting 
system. When using snow blowers, make 
sure snow is not directed towards vent 
termination area.
Note: To make the 
installation more 
aesthetically pleas-
ing, we recommend 
framing out a square 
to mount the termi-
nal to.
Offset Chart
INSTALLATION 
PROCEDURES
for UltraGlow Direct Vent 
System (Flex)
1)  Locate the unit in the framing, rough in the 
gas (preferably on the right side of the unit) 
and the electrical (Junction block is on the 
left side) on the left. Locate the centerline of 
the termination and mark wall accordingly. 
Cut a 10"(254mm) hole in the wall (inside 
dimension).
Note: A 1-1/2"(38mm) clearance around 
the liner must be maintained except 
that only a 1" (25mm) clearance is 
needed at the termination end. We 
recommend framing a 10"(254mm) 
x 10"(254mm) (inside dimensions) 
hole to give structural rigidity for 
mounting the termination.
Note: If installing termination on a siding 
covered wall, furring strips must be 
used to ensure that the termination 
is not recessed into the siding.
2)  Level the fi replace and fasten it to the fram-
ing using nails or screws through the nailing 
strips.
3)  Assemble the vent assembly by applying 
Mill Pac to the 4"(100mm) inner collar of the 
termination and slipping the 4"(100mm) liner 
over it at least 1-3/8" (35mm). Fasten with 
the 3 screws (drilling pilot holes will make this 
easier). Apply Mill Pac or high temperature 
silicone to the 6-7/8"(175mm) fl ex pipe and 
slip it over the 6-7/8" outer collar of the vent 
terminal at least 1-3/8"(35mm) and fasten 
with the 3 screws.
NOTE:   Horizontal sections must be sup-
ported at intervals not exceeding 3 
feet (0.9 meter). (Flame picture and 
performance will be affected by sags 
in the liner).
in Diagram 5 or local codes. Note that for 
steep roof pitches, the vertical height must be 
increased. A poor draft, or down drafting can 
result from high wind conditions near big trees 
or adjoining roof lines, in these cases, increas-
ing the vent height may solve the problem.
7)  Ensure vent is vertical and secure the base 
of the fl ashing to the roof with roofi ng rails, 
slide storm collar over the pipe section and 
seal with a mastic.
8)  Install the vertical termination cap by twist-
locking it.
Note:  Any closets or storage spaces, which 
the vent passes through must be 
enclosed. 
INSTALLATION










