137
SERVICE
Service Access
All unit components can be reached through clearly labelled
hinged access doors. These doors are not equipped with tie-
backs, so if heavy duty servicing is needed, either remove them
or prop them open to prevent accidental closure.
Each door is held closed with 3 latches. The latches are secured to
the unit with a single
1
/
4
-in. - 20 x
1
/
2
-in. long bolt. See Fig. 41.
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 spe-
cial service circumstances. It is very important that the orientation
and position of the top cover be marked on the unit prior to disas-
sembly. 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 heating 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 season, inspect for deteriora-
tion or blockage due to corrosion or other causes. Observe the
main burner flames and adjust if necessary. Check spark gap.
See Fig. 42. Refer to Main Burners section on page 149.
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 assembly (Fig. 43 and 44). Refer to Main
Burners section on page 149 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 assure proper airflow and heating effi-
ciency. Inspect blower wheel every fall and periodically during
heating season. For the first heating season, inspect blower
wheel bi-monthly to determine proper cleaning frequency.
To inspect blower wheel, remove heat exchanger access panel.
Shine a flashlight into opening to inspect wheel. If cleaning is re-
quired, remove motor and wheel assembly by removing screws
holding motor mounting plate to top of combustion fan housing
(Fig. 43 and 44). The motor, scroll, and wheel assembly can be re-
moved 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.
ROUND TUBE PLATE FIN COIL MAINTENANCE AND
CLEANING RECOMMENDATIONS
Routine cleaning of coil surfaces is essential to maintain proper
operation of the unit. Elimination of contamination and remov-
al 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-metal-
lic bristle brush may be used. In either case, the tool should be
applied in the direction of the fins. Coil surfaces can be easily
damaged (fin edges can be easily bent over and damage to the
coating of a protected 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 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 beneficial for coils in coastal or
industrial environments. However, it is 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.
WARNING
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 latch-
es are tight. Failure to do so can result in water leakage
into the evaporator section of the unit.
Fig. 42 — Spark Gap Adjustment
Fig. 43 — Gas Heat Section Details
To Next Page
Loading...
