Form O-Y, PN 273647R5, Page 40
Vent Maintenance
Remove dirt and grease from the venter motor housing. The venter motor is perma-
nently lubricated; do not lubricate. Carefully clean the venter wheel assembly, being
cautious not to bend the wheel.
Check the vent at least once a year. Clean the terminal screen. If equipped with
optional vertical vent extension, inspection should include all joints, seams, and the
terminal. Replace any defective parts.
Venter Speed Board Options AG73 and AG74
- Modulating gas controls have a
proprietary electronically controlled venter system that provides the required volume
of combustion air and correct gas pressure to maintain thermal efficiency during
periods of modulation. Change of venter speed is controlled by an electronic board
located on the heat section control panel (See
FIGURE 23,
page 32). The venter sys-
tem always operates at high speed during pre-purge and post-purge periods. Speed
selection occurs after there is a call for burner ignition.
Venter Speed Board
5.3 Vent
Maintenance
and Operation
Maintenance
Instructions for the
Venter Motor and
Wheel
FIGURE 28 - Venter
Wheel Position on
the Shaft (High
Efficiency Models)
Remove dirt and grease from the motor casing, the venter housing, pressure sensing
tap, and the venter wheel. Venter motor bearings are permanently lubricated.
Follow these instructions for replacement of the venter motor and wheel assembly.
Keep all hardware removed to be used in re-assembling and installing the replace-
ment parts.
1.
Turn off the gas and disconnect the electric power.
2.
Open the burner/control compartment door panel.
3.
Disconnect the two or three venter motor wires at the DSI control or the venter
speed control board, capacitor wires at the capacitor (if applicable), and ground
screw (located on the control panel).
4.
On high efficiency (90%) condensing heat section
, holding the venter motor,
remove the screws that attach the venter motor mounting plate to the venter
housing. Remove the motor and wheel assembly from the heater.
On standard efficiency (80%) non-condensing heat section
, remove the venter
housing assembly by removing the screws that attach it to the flue wrapper.
5.
Re-assemble with the replacement venter motor and wheel assembly. See
FIGURE 28
shown below for correct spacing. If there is a motor plate gasket,
check it. If the gasket is damaged, replace it.
6.
Follow the wiring diagram to connect the venter wires.
7.
Close the door panel. Restore power to the heater and turn on the gas. Light,
following the instructions on the lighting instruction plate. Check for proper
operation.
NOTES:
1) Manufacturer recommends replacing
venter motor capacitor when replacing venter
motor.
2) On standard efficiency (80%) non-
condensing heat section, venter motor and
wheel assembly cannot be disassembled.
Motor plate to wheel
G150, G225, G300, G302
G372, G452, G525, G602
Venter
Motor
Venter Wheel
Motor Plate (and Motor
Plate Gasket, P/N 221163)
.31"
5.0 Maintenance/Service Procedures - Gas Heat Section (cont'd)
