![background image](http://html.mh-extra.com/html/desa/cdr3924nt/cdr3924nt_owners-operation-and-installation-manual_2485759012.webp)
www.desatech.com
113183-01B
12
INSTALLATION
Continued
CONNECTING TO GAS SUPPLY
WARNING: This appliance
requires a 1/2" NPT (National
Pipe Thread) inlet connection to
the pressure regulator.
WARNING: A qualified ser-
vice person must connect heater
to gas supply. Follow all local
codes.
CAUTION: For propane/LP
gas, never connect heater di-
rectly to the propane/LP supply.
This heater requires an external
regulator (not supplied). Install
the external regulator between the
heater and propane/LP supply.
Installation Items Needed
Before installing heater, make sure you have the
items listed below.
• external regulator for propane/LP only (sup-
plied by installer)
• piping (check local codes)
• sealant (resistant to propane/LP gas)
• equipment shutoff valve *
• test gauge connection *
• sediment trap
• tee joint
• pipe wrench
* A CSA design-certified equipment shutoff valve
with 1/8" NPT tap is an acceptable alternative to
test gauge connection. Purchase the optional CSA
design-certified equipment shutoff valve from your
dealer. See
Accessories
, page 25.
For propane/LP only, 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, heater regulator damage could occur. Install
external regulator with the vent pointing down
as shown in Figure 12. Pointing the vent down
protects it from freezing rain or sleet.
WARNING: For natural
gas, never connect heater to
private (non-utility) gas wells.
This gas is commonly known
as wellhead gas.
CAUTION: Use only new,
black iron or steel pipe. Inter-
nally-tinned copper tubing may
be used in certain areas. Check
your local codes. Use pipe of
1/2" inside diameter or greater
to allow proper gas volume 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 heater (see Figure 13,
page 13).
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 building codes for any special require-
ments 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.
WARNING: Use pipe joint
sealant that is resistant to liquid
petroleum (LP) gas.
Propane/LP
Supply Tank
External
Regulator
Figure 12 - External Regulator With Vent
Pointing Down
Vent
Pointing
Down