Owner`s manual

DV450S DIRECT VENT ROOM HEATER
01-01 Page 15 29863C
Figure 13
Retro-Fit to Metal
Chimney
D. Existing Class A Metal Chimney Termination
In many cases where a DOVRE DV450S is replacing a wood-
stove, much of the existing Class A Metal Chimney can be
incorporated into the direct vent system.
The existing chimney must comply with NFPA-211 codes and any
local code requirements.
The chimney should be cleaned and examined to verify
it is unobstructed and in good structural condition. Any
structural weaknesses such as cracks, leaky joints, cor-
roded or warped surfaces can have an adverse effect on
the performance of this Heater and should be replaced or
repaired.
Whenever an existing Class A Metal Chimney is on an outside
wall, removal of the chimney and the use of the minimum hori-
zontal direct vent termination kit may be less expensive.
When using an existing Class A Metal Chimney the following
requirements are necessary:
Minimum size diameter is 6 inches.
Minimum height from the base of the stove to the top of termina-
tion cap is 9 feet.
The vent from the top of the Heater to the Chimney must be rigid
vent sections. A 4'' UL 1777 listed gas vent aluminum flexible
liner can be used inside the chimney. The flexible liner must
be secured to the last rigid section with three (3) sheet metal
screws. A minimum 3 inch overlap is required. Remove and
discard the existing chimney termination cap.
Determine the length of the 4'' UL 1777 listed gas vent flex liner
required to meet the vent sections at the top of the Heater.
Follow the liner manufacturer’s instructions for installing the liner
in the chimney. Attach a flexible liner puller to the liner and
secure a rope to the puller. One person should feed the liner
through the chimney, and another person should pull the liner
from the bottom, with the rope, guiding the liner down the chim-
ney. Extend and run the 4'' gas vent liner down the chimney
leaving 10'' extending from the top of the chimney stack.
Install and secure the VTA (Vertical Termination Adapter) onto the
chimney with the brackets provided.
Place and secure the Termination Cap on the VTA with the
screws provided. See Figure 13.
VERTICAL
TERMINATION
CAP
VERTICAL
TERMINATION
ADAPTER
UL1777 LISTED
4'' GAS VENT
FLEX LINER
EXISTING
CLASS A
METAL
CHIMNEY
(6'' MIN. DIAMETER)
DURAVENT GS
VENT SECTIONS