Desa VTDMV18NA Electric Heater User Manual


 
www.desatech.com
114926-01B
8
INSTALLATION
Continued
CAUTION: Use only new, black
iron or steel pipe. Internally-tinned
copper tubing may be used in
certain areas. Check your local
codes. Use pipe of 1/2" diameter
or greater to allow proper gas vol-
ume to heater. If pipe is too small,
undue loss of volume will occur.
Installation must include an 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 log set (see Figure 7).
IMPORTANT: Install 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.
WARNING: Use pipe joint
sealant that is resistant to liquid
petroleum (LP) gas.
We recommend that you install a sediment trap in
supply line as shown in Figure 7. Locate sediment
trap where it is within reach for cleaning. Install in
piping system between fuel supply and appliance.
Figure 7 - Gas Connection
* Purchase the optional CSA design-certified shutoff
valve from your dealer. See Accessories, page 17.
** Minimum inlet pressure for purpose of input
adjustment.
Approved Flexible
Gas Hose (If
allowed by local
codes)
CSA Design-Certified
Equipment Shutoff
Valve with 1/8" NPT
Tap*
Natural
From Gas
Meter (5" W.C.**
to 10.5" W.C.
Pressure)
Propane/LP
From External
Regulator (11"
W.C.** to 14"
W.C. Pressure)
3" Min.
Pipe Cap Tee
Nipple Joint
CHECKING GAS CONNECTIONS
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: Make sure exter-
nal regulator has been installed
between propane/LP supply
and appliance. See guidelines
under Connecting to Gas Sup
-
ply, page 7.
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 (control valve) and equipment shutoff
valve from gas supply piping system. Pressures
in excess of 1/2 psig will damage control valve.
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 compressed air.
4. Check all joints of gas supply piping system.
Apply noncorrosive leak detection fluid to all
joints. Bubbles forming show a leak.
5. Correct all leaks at once.
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.
CAUTION: Avoid damage to
gas control. Hold gas control
with wrench when connecting it
to gas piping and/or fittings.
Sedament Trap