Desa LMFP33NR(A) - Manual (Page 14)

www.desatech.com 111604-01K 14
For propane/LP units, 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
external regulator with the vent pointing down
as shown in Figure 19. 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
your local codes. Use pipe of
1/2" diameter or greater to allow
proper gas volume to fireplace.
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 fireplace (see Figure 20).
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.
Check your building codes for any special re-
quirements for locating equipment shutoff valve
to fireplaces.
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
fireplace valves. Never use sealant on flare threads.
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 20. Locate sediment
trap where it is within reach for cleaning. Install in
piping system between fuel supply and fireplace.
Locate sediment trap where trapped matter is not
likely to freeze. A sediment trap traps moisture and
contaminants. This keeps them from going into fire-
place gas controls. If sediment trap is not installed or
is installed wrong, fireplace may not run properly.
INSTALLATION
Continued
Figure 19 - External Regulator on
Propane/LP Supply Tank with Vent
Pointing Down
External
Regulator
Vent Pointing Down
Propane/LP
Supply Tank
Figure 20 - Gas Connection
* Purchase the optional CSA design-certified
equipment shutoff valve from your dealer. See
Accessories , page 34.
** Minimum inlet pressure for purpose of input
adjustment.
Sediment Trap
3" Minimum
Cap Pipe Tee
Nipple Joint
CSA Design-Certified Equipment Shutoff
Valve With 1/8" NPT Tap*
Natural Gas
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)