Dometic DFSD12 - Connecting The Gas

20
INSTALLATION
F. Connecting The Gas
FIRE OR EXPLOSION HAZ ARD. Failure to obey the following warnings could result in property damage, serious
injury, or death:
• Install gas connections in compliance with the applicable supplemental directives listed in this manual. Refer to
“C. Supplemental Directives” on page 2.
• NEVER use an open flame to check for gas leaks. Use a commercially available soap solution made specifically for the
detection of leaks to check all connections, as specified in these instructions.
• Should the gas supply fail to shut off or if overheating occurs, shut off the gas valve to the Furnace before shutting off the
electrical supply.
• Do NOT put sealing compound on flare fittings.
FIG.1
Extended
Manifold
(Rear)
Gas Connection
Grommet
Plug

An extended manifold is used in this example; however,
the use of tubing or other variations to connect the gas is
acceptable.
• Treat all male pipe threads, other than flare fittings, with a
sealing compound resistant to a chemical reaction with LP
gas.
• Remove the grommet plug from the Furnace and install on
the gas line.
• Insert the gas line through the hole in the top of the casing.
• Connect the gas line to the fitting located on the valve. If
the Furnace is supplied with an extended manifold,
connect the gas line at the rear of the Furnace.
• Reinstall the grommet plug on the casing, as it is a required
air seal. DO NOT CUT.
• Use two wrenches to hold the valve and flare nut, and
tighten the flare nut over the gas line.
• Torque the fitting to 20–22 . lbs. Do NOT twist the valve
out of position when tightening the gas line.

For DFLA35 and DFLA40 models only, a gas conversion kit
is included with your Furnace. To convert the Furnace gas
type, proceed to “G. Converting The Furnace Gas Type” on
page 21.
LP Gas Pressure Test

Read BEFORE proceeding:
• Test all piping systems BEFORE connecting the
Furnace.
• Disconnect the Furnace and any individual shut-off
valves from the gas supply piping system when
pressure testing the system at pressures of more than
1/2" PSI.
• If local codes allow the use of a flexible gas appliance
connector, do NOT use a connector which has
previously serviced another gas appliance.
• For gas conversions only, a 1/8" NPT plug is provided
upstream of the gas connections for checking the gas
pressure.
• Perform an air pressure test on the piping system. The test
must maintain an air pressure of a least 6" of mercury or
3 PSI for at least 10 minutes.
• Adjust the piping system to maintain the minimum gas
supply pressure listed on the rating plate, when all
appliances are in operation.
• Test gas connections for leakage with a commercially
available soap solution made specifically for the detection
of leaks.