Manual
4
INSTALLATION INSTRUCTIONS 
FOR CONVERTING A CLASSA 
METAL CHIMNEY OR MASONRY 
CHIMNEY TO A DIRECT VENT 
SYSTEM
These instructions apply to the DuraVent 
Direct Vent Conversion Kits for factory-
built Class A metal chimneys and masonry 
chimneys. These venting systems, in 
combination with the gas appliance, have 
been tested and listed by a major testing 
agency such as UL, AGA, Omni or Warnock 
Hersey. Check the manufacturer’s rating 
plate and instruction manual to conrm that 
a DuraVent Direct Vent Chimney Conversion 
system is approved for use on the brand 
name appliance you have selected.
IMPORTANT
Read all instructions carefully before starting 
the installation. Failure to follow these 
instructions may create a re or other safety 
hazard, and will void the warranty. Be sure 
to check the appliance manufacturer’s 
installation instructions for specic venting 
and clearance to combustible requirements, 
which may vary from one appliance to 
another.
INSTALLATION PRECAUTIONS
The DuraVent Direct Vent System is an 
engineered product that has been designed 
and tested for use with an approved list of 
direct vent gas appliances. The DuraVent 
warranty will be voided, and serious re, 
health, or other safety hazards may result 
from any of the following actions:
• Installation of any damaged Direct Vent 
component.
• Unauthorized modication of the Direct 
Vent System
• Installation of any component part not 
manufactured or approved by DuraVent.
• Installation other than as instructed by 
DuraVent and the appliance manufacturer.
Consult your local building codes before 
beginning the installation. 
Have the existing installation inspected by 
a qualied chimney sweep or professional 
installer, prior to converting to direct vent. 
The existing chimney system must be in 
serviceable condition, and functionally 
sound. The direct vent conversion described 
herein applies only to factory-built metal 
ceiling-supported type systems and masonry 
through-the-wall type systems. Note: You 
cannot install a Conversion Kit in a through-
the-wall type factory-built metal chimney.
GENERAL
Two dierent types of direct vent conversion 
systems are described here. One is through 
an existing factory built metal chimney going 
through the ceiling. The other is through the 
wall of an existing masonry chimney. Follow 
the appropriate directions for your situation. 
A typical direct vent conversion of a factory 
built metal chimney is shown in Figure 1. 
The concept of direct vent conversion is 
to connect an adapter to an Underwriters 
Laboratories listed 4-inch diameter aluminum 
ex pipe (DuraVent’s DuraFlex is an example 
of an UL listed ex pipe). This is then passed 
this down through the center of the existing 
metal chimney system. Three sizes of Top 
Adapters are available which should t 
most sizes and makes of metal chimney 
systems. The Retro Connector (909B) is then 
attached to the bottom of the ex pipe. Both 
the Top Adapter, and the Retro Connector 
are attached to the existing chimney with 
sheet metal screws. The appliance is then 
connected to the chimney with appropriate 
black direct vent pipe, and an adjustable 
length section.
A typical conversion of an existing masonry 
chimney is shown in Figure 6. For installation 
through the wall of an existing masonry 










