Operation - Honeywell Y8610U Product Data

If the desired outlet gas pressure or gas flow rate
cannot be achieved by adjusting the gas control, check
the gas control inlet pressure using a manometer at the
inlet pressure tap. If the inlet pressure is in the normal
range, replace the gas control; otherwise, take the
necessary steps to provide proper gas pressure to the
gas control.
STEP 6: Adjust Pilot Flame.
The pilot flame should envelop 3/8 to 1/2 in. (10 to 13 mm) of
the ground rod and tip of the igniter-sensor. See Fig. 17 to
adjust the pilot flame.
IGNITER-SENOR TIP IN PILOT FLAME
PROPER FLAME
ADJUSTMENT
PILOT GAS
TUBING
Fig. 17. Proper flame adjustment.
Remove the pilot adjustment cover screw. See Fig. 3.
Turn the inner adjustment screw clockwise to decrease
or counterclockwise to increase the pilot flame.
Always replace the cover screw after adjustment and
tighten firmly.
STEP 7: Check Other System Components
• On Furnaces: Make sure the limit controller and fan
controller are operating in accordance with the appliance
manufacturer instructions.
• On Boilers: Make sure the circulating water pumps, low
water cutoffs, automatic feed controllers, pressure and
temperature limit controllers, and relief valves are
operating in accordance with the appliance manufacturer
recommendations.
STEP 8: Check Normal Operation
• Set the thermostat or controller above the room
temperature to call for heat.
• Make sure the pilot lights smoothly when the gas reaches
the pilot burner.
GROUND ROD
ELECTRODE SCREW
IGNITER-SENSOR
ASSEMBLY
IGNITION
CABLE
STUD
TERMINAL M4677
Y8610U INTERMITTENT PILOT RETROFIT KIT
• Make sure the main burner lights smoothly without
flashback.
• Make sure the main burner operates smoothly without
floating, lifting, or flame rollout to the furnace vestibule or
heat buildup in the vestibule.
• If the gas line has been disturbed, complete the Gas Leak
Test following Step 1.
• Turn the thermostat or controller below the room
temperature. Make sure the main burner and pilot flames
go out.

OPERATION

System operation is divided into two stages:
1. Trial for ignition.
2. Main burner operation.
See Fig. 18 for the normal operating sequence.
Trial for Ignition
Pilot Ignition
Following the call for heat, the module energizes the first
main valve operator. The first main valve opens, which allows
gas to flow to the pilot burner. At the same time, the electronic
spark generator in the module produces a high voltage spark
pulse output. The voltage generates a spark at the igniter-
sensor that lights the pilot.
If the pilot does not light, or the pilot flame current is not at
least 1.0 uA and steady, the module can not energize the
second (main) valve and the main burner can not light. After
90 seconds maximum, the system shuts off and the pilot
valve closes; trial for ignition restarts after a minimum of five
minutes (six minutes nominal). Ignition, shutoff, and wait
sequence repeats until pilot lights or call for heat ends.
Main Burner Operation
When the pilot flame is established, a flame rectification
circuit is completed between the sensor and burner ground.
The flame sensing circuit in the module detects the flame
current, shuts off the spark generator and energizes the
second main valve operator. The second main valve opens
and gas flows to the main burner, where it is ignited by the
pilot burner.
When the call for heat ends, both valve operators are de-
energized, and both valves in the gas control close.
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