Desa GN30T Safety Information And Installation Manual page 12

INSTALLATION
Continued
CONNECTING TO GAS SUPPLY
WARNING: This appliance
requires a 3/8" 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.
WARNING: For natural gas,
never connect heater to private
(non-utility) gas wells. This gas is
commonly known as wellhead gas.
IMPORTANT: For natural gas, check gas line
pressure before connecting heater to gas line. Gas
line pressure must be no greater than 14 inches of
water. If gas line pressure is higher, heater regula-
tor damage could occur.
CAUTION: For propane/LP
gas, never connect heater directly
to the propane/LP supply. This
heater requires an external regu-
lator (not supplied). Install the
external regulator between the
heater and propane/LP supply.
For propane/LP gas, the installer must supply an
external regulator. The external regulator will re-
duce incoming gas pressure. You must reduce in-
coming 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
the external regulator with the vent pointing down
as shown in Figure 14. Pointing the vent down
protects it from freezing rain or sleet.
12
black iron or steel pipe. Inter-
nally-tinned copper tubing may
be used in certain areas. Check
your local codes. Use pipe of
large enough diameter to allow
proper gas volume to heater. If
pipe is too small, undue loss of
volume will occur.
20,000 Btu/Hr Models - 3/8" or greater
30,000 Btu/Hr Models - 1/2" or greater
Installation must include 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 15, page 13).
IMPORTANT: Install an equipment shutoff valve
in an accessible location. The equipment shutoff
valve is for turning on or shutting off the gas to
the appliance.
Apply pipe joint sealant lightly to male NPT
threads. This will prevent excess sealant from go-
ing into pipe. Excess sealant in pipe could result
in clogged heater valves.
sealant that is resistant to liquid
petroleum (LP) gas.
Install sediment trap in supply line as shown in
Figure 15, page 13. Locate sediment trap where it
is within reach for cleaning. Locate sediment trap
where trapped matter is not likely to freeze. A sedi-
ment trap traps moisture and contaminants. This
keeps them from going into heater controls. If sedi-
ment trap is not installed or is installed wrong,
heater may not run properly.
Propane/LP
Supply Tank
Figure 14 - External Regulator With Vent
www.desatech.com
CAUTION: Use only new,
Typical Inlet Pipe Diameters
WARNING: Use pipe joint
External Regulator
Pointing Down
Vent
Pointing
Down
107884-01H