Desa VSL18NT, VSL18PT installation manual Checking GAS Connections

INSTALLATION

Continued

For propane/LP gas, 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

the external regulator with the vent pointing down

as shown in Figure 15. Pointing the vent down

protects it from freezing rain or sleet.

CAUTION: Use only new,

black iron or steel pipe. Inter-

nally-tinned copper tubing may

be used in certain areas. Check

Install sediment trap in supply line as shown in Figure 16. 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.

Pressure	Heater
Regulator
	Cabinet

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 16).

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

going into pipe. Excess sealant in pipe could result

Test Gauge Connection*

3/8" NPT Pipe Nipple

Tee Joint

Reducer Bushing to 1/8" NPT

1/8" NPT

Plug Tap

Trap	Tee	Joint
	Pipe
Sediment
	Nipple
	Cap

Equipment

Shutoff

Valve *

3"

(7.6 cm)

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

Propane/LP From External Regulator (11" W.C. to 14" W.C. Pressure)

in clogged heater valves.
WARNING: Use pipe joint
sealant that is resistant to liquid
petroleum (LP) gas.
Propane/LP	External
Supply Tank
	Regulator
	Vent
	Pointing
	Down
Figure 15 - External Regulator With Vent
Pointing Down

Figure 16 - 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.

CHECKING GAS CONNECTIONS

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

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