Electrode Adjustment; Operating Instructions - Suburban SF-20 Installation Instructions Manual

OPERATING INSTRUCTIONS

WARNING! Do not operate furnace while vehicle is in motion or being
towed.
NOTE: During initial firing of this furnace, a burn-off of excess paint and oils
remaining from manufacturing process may cause "smoking" for 5 - 10 minutes.
1. Stop! Read Users Information Manual supplied with furnace.
2. Turn the manual valve (if so equipped) or the valve at the outside LP tank to the
"OFF" position. Do not force.
3. Set thermostat above room temperature to begin blower operation. A slight
delay will occur before the blower comes on. Allow blower to run for 5 minutes
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.
4. After 5 minutes, move thermostat lever below room temperature. Blower will
remain on. Wait approximately 2 minutes for blower to go off.
5. Open manual shut-off valve (if so equipped) or the valve at the outside LP
tank. Correct operating characteristics depend on the valve being positioned fully
open. Never attempt to operate with a valve partially closed. 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.
6. Set thermostat lever to desired setting. If set above room temperature, blower
will come on.
7. Allow 30 seconds for main burner to light after blower comes on. This furnace
is equipped with an ignition device which automatically lights the burner. Do not try
to light the burner by hand.
8. If burner does not light, repeat Steps 1 through 8.
9. 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 ignition. NOTE: If furnace should
lock out, the blower will go off in 5 minutes and remain off until unit is reset by
reactivating thermostat.
CAULK BEHIND VENT CAP AS SHOWN TO SEAL
BETWEEN EXHAUST AND INTAKE AND TO
PREVENT MOISTURE INSIDE FURNACE
COMPARTMENT. APPLY CAULKING GENEROUSLY
AROUND PERIMETER OF VENT CAP AND ACROSS
CENTER AS SHOWN. CENTER PUTTY STRIP IS
ESSENTIAL.
DETAIL "A"
OUTSIDE SKIN (PANEL)
TUBE, INTAKE AIR
WITH GASKET
VENT CAP AND
EXHAUST
FRONT
FURNACE CABINET
Figure 1
TO SHUT DOWN
1. Set the thermostat to lowest setting, then move lever to "OFF" position.
2. Turn manual shut off valve (if so equipped) to the "OFF" position. Do not force.

ELECTRODE ADJUSTMENT

For consistent ignition of the burner, it is important that the electrode be positioned
properly over the top of the burner. The electrode was set at the factory for proper
ignition and should not need further adjustment; however, if you should experience
inconsistent ignition, reposition electrode as follows:
Equipment needed:
flashlight
black felt-tip pen
needle-nose pliers
measuring tape
NOTE: Furnace must be removed. (See instructions for removing unit.)
1. Remove burner from combustion chamber by removing six (6) screws which
attach the burner to the chamber and air baffles (plates).
2. Locate the lance in relation to the burner ports for electrode positioning by:
a. Shine a flashlight into the burner venturi as illustrated. (Be sure flashlight
lens is against the end of the burner.)
b. Light will reflect off the lance in the venturi of the burner and shine
through a portion of the two (2) rolls of burner ports in the top of the
burner.
c. Using a black felt-tip pen, mark a line along top of burner 3/16" in back
of the lance and parallel with lance. Make an additional mark indicating
the center line of the lance. (See illustration.) Both marks will be used
later as reference marks; therefore, keep lines thin.
3. Reassemble the burner.
4. Adjust electrode so the electrode probe is positioned along the marked center
line of the burner lance and the tip of the electrode terminates 3/16" from the back
of the lance. (At the line marked in Step 2-c.) (See Figure 5.)
5. IMPORTANT: Be sure electrode probe maintains a 1/8" spark gap over the
burner as illustrated.
6. Reinstall the furnace into the cabinet following the instructions in the manual.
VENT CAP AND
EXHAUST TUBE
TUBE, AIR INTAKE
WITH GASKET
(2) 2 1/4"
DIA. HOLES
ELECTRICAL
CONNECTION
GAS CONNECTION
INSIDE WALL
6
SEE DETAIL "A"
REMOVABLE PANEL OF
COACH WALL MUST
SEAL WATER TIGHT
OUTSIDE SKIN (PANEL)
2" MAXIMUM WALL THICKNESS