Desa LSL18PT, LSL18NT, VSL18PT, VSL18NT installation manual Installation, ing to Gas Supply, page

INSTALLATION
Continued
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
large enough diameter to allow
proper gas volume to heater. If
pipe is too small, undue loss of
volume will occur.
Typical Inlet Pipe Diameter - 3/8" (9.5 mm)
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 14).
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.
Pressure	Heater
Regulator	Cabinet

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.

Install sediment trap in supply line as shown in Figure 14. Locate sediment trap where it is within reach for cleaning. 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.

IMPORTANT: Hold the pressure regulator with wrench when connecting it to gas piping and/or fittings. Do not over tighten pipe connection to regulator. The regulator body could be damaged.

CHECKING GAS CONNECTIONS

WARNING: Test all gas piping and connections, internal and external to unit, for leaks after installing or servicing. Correct

Gauge Connection*

3/8" NPT Pipe Nipple

Tee Joint

Reducer Bushing to 1/8" NPT

1/8" NPT

Plug Tap

Ground Joint

Union

Equipment

Shutoff

Valve *

all leaks at once.

WARNING: Never use an open flame to check for a leak. Apply a noncorrosive leak detec- tion fluid to all joints. Bubbles forming show a leak. Correct all leaks at once.

Test

TrapSediment

Tee Joint

Pipe

Nipple

Cap

3"

(7.6 cm)

Min. Natural Gas

From Gas Meter (4" W.C. to 10.5" W.C. Pressure)

Propane/LP

CAUTION: For propane/LP gas, make sure external regula- tor has been installed between propane/LP supply and heater. See guidelines under Connect-

From External Regulator

(11" W.C. to 14" W.C.

Pressure)

Figure 14 - Gas Connection

*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 23.

ing to Gas Supply, page 11.

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