Atwood Mobile Products LLC highly recommends the use of an
electronic (solid-state) converter with clean power output. This will
assure extended life of the electronic controls and motor beyond
typical linear converter applications.
Conductor Sizing Table 6
– Maximum 10% Voltage Drop – (12 VDC)
Current draw (AMPS)
Max. Length of SAE conductor (in feet) from source to
This furnace designed for negative ground 12 volts DC only. DO NOT
attempt to alter furnace for a positive ground system or connect the
furnace directly to 120 volts, AC. Damage to furnace components will
occur and warranty will be voided.
Use a minimum of 18 GA wire to minimize voltage drop. Furnace must
be installed so electrical components are protected from water. To
make electrical connections see wiring diagrams.
For best furnace performance when power supply is from a converter
equipped with a charging port, wire converter to furnace parallel with
battery. This provides consistent voltage to furnace, increasing
component life, filtering power surges and AC spikes.
All units are supplied with a power switch which when turned off during
servicing will remove power through furnace wiring. Switch must be in
the ON position for furnace to operate.
Route wiring to the furnace.
Connect red wire to positive +12VDC of power supply.
Connect black wire to ground of power supply.
Connect Thermostat +12 VDC blue wire to power supply using 22-18
GA stranded wire.
Connect Thermostat blue wire to the thermostat lead using minimum
22-18 GA stranded wire.
All wiring shall be installed so the electrical components are protected
Thermostats not supplied. Purchase a thermostat rated for 12 VDC or
24 VAC, Minimum 1 AMP rating see Atwood parts list for thermostat
Be sure all electrical power to the furnace is disconnected.
The thermostats are very sensitive, HANDLE WITH CARE AT ALL
Pick a dry area where air circulation is good.
Do not install the thermostat where there are unusual heating
conditions: such as direct sunlight, heat producing appliances
(television, radio, wall lamp, etc.) or a furnace or air conditioner output
Locate thermostat 48" to 54" above main living area floor on an
INTERIOR wall when possible
EXTERIOR wall location must have a 3/4" spacer between thermostat
and exterior wall.
Follow manufacture's installation instructions provided with thermostat.
FIRE OR EXPLOSION
Do not operate furnace while vehicle is in motion or being
During initial firing of this furnace, a burn-off of excess oils remaining
from manufacturing process may cause smoking or fumes for 5-10
NOTE: if furnace should lock out, the blower will go off in 90 seconds
and remain off until unit is reset by reactivating the thermostat.
Stop! Read Users Information Manual supplied with
Turn the manual valve (if so equipped) or the valve at the outside LP
tank to the "OFF"" position. Do NOT force. NOTE: This furnace is
equipped with a valve shut-off switch with switch in "OFF" position.
Gas will not flow to burner nor will the furnace operate. Turn switch to
Set thermostat above room temperature to begin blower operation. A
slight delay will occur before the blower comes on. Allow blower to run
for 1 minute for combustion chamber purge cycle. If blower does not
come on or stops before ignition cycle, go to shut down and contact
your dealer or a local recreational vehicle service agency.
After 1 minute, move thermostat lever below room temperature. Blower
will remain on. Wait approximately 2 minutes for blower to go off.
Open manual shut-off valve (if so equipped) or the valve at the outside
LP tank. Correct operation characteristics depend on the valve being
positioned fully open. Never attempt to operate with a valve partially
Set thermostat lever to desired setting. If set above room temperature,
blower will come on.
Allow 30 seconds for main burner to light after blower comes on. This
furnace is equipped with an ignition device that automatically lights the
burner. DO NOT try to light the burner by hand.
If burner does not light, repeat Steps 1 through six.
If after three (3) attempts with no ignition, go to shut down and contact
your dealer or a local recreational vehicle service agency. Do not
continue to cycle furnace through thermostat in an attempt to get
TO SHUT DOWN
Set the thermostat to lowest setting, then move lever to "OFF" position.
Turn manual shut off valve (if so equipped) to the "OFF" position. Do
PROPANE GAS PRESSURE TEST
The furnace and any individual shut-off valve must be disconnected
from gas supply piping system during any pressure testing of system at
test pressures of more than 1/2" PSI.
Before furnace is connected, piping systems must be tested to be leak
free. The test must maintain air pressure of a least 6" of mercury or 3"
PSI for at least 10 minutes.
The entire piping system must be maintained within a range of 10 to
14" WC when all appliances are in operation. Test gas connections for
leakage with a leak test solution.
Ignition control diagnostic codes
The following charts give the diagnostic codes given by the ignition
control when faults are present.
A soft lockout is a timed condition that will make additional
attempts to correct the problem. A hard lookout requires resetting
of the thermostat or turning the power switch off, then back on.
Internal Circuit Board
Flame Sense Fault
Ignition Lockout Fault
Standard 3 tries for Ignition Controls
Steady On, No Flashing
1-Flash With 3-Second
2-Flashes With 3-Second
3-Flashes With 3-Second
Soft (after 1 hr)