resideo S8910U3000 Manuel D'installation page 14

S8910U3000
GAS LEAK TEST: Paint gas control gasket edges and all
pipe connections upstream of the gas control with a rich
soap and water solution. Bubbles indicate gas leaks.
Tighten the joints and screws or replace the component to
stop a gas leak. Recheck with soap and water solution.
Step 2: Verify control system ground.
The ignition module must share a common ground with
the main burner. The burner serves as the common
grounding area to assure reliable flame detection. If there
is not good metal-to-metal contact between the burner
and ground, run a lead from the burner to ground.
Step 3: Review normal operating sequence and module
specifications. See Operation and Application sections.
Step 4: Reset the ignition module.
a. Turn the thermostat or controller to the lowest
setting.
b. Turn on the system power.
c. Wait one minute.
As you do Steps 5 and 6, watch for points where operation
deviates from normal. Refer to Troubleshooting section to
correct the problem.
Step 5: Check the safety lockout operation.
a. Turn off the gas supply.
b. Set the thermostat or controller above the room
temperature to call for heat.
c. Watch for igniter warmup following prepurge.
Igniter starts to glow several seconds after it is
powered.
d. Time the length of time gas control is energized;
measure the time by connecting a voltmeter
across the gas valve terminals.
e. When configuring control for three ignition trials,
watch for the start of the 96-second between
trial purge, followed by a configured igniter war-
mup period and a second try for ignition. After a
third purge, warmup, and trial for ignition
sequence, the S8910U should lock out. The LED
displays a brief red flash. Refer to Table 6 for a
complete list of LED codes.
f. Open the manual gas control knob and make
sure no gas is flowing to the burner.
g. Set the thermostat below the room temperature
and wait one minute before continuing.
Step 6: Check normal operation.
a. Set the thermostat or the controller above the
room temperature to call for heat.
b. Observe the lightoff sequence and make sure the
main burner lights smoothly without flashback.
c. Make sure the burner operates smoothly without
floating, lifting, or flame rollout to the furnace
vestibule or heat buildup in the vestibule.
d. Test for a gas leak downstream of the gas control
if the piping has been disturbed.
GAS LEAK TEST: Paint the gas control gasket edges and
all pipe connections downstream of the gas control with a
rich soap and water solution. Bubbles indicate a gas leak.
Tighten the joints and screws or replace the component to
stop a gas leak. Recheck with soap and water solution.
34-00008EFS—03
e. Check the burner flame condition. The igniter-
sensor or sensor must be constantly immersed in
flame. Check the burner flame condition as
shown in Fig. 5. Do not relocate the hot surface
igniter or flame rod.
f. Turn the thermostat or controller below the room
temperature. Make sure the main burner and the
pilot flames go out.
WARNING
FIRE OR EXPLOSION HAZARD.
CAN CAUSE PROPERTY DAMAGE, SEVERE
INJURY, OR DEATH.
Improper location of the 120 Vac hot surface
igniter or any flame sensing rod can result in
appliance malfunction.
1.Never attempt to relocate the 120 Vac hot
surface igniter or the flame sensing rod from
the original position established by the
appliance manufacturer.
2.Be sure the 120 Vac hot surface igniter or the
flame sensing rod is replaced in exactly the
original position after removal for inspection,
service or replacement.
CHECK BURNER FLAME CONDITION
NOISY
LIFTING
FLAME
BURNER
WAVING
FLAME
SMALL
BLUE
FLAME
LAZY
YELLOW
FLAME
GOOD
RECTIFYING
FLAME
3/4 TO 1 IN. (19 TO 25 MM)
1/4 TO 1/2 IN. (6 TO 13 MM)
Fig. 5. Check burner flame condition.
OPERATION
The S8910U is a direct ignition control used with 120 Vac
timed warmup hot surface igniter. The control provides
operating control and shuts off all gas flow on ignition
failure or loss of main burner flame in central heat
furnaces and other heating appliances.
14
CHECK FOR:
• HIGH GAS PRESSURE
• EXCESS PRIMARY AIR
OR DRAFT
CHECK FOR:
• POOR DRAFT
• EXCESS DRAFT
• HIGH VELOCITY OR
SECONDARY AIR
INSTALL SHIELD IF NECESSARY
CHECK FOR:
• CLOGGED PORTS OR
ORIFICE FILTER
• WRONG SIZE ORIFICE
CHECK FOR LACK OF
AIR FROM:
• DIRTY PRIMARY
AIR OPENING
• LARGE PORTS
OR ORIFICES
M8446B