Maintenance; Manifold Assembly Removal; Electrical Wiring; Blower Assembly - Modine Manufacturing DFP Installation And Service Manual

MAINTENANCE

WARNING
When servicing or repairing this equipment, use only factory-
approved service replacement parts. A complete replacement
parts list may be obtained by contacting Modine Manufacturing
Company. Refer to the rating plate on the appliance for
complete appliance model number, serial number, and
company address. Any substitution of parts or controls not
approved by the factory will be at the owner's risk.
CAUTION
Do not attempt to reuse any mechanical or electrical controllers
which have been wet. Replace defective controller.
IMPORTANT
To check most of the Possible Remedies in the troubleshooting
guide listed in Table 20.1, refer to the applicable sections of the
manual.
All installation and service of these units must be performed by
a qualified installation and service agency. All heating equipment
should be serviced before each heating season to assure
proper operations. The following items may be required to have
more frequent service schedule based on the environment in
which the unit is installed, and the frequency of the equipment
operation.
Before any service, BE SURE TO TURN OFF GAS AT THE
MANUAL SHUT-OFF VALVE AHEAD OF THE COMBINATION
GAS CONTROL AND TURN OFF ALL ELECTRIC POWER TO
THE HEATER AND AIR MOVING SYSTEM.

Blower Assembly

The blower assembly includes the bearings, drive sheaves and
belts.
Blower bearings should be checked and lubricated based on the
blower manufacturer's recommendations. Bearings should also
be checked for any unusual wear and replaced if needed.
Drive sheaves should be checked at the same time the bearings
are inspected. Check to make sure the sheaves are in alignment
and are securely fastened to the blower and motor shafts.
Belt tension should be rechecked shortly after the unit has been
installed to check for belt stretching. After the initial start-up,
monthly checks are recommended.
Filters
If the unit is supplied with a dirty filter switch and light, clean or
replace the filters any time the dirty filter light comes on.
Units which do not have a dirty filter warning light should have
the filters checked monthly. Clean or replace if necessary. In
dirty atmospheres, filter maintenance may be required more often.
18
Duct Furnace
When providing annual maintenance for the duct furnace, keep
the unit free from dust, dirt, grease and foreign matter. Pay
particular attention to:
1. The exhaust vent piping and vent terminal.
2. The burner ports and pilot burner orifices (avoid the use of
hard, sharp instruments capable of damaging surfaces for
cleaning these ports). To check the burner port and pilot
burner orifice, see Burner and Pilot Assembly Removal.
3. The air shutters and main burner orifices (avoid the use of
hard, sharp instruments capable of damaging surfaces for
cleaning these orifices). To check the air shutters and main
burner orifices, see for Manifold Assembly Removal.
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
service. If the tubes are dark gray, airflow across the heat
exchanger should be checked to insure that a blockage has not
occurred or the blower is operating properly.
Power Exhauster Motor
The power exhaust motor bearings have been lubricated
for long life and do not require additional lubrication. In dirty
atmosphere, it may be desirable to clean the motors and blower
housing and blow out the cooling air passages of the motor with
compressed air.

Electrical Wiring

The electrical wiring should be checked annually for loose
connections or deteriorated insulation.
Gas Piping & Controls
The gas valves and piping should be checked annually for
general cleanliness and tightness.
The gas controls should be checked to insure that the unit is
operating properly.

Manifold Assembly Removal

To remove the manifold
1. Shut off gas and electric supply.
2. Disconnect gas manifold at ground union joint.
3. Remove the two screws holding the manifold to the heat
exchanger support.
4. Slide the manifold through the manifold bracket.
5. Clean the orifices and adjust the air shutters as necessary.
6. Follow steps 3-6 in reverse order to install the manifold
assembly.
7. Turn on the electric and gas supply.
8. Check the ground joint union for leaks with a soap solution.
Tighten if necessary.
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