
Model G3B Gas burner — Instruction manual
MNG3B Gas 041015
18
Maintenance/service procedures
Cleaning blower wheel
❏
Periodically inspect and clean the blower housing and wheel.
1. The best time to clean the blower housing and blower wheel is while
the ignition tube assembly is out of the air tube (see “Inspect ignitor and
ignition tube assembly”).
2. Remove the four #8-32 slotted screws in the motor mounting plate.
3. By pulling about 1 “ of slack in the motor wires from the control box, the
motor blower/wheel assembly can be pulled out and rotated to a good
position for cleaning the blower wheel.
4. With a small brush or pipe cleaner, remove all dirt from the blades in the
wheel.
5. With a clean rag, wipe out all the dirt from inside the blower housing.
6. Dirt that drops into the burner tube must be removed while the ignition
tube is out.
7. Replace the motor plate gasket with a new one.
8. Replace the motor blower wheel assembly, being very careful that the
gasket on the motor mounting plate makes a gas-tight seal against the
blower housing cover.
6. Maintenance and Service Procedures
(continued)
Replacing blower motor or wheel
Follow this procedure to replace motor or wheel.
1. Remove the four #8-32 screws in the motor mounting plate.
2. Pull about 1” of slack in the motor wires from the control box. Then pull
out and rotate the motor/blower wheel assembly.
3. Loosen Allen set screw in blower wheel hub and take the wheel off the
motor shaft.
4. Remove four #8-32 nuts holding motor to mounting plate. Be sure to take
the four nylon washer seals from the motor studs and save for the new
motor. Also remove the nylon motor bushing. Save the motor bushing for
use with the new motor.
5. Disconnect the motor wires from their wire nuts in the control panel,
keeping track of their locations.
6. Connect the new motor wires to their proper terminals.
7. Place the four nylon washer seals on the new motor studs and assemble
the motor plate to the motor using the four nuts.
8. Replace the blower wheel with about 1/16” of shaft protruding beyond
the hub.
9. Replace the motor plate gasket with a new one.
10. Replace the entire assembly, making sure that the gasket on the motor
plate makes a gas-tight seal against the blower housing cover.
Maintenance/service procedures
(continued)