![background image](http://html1.mh-extra.com/html/desa/gwrn18/gwrn18_safety-information-and-installation-manual_2485898011.webp)
107885-01D
For more information, visit www.desatech.com
For more information, visit www.desatech.com
11
11
INSTALLATION
Continued
INSTALLATION
Connecting To Gas Supply (Cont.)
Checking Gas Connections
Typical Inlet Pipe Diameters
GWRP16(T), GWRN18(T) - 3/8" or greater
GWRP26(T), GWRN30(T) - 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 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.
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.
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.
WARNING: Use pipe joint sealant that is resistant
to liquid petroleum (LP) gas.
* 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 26.
Figure 14 - Gas Connection
Pressure Regulator
Tee Joint
Reducer
Bushing to
1/8" NPT
1/8" NPT
Plug Tap
Test
Gauge
Con-
nection*
Tee Joint
Pipe Nipple
Cap
Heater Cabinet
Sediment
Trap
Equipment
Shutoff Valve *
3"
Minimum
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
3/8" NPT Pipe Nipple
Ground Joint Union
WARNING: Test all gas piping and connections
for leaks after installing or servicing. Correct all leaks
at once.
WARNING: Never use an open flame to check for
a leak. Apply a noncorrosive leak detection fluid to all
joints. Bubbles forming show a leak. Correct all leaks
at once.
CAUTION: For propane/LP gas, make sure exter-
nal regulator has been installed between propane/LP
supply and heater. See guidelines under
Connecting
to Gas Supply, page 10.
Pressure Testing Gas Supply Piping System
Test Pressures In Excess Of 1/2 PSIG (3.5 kPa)
1.
Disconnect appliance with its appliance main gas valve (con-
trol valve) and equipment shutoff valve from gas supply pip-
ing system. Pressures in excess of 1/2 psig will damage heater
regulator.
2.
Cap off open end of gas pipe where equipment shutoff valve
was connected.
3.
Pressurize supply piping system by either opening propane/LP
supply tank valve for propane/LP gas or opening main gas valve
located on or near gas meter for natural gas, or using com-
pressed air.
4.
Check all joints of gas supply piping system. Apply a noncorrosive
leak detection fluid to all joints. Bubbles forming show a leak.
5.
Correct all leaks at once.
6.
Reconnect heater and equipment shutoff valve to gas supply.
Check reconnected fittings for leaks.
CHECKING GAS CONNECTIONS