Desa VUL18NR Owner's Operation And Installation Manual page 13

2. State or local codes do not permit vent-
free operation.
3. You prefer vented operation.
If reasons number 1 or 2 apply to you, you
must permanently open chimney flue damper.
You must install the damper clamp accessory
(to order, see Accessories, page 40). 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 open-
ing will be maintained at all times.
Area of Various Standard Round Flues
Diameter
5"
6"
7"
8"
Chimney Height
6' to 15'
15' to 30'
Damper
Clamp
Damper
Clamp
Damper
Masonry Fireplace
Figure 10 - Attaching Damper Clamp
122001-01C
INSTALLATION
Area
20 sq. inches
29 sq. inches
39 sq. inches
51 sq. inches
Minimum Permanent
Flue Opening
39 sq. inches
29 sq. inches
Damper
Damper
Manufactured Fireplace
www.desatech.com
Continued
INSTALLING HEATER bASE
ASSEMbLY
WARNING: You must secure
this heater to fireplace floor. If
not, heater will move when you
adjust controls. Moving heater
may cause a gas leak.
WARNING: If installing in a
sunken fireplace, special 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
controls being damaged. Raise
fireplace floor with noncombus-
tible material. Make sure material
is secure.
CAUTION: Do not pick up
heater base assembly by burn-
ers. This could damage heater.
Only handle base assembly by
grates.
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 33.
Installation Items Needed
• hardware package (provided with heater)
• approved flexible gas hose and fittings (not
provided) (if allowed by local codes)
• sealant (resistant to propane/LP gas, not
provided)
• electric drill with 3/16" masonry drill bit
Note: Install optional Receiver and Hand-Held
Remote Control Kit (see Accessories, page
40) before installing gas log heater (Remote-
Ready Models Only). See installation instruc-
tions included with the kit.
13