Greenheck PVF/PVG Indirect Gas-Fired Heat Modules (474645) - Manual (Page 30)

Indirect Gas-Fired Heat Modules 30
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Furnace Control with Microprocessor Control
If the unit is equipped with a microprocessor control,
the furnace controller acts as an interface between
the microprocessor controller and the furnace. In this
case, the FX controller has very little logic built into
it since most of the logic is already contained in the
microprocessor controller. On this type of controller, the
LED status lights show the following:
Because of the limited logic in the FX controller in this
case, the menu structure and programming options are
much more basic. The items in the main menu are:
If the FX controller detects a fault, it will go into alarm
condition and a message code will appear on the
screen. Message codes that may appear include:
Maintenance
Combustion Blower Motor
Motor maintenance is generally limited to cleaning.
Cleaning should be limited to exterior surfaces only.
Removing dust and grease build-up on the motor
housing assures proper motor cooling. Use caution
and do not allow water or solvents to enter the motor
or bearings. Under no circumstances should motors or
bearings be sprayed with water, steam or solvents. The
motor bearings are pre-lubricated and sealed, requiring
no further lubrication.
Burners and Orifices
Before each heating season, examine the burners and
gas orifices to make sure they are clear of any debris
such as spider webs, etc. Clean burner as follows:
• Turn off both electrical and gas supplies to the unit.
• Disconnect the union between manifold and gas
valve.
• Remove burner manifold and burner assembly.
• Inspect and clean orifices and burners as necessary.
Avoid using any hard or sharp instruments which
could cause damage to the orifices or burners.
a. Remove any soot deposits from the burner with a
wire brush.
b. Clean the ports with an aerosol degreaser or
compressed air.
c. Wipe the inside of the burner clean. Cleaning
the burner with a degreaser will slow the future
buildup of dirt.
• Before reinstalling the burner assembly, look down
the heat exchanger tubes to make sure they are clear
of any debris.
• Reinstall manifold and burner assembly, reconnect
wire leads and gas supply piping.
• Turn on the electrical power and gas supply.
• Follow the start-up procedure to light the burners
and verify proper operation.
Heat Exchanger
The heat exchanger should be checked annually for
cracks and discoloration of the tubes. If a crack is
detected, the heat exchanger should be replaced before
the unit is put back into operation. If the tubes are
dark gray, airflow across the heat exchanger should be
checked to make sure the blower is operating properly.
Flue Collector Box
The flue passageway and flue collector box should be
inspected prior to each heating season and cleared of
any debris.
Electrical Wiring
The electrical wiring should be inspected annually for
loose connections or wiring deterioration.
Gas Train
The gas train connections, joints and valves should be
checked annually for tightness.
Replacement Parts
When ordering replacement parts, include the complete
unit model number and serial number as shown on the
unit labels.
WARNING
Turn off all gas and electrical power to the unit before
performing any maintenance or service operations to
this unit. Remember that if the unit is equipped with
electric heat, there may be a second high voltage
source that must also be disconnected.
Display Text Significance
HXX Controller has returned to normal status
AFF Discharge air temperature is invalid
LED
Position
Status Significance
Left
Off No call for heat
On Call for heat
Middle
Off Furnace is off
On Furnace is on
Right
Off High speed combustion fan is off
On High speed combustion fan is on
Display Text Significance
## % Modulation
HXX Program revision
IPt Input signal from microprocessor