Combustion Blower And Burner Removal/ Installation; Combustion Blower/ Burner Removal; Combustion Blower/ Burner Installation - A.O. Smith Cyclone XL 100 Series Service Handbook

COMBUSTION BLOWER AND BURNER REMOVAL/ INSTALLATION

COMBUSTION BLOWER AND BURNER REMOVAL/ INSTALLATION
Refer to the Combustion Blower & Burner Assembly, Heater Top View images in this Service Handbook and the Instruction Manual
supplied with the heater for heater component locations.

COMBUSTION BLOWER/ BURNER REMOVAL

1. Turn the water heater's Enable/Disable switch to the "Disable" Position.
2. Turn off the electrical circuit breaker that serves the water heater.
3. Close the Main Gas Shut Off Valve serving the water heater.
4. Remove the water heater's top plastic cover, UIM, and lower plastic cover.
5. Disconnect the supply gas line to the water heater on the heater side of the Main Gas Shut Off Valve.
6. If the water heater has been installed in a Direct Vent configuration, disconnect the Blocked Air Intake Switch sensing tube (light blue
soft tubing) from the Air Intake Pipe Assembly and disconnect the intake air pipe at the intake air connection on the water heater by
loosening the hose clamp closest to the Venturi and remove the Intake Air Assembly.
7. If the water heater has been installed in a Non-Direct Vent configuration, disconnect the Blocked Air Intake Switch sensing tube (light
blue soft tubing) from the Air Intake Pipe Assembly and disconnect the intake air pipe at the intake air connection on the water heater
by loosening the hose clamp closest to the Venturi and remove the Intake Air Assembly.
8. Unplug the ignition cable from the spark igniter and the yellow wire from the Flame Sensor.
9. Disconnect the 3-Pin and 5-Pin plugs from the Combustion Blower Assembly.
10. Disconnect the 24 Volt power wires to the Gas Control Valve at the two spade connectors in the wiring harness to the valve.
11. Using a socket wrench with a ½" deep well socket, remove the ten nuts from the studs holding the burner plate in place.
12. Slide the three burner ground wire eyelet connectors up and off of the studs.
Note: These ground wires must be reinstalled when reinstalling the Burner Assembly.
13. Ensure there are not any loose parts, tools, screws, or objects of any kind on top of the water heater before removing the Burner
Assembly as these objects could fall into the heat exchanger.
14. Carefully lift the Burner/Blower Assembly straight up and out of the heater exchanger opening.
15. Refer to the Flame Sensor and Spark Igniter sections of this Service Handbook for their servicing specifications.

COMBUSTION BLOWER/ BURNER INSTALLATION

1. Install new white fiber Burner Plate gaskets before re-installing the Blower/Burner Assembly.
2. To re-install the Burner Assembly follow the steps for removal in reverse order.
3. Do not over-tighten the ½" nuts.
4. Connect the supply gas line to the water heater on the heater side of the Main Gas Shut Off Valve.
5. Slowly open the Main Gas Shut Off Valve serving the water heater.
6. Turn on the electrical circuit breaker that serves the water heater.
7. Turn the water heater's Enable/Disable switch to the "Enable" Position.
8. Operate heater through at least one complete heating cycle to verify it is operating properly.
31