Vanguard Heating VN18A - Manual (Page 12)

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Tee Pipe Cap
Joint Nipple
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 Diameters
VN18A, VN18TA, VP16A, VP16TA, and
VP16ITA - 3/8" or greater
VN30A, VN30TA, VP26A, VP26TA, and
VP22ITA - 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).
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.
WARNING: Use pipe joint
sealant that is resistant to liquid
petroleum (LP) gas.
Install sediment trap in supply line as shown in
Figure 15. 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.
INSTALLATION
Continued
Tee Joint
Reducer
Bushing to
1/8" NPT
1/8" NPT
Plug Tap
* 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 33.
Figure 15 - Gas Connection
Pressure
Regulator
Test Gauge Connection*
Heater
Cabinet
Sediment Trap
Equipment
Shutoff
Valve *
3"
Min.
Natural Gas
From Gas
Meter (7" W.C.
to 10.5" W.C.
Pressure)
Propane/LP
From External
Regulator
(11" W.C. to 14"
W.C. Pressure)
Regulator
Bracket
Ground
Joint
Union
3/8" NPT
Pipe
Nipple
CHECKING GAS CONNECTIONS
WARNING: Test all gas pip-
ing and connections, internal
and external to unit, for leaks
after installing or servicing. Cor-
rect all leaks at once.
WARNING: Never use an
open flame to check for a leak.
Apply a noncorrosive leak de-
tection fluid to all joints. Bubbles
forming show a leak. Correct all
leaks at once.
CAUTION: For propane/LP
gas, make sure external regula-
tor has been installed between
propane/LP supply and heater.
See guidelines under
Connect-
ing to Gas Supply, page 11.