![background image](http://html1.mh-extra.com/html/desa/design-dynamics-vtd-18nv-jhb/design-dynamics-vtd-18nv-jhb_owners-operation-and-installation-manual_2486339008.webp)
www.desatech.com
114370-02C
8
For propane/LP units, the installer must supply
an external regulator. The external regulator will
reduce incoming gas pressure. You must reduce
incoming gas pressure to between 11 and 14 inches
of water. If you do not reduce incoming gas pres
-
sure, regulator damage could occur. Install external
regulator with the vent pointing down as shown in
Figure 6. Pointing the vent down protects it from
freezing rain or sleet.
CAUTION: Use only new, black
iron or steel pipe. Internally-tinned
copper tubing may be used in
certain areas. Check your local
codes. Use pipe of 1/2" diameter
or greater to allow proper gas vol-
ume to heater. If pipe is too small,
undue loss of volume will occur.
Installation must include an equipment shutoff
valve, union and plugged 1/8" NPT tap. Locate
NPT tap within reach for test gauge hook up.
NPT tap must be upstream from log set (see
Figure 7).
IMPORTANT:
Install equipment shutoff valve
in an accessible location. The equipment shutoff
valve is for turning on or shutting off the gas to
the appliance.
Check your building codes for any special re
-
quirements for locating equipment shutoff valve
to fireplaces.
Apply pipe joint sealant lightly to male NPT
threads. This will prevent excess sealant from
going into pipe. Excess sealant in pipe could result
in clogged heater valves.
Figure 7 - Gas Connection
* Purchase the optional CSA design-certified shutoff
valve from your dealer. See
Accessories
, page 17.
** Minimum inlet pressure for purpose of input
adjustment.
Approved
Flexible Gas
Hose (If allowed
by local codes)
CSA Design-Certified
Equipment Shutoff
Valve with 1/8" NPT
Tap*
Propane/LP Gas
From External
Regulator (11"
W.C.** to 14" W.C.
Natural Gas
From Gas Meter
(5" W.C.** to 10.5"
W.C. Pressure)
3" Min.
Pipe Cap Tee
Nipple
Joint
Sediment Trap
INSTALLATION
Continued
WARNING: Use pipe joint
sealant that is resistant to liquid
petroleum (LP) gas.
We recommend that you install a sediment trap in
supply line as shown in Figure 7. Locate sediment
trap where it is within reach for cleaning. Install in
piping system between fuel supply and appliance.
Locate sediment trap where trapped matter is not
likely to freeze. A sediment trap traps moisture and
contaminants. This keeps them from going into
heater controls. If sediment trap is not installed or
is installed wrong, heater may not run properly.
CAUTION: Avoid damage to
gas control. Hold gas control
with wrench when connecting it
to gas piping and/or fittings.
Figure 6 - External Regulator with Vent
Pointing Down
Propane/LP
Tank
External
Regulator with
Vent Pointing
Down