OWNER'S OPERATION AND INSTALLATION MANUAL UNVENTED (VENT-FREE) GAS LOG HEATER VRL24NR, VRL24PR, VRL30NR, VRL30PR, CSG3924NR, CSG3924PR CTB3924NR, CTB3924PR 24" and 30" Thermostat Models: VRL24NT, VRL24PT, VRL30NT, VRL30PT, CSG3924NT, CSG3924PT CTB3924NT, CTB3924PT

110021-01A
For more information, visit www.desatech.com
For more information, visit www.desatech.com
11
11
INSTALLING DAMPER CLAMP ACCESSORY
FOR VENTED OPERATION
(Remote-Ready Models Only)
Note: When used as a vented heater, appliance must be installed
only in a solid-fuel burning fireplace with a working flue and
constructed of noncombustible material.
If your heater is a manually-controlled, you may use this heater as
a vented product. There are three reasons for operating your heater
in the vented mode.
1. The fireplace does not meet the clearance to combustibles re-
quirements for vent-free operation.
2. State or local codes do not permit vent-free operation.
3. You prefer vented operation.
If reasons number 1 or 2 above apply to you, you must permanently
open chimney flue damper. You must install the damper clamp
accessory (to order, see Accessories, page 34). This will insure vented
operation (see Figure 10). The damper clamp will keep damper open.
Installation instructions are included with clamp accessory.
See chart below for minimum permanent flue opening you must
provide. Attach damper clamp so the minimum permanent flue
opening will be maintained at all times.
Area of Various Standard
Round Flues
Diameter (ins.) Area (sq. ins.)
5" 20 sq. inches
6" 29 sq. inches
7" 39 sq. inches
8" 51 sq. inches
Chimney Minimum Permanent
Height (ft.) Flue Opening (sq. ins.)
6' to 15' 39 sq. inches
15' to 30' 29 sq. inches
INSTALLATION
Continued
INSTALLING HEATER BASE ASSEMBLY
WARNING: You must secure this heater to fire-
place floor. If not, heater will move when you adjust
controls. Moving heater may cause a gas leak.
WARNING: If installing in a sunken fireplace, spe-
cial care is needed. You must raise the fireplace floor to
allow access to heater control panel. This will insure
adequate air flow and guard against sooting and con-
trols being damaged. Raise fireplace floor with noncom-
bustible material. Make sure material is secure.
CAUTION: Do not pick up heater base assembly
by burners. This could damage heater. Only handle
base assembly by sides of base.
IMPORTANT: Make sure the heater burners are level. If heater is
not level, heater will not work properly. For thermostat models,
avoid damage to thermostat bulb. Avoid nicks or sharp bends in
thermostat bulb wire. Keep thermostat bulb in mounting bracket
until ready to mount base to floor. See Optional Positioning of
Thermostat Sensing Bulb, page 27.
Installation Items Needed
• hardware package (provided with heater)
• approved flexible gas hose and fitting (not provided) (if allowed
by local codes)
• sealant (resistant to propane/LP gas, not provided)
• electric drill with 3/16" drill bit (metal or masonry as applicable)
• flathead screwdriver
1. Connect fitting to base as shown in Figure 11. Connect approved
flexible gas hose to fitting in base (see Figure 11).
IMPORTANT: Hold gas fitting with wrench when connecting
flexible gas hose.
Figure 10 - Attaching Damper Clamp
Damper
D
Damper
Manufactured Fireplace
Masonry Fireplace
Damper Clamp
Damper
Figure 11 - Attaching Flexible Gas Hose to Heater
Fitting
Flexible Gas Hose (if
allowed by local codes)
INSTALLATION
Installing Damper Clamp Accessory For Vented Operation
Installing Heater Base Assembly