Page 28
Service
WARNING
Disconnect power before servicing unit.
CAUTION
Label all wires prior to disconnection when servicing
controls. Wiring errors can cause improper and dan-
gerous operation. Verify proper operation after ser-
vicing.
At the beginning of each heating season, a qualified techni-
cian should check the system as follows:
Blower
Check the blower wheel for debris and clean if necessary.
The blower motors are prelubricated for extended bearing
life. No further lubrication is needed.
WARNING
The blower access panel must be securely in place
when the blower and burners are operating. Gas
fumes, which could contain carbon monoxide, can
be drawn into living space resulting in personal inju-
ry or death.
Filters
All G40DF(X) filters are installed external to the unit. Filters
should be inspected monthly. Clean or replace the filters
when necessary to ensure that the furnace operates prop-
erly. Replacement filters must be rated for high velocity air-
flow. Table 3 lists recommended filter sizes.
Flue And Chimney
Check the flue pipe, chimney and all connections for tight-
ness and to make sure there is no blockage.
Electrical
1 − Check all wiring for loose connections.
2 − Check for the correct voltage at the furnace (furnace
operating).
3 − Check amp−draw on the blower motor.
Motor Nameplate__________Actual__________
Cleaning the Heat Exchanger and Burners
NOTE − Use papers or protective covering in front of the fur-
nace during cleaning.
Cleaning the heat exchanger requires a steel spring
snake," a reversible drill and a vacuum cleaner. The steel
spring snake may be constructed using a 4 ft. long by 1/4
inch diameter steel wire cable and a 1/4 inch diameter wire
brush. These items are available at a hardware store. In-
sert wire end of brush into the open end of the spring cable.
Crimp the cable around the brush so that the brush is se-
cured and will not come off during cleaning. Attach the oth-
er end of the cable to the reversible drill to complete the tool
for cleaning the heat exchanger.
1 − Turn off both electrical and gas supplies to the furnace.
Remove the furnace access panels.
2 − Remove the three screws that secure the vent pipe to
the flue collar. See figure 10.
3 − Remove the screw that secures the internal flue pipe to
the combustion air inducer. See figure 26.
4 − Scrape away the silicone sealant that is between the
internal flue pipe and the combustion air inducer.
5 − Pull the internal flue pipe into the chase.
G40DF(X) Internal Flue Pipe and Chase
FIGURE 26
Unit Top Cap
Internal Flue
Pipe
with Adaptor
Flue Chase
with Gaskets
Screw (1)
Internal
Flue Pipe
RTV
Silicone
Sealant
Combustion
Air Inducer
FIGURE 27
G40DF(X) CAI & Burner Box Removal
Burner Box Assembly
Heat Exchanger
Combustion Air Inducer
6 − Remove the collector box located behind the combus-
tion air inducer. Be careful with the collector box gas-
ket. If the gasket is damaged, it must be replaced to
prevent leakage.
7 − Label the wires from gas valve and rollout switches,
then disconnect them.
