S8610U UNIVERSAL INTERMITTENT PILOT GAS IGNITION CONTROL
69-1955
16
Step 1: Perform Visual Inspection.
1.
With power off, make sure all wiring connections
are clean and tight.
2.
Turn on power to appliance and ignition control
module.
3.
Open manual shutoff valves in the gas line to the
appliance.
4.
Perform a gas leak test ahead of gas control if pip-
ing has been disturbed.
GAS LEAK TEST:
Paint the 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
component to stop gas leak. Recheck with soap
and water solution.
Step 2: Verify Ignition Control System Ground.
The igniter, flame sensor, and ignition control module
must share a common ground with the pilot burner. Use
thermoplastic insulated wire with a minimum rating of
221°F (105°C) for the ground wire; asbestos insulation is
not acceptable. If the temperature at the wire could
exceed 221°F (105°C), use a shield to protect the wire
from radiant heat generated by the burner. Connect the
ground wire as follows:
1.
Fit one end of the ground wire with a female 1/4 in.
quick-connect terminal and connect it to the male
quick-connect GND (BURNER) terminal on the igni-
tion control module.
2.
Strip the other end of the wire and fasten it under
the igniter bracket mounting screw. If necessary,
use a shield to protect the ground wire from radiant
heat.
3.
The burner serves as the common grounding area.
If there is not good metal-to-metal contact between
the burner and ground, run a lead from the burner
to ground.
NOTE: Earth ground is not required.
Step 3: Review Normal Operating Sequence and
Ignition Control Module Specifications.
— See “Operation” section on this page and “Specifi-
Step 4: Reset the Ignition Control Module.
1.
Turn the thermostat to its lowest setting.
2.
Wait one minute.
As you perform the remaining steps, watch for points
where operation deviates from normal. To correct
problems, refer to the “Troubleshooting Guide” on
page 21.
Step 5: Check Safety Shutoff Operation.
1.
Turn gas supply off.
2.
Set thermostat or controller above room tempera-
ture to “Call for Heat.”
3.
Watch for spark at pilot burner. Time spark from
start to shutoff. Spark should shut off after 15 or 90
seconds (selectable with Dip Switch SW1). See
device label and “Settings and Adjustments” on
page 15.
4.
Wait 5 minutes. Ignition sequence should start
again followed by shutoff.
5.
Open manual gas cock and make sure no gas is
flowing to pilot or main burner.
6.
Set thermostat below room temperature and wait
one minute before continuing.
Step 6: Check Normal Operation.
1.
Turn on the gas supply.
2.
Set thermostat or controller above room tempera-
ture to “Call for Heat.”
3.
Make sure pilot lights smoothly when gas reaches
the pilot burner.
4.
Make sure main burner lights smoothly without
flashback.
5.
Make sure burner operates smoothly without float-
ing, lifting, or flame rollout to the furnace vestibule
or heat buildup in the vestibule.
6.
Perform a gas leak test in the appliance.
GAS LEAK TEST:
Paint the gas control gasket edges and all pipe
connections downstream of the gas control,
including the pilot tubing connections, with a rich
soap and water solution. Bubbles indicate gas
leaks. Tighten the joints and screws or replace
component to stop gas leak. Recheck with soap
and water solution.
7.
Turn the thermostat or controller below the room
temperature. Make sure the main burner and pilot
flames go out.
OPERATION
Fig. 8 on page 17 summarizes the normal operating
sequence for installations with and without vent dampers.
The ignition control module’s operation can be
conveniently divided into two phases.
• Trial for pilot ignition
• Main burner operation
Trial for Pilot Ignition
On a “Call for Heat”, the ignition control module energizes
the spark source and the pilot valve relay simultaneously.
The pilot valve opens, allowing gas to flow to the pilot
burner for the ignition trial time. The spark lights the pilot
flame when pilot gas is present. A flame rectification
circuit confirms the presence of the pilot flame, shuts off
the spark source, and energizes the main valve relay.
The ignition control module uses a two-level pilot flame
proving sequence. When a sufficient flame current is
sensed, the spark is turned OFF. However, the pilot flame
must generate a higher level of flame current to energize
the main valve. This approach assures a stable pilot flame
to support reliable burner lightoff. If the pilot flame is weak
or unstable, the spark may turn back ON. However, the
trial for pilot ignition will not exceed the stated ignition trial
time.
Main Burner Operation
When the main valve opens, gas flows to the main burner
where it is lit by the pilot flame. There is a short flame
stabilization period as the main valve opens to allow the
pilot flame to stabilize as the main gas lights. The system
is now in the run mode with the presence of the pilot flame
continuously monitored by the flame rectification circuit. If
the pilot flame goes out, the ignition control module
senses loss of pilot flame and shuts off both the pilot valve
relay and the main valve relay. Flow of gas to pilot and
main burners stops as the valves close (100% shutoff).