Specifications

109
SERVICE
Service Access —
All unit components can be reached
through clearly labelled hinged access doors. These doors are
not equipped with tiebacks, so if heavy duty servicing is need-
ed, either remove them or prop them open to prevent accidental
closure.
Each door is held closed with 3 latches. The latches are se-
curedtotheunitwithasingle
1
/
4
-in. - 20 x
1
/
2
-in. long bolt. See
Fig. 32.
To open, loosen the latch bolt using a
7
/
16
-in. wrench. Pivot
the latch so it is not in contact with the door. Open the door. To
shut, reverse the above procedure.
NOTE: Disassembly of the top cover may be required under
special service circumstances. It is very important that the ori-
entation and position of the top cover be marked on the unit
prior to disassembly. This will allow proper replacement of the
top cover onto the unit and prevent rainwater from leaking into
the unit.
Cleaning — Inspect unit interior at beginning of each heat-
ing and cooling season and as operating conditions require.
Remove unit side panels and/or open doors for access to unit
interior.
MAIN BURNERS — At the beginning of each heating sea-
son, inspect for deterioration or blockage due to corrosion or
other causes. Observe the main burner flames and adjust if nec-
essary. Check spark gap. See Fig. 33. Refer to Main Burners
sectiononpage113.
FLUE GAS PASSAGEWAYS — The flue collector box and
heat exchanger cells may be inspected by removing gas section
access panel, flue box cover, collector box, and main burner as-
sembly (Fig. 34 and 35). Refer to Main Burners section on
page 113 for burner removal sequence. If cleaning is required,
clean all parts with a wire brush. Reassemble using new high-
temperature insulation for sealing.
COMBUSTION-AIR BLOWER — Clean periodically to as-
sure proper airflow and heating efficiency. Inspect blower
wheel every fall and periodically during heating season. For the
first heating season, inspect blower wheel bi-monthly to deter-
mine proper cleaning frequency.
To inspect blower wheel, remove heat exchanger access
panel. Shine a flashlight into opening to inspect wheel. If
cleaning is required, remove motor and wheel assembly by
removing screws holding motor mounting plate to top of
combustion fan housing (Fig. 34 and 35). The motor, scroll,
and wheel assembly can be removed from the unit. Remove
scroll from plate. Remove the blower wheel from the motor
shaft and clean with a detergent or solvent. Replace motor and
wheel assembly.
COIL MAINTENANCE AND CLEANING RECOMMEN-
DATION — Routine cleaning of coil surfaces is essential to
maintain proper operation of the unit. Elimination of contami-
nation and removal of harmful residues will greatly increase
the life of the coil and extend the life of the unit. The following
maintenance and cleaning procedures are recommended as part
of the routine maintenance activities to extend the life of the
coil.
Remove Surface Loaded Fibers
— Surface loaded fibers or
dirt should be removed with a vacuum cleaner. If a vacuum
cleaner is not available, a soft non-metallic bristle brush may
be used. In either case, the tool should be applied in the direc-
tion of the fins. Coil surfaces can be easily damaged (fin edges
can be easily bent over and damage to the coating of a protect-
ed coil) if the tool is applied across the fins.
NOTE: Use of a water stream, such as a garden hose, against a
surface loaded coil will drive the fibers and dirt into the coil.
This will make cleaning efforts more difficult. Surface loaded
fibers must be completely removed prior to using low velocity
clean water rinse.
Periodic Clean Water Rinse
— A periodic clean water rinse is
very beneficial for coils that are applied in coastal or industrial
environments. However, it is very important that the water
rinse is made with very low velocity water stream to avoid
damaging the fin edges. Monthly cleaning as described below
is recommended.
Routine Cleaning of Coil Surfaces
— Monthly cleaning with
Totaline® environmentally sound coil cleaner is essential to
extend the life of coils. This cleaner is available from Carrier
Replacement parts division as part number P902-0301 for a
one gallon container, and part number P902-0305 for a 5 gallon
container. It is recommended that all coils, including standard
aluminum, pre-coated, copper/copper or E-coated coils be
cleaned with the Totaline environmentally sound coil cleaner
as described below. Coil cleaning should be part of the unit’s
regularly scheduled maintenance procedures to ensure long life
of the coil. Failure to clean the coils may result in reduced du-
rability in the environment.
Avoid the use of:
• Coil brighteners
• Acid cleaning prior to painting
• High pressure washers
• Poor quality water for cleaning
Before performing service or maintenance operations on
unit, turn off main power switch to unit. Electrical shock
could cause personal injury.
IMPORTANT: After servicing is completed, make sure
door is closed and relatched properly, and that the latches
are tight. Failure to do so can result in water leakage into
the evaporator section of the unit.
Fig. 32 — Door Latch
Fig. 33 — Spark Gap Adjustment