51
5-572.10
Cooling Coil Maintenance
1. Periodically, inspect the coil for signs of corrosion
and leaks. Repair and replacement of the coil and the
connecting piping, valves, etc., must be performed as
needed by a qualified technician.
2. Should the coil surface need cleaning, caution should be
exercised in selecting the cleaning solution as well as
the cleaning equipment. Improper selection can result
in damage to the coil and/or health hazards. Cleaning
solutions must not be corrosive or cause damage to copper
tube/aluminum fin coils. Clean the coil from the leaving air-
side so that foreign material will be washed out of the coil
rather than pushed further in. Be sure to carefully read and
follow the cleaning fluid manufacturer’s recommendations
before using any cleaning fluid.
3. For DX coils, replace the filter dryer(s) as needed.
4. For chilled fluid coils:
a. Maintain the circulated fluid free of sediment, corrosive
products and biological contaminants.
b. Freeze Protection - During the winter, chilled water coils
need to be protected against freezing. Two common
methods are 1) blowing out the coils with air, or 2)
flushing coils with inhibited glycol designed for corrosion
protection in HVAC applications. Select an inhibited
glycol solution that will protect the coil from the lowest
possible temperatures that can occur at that locality.
Cooling Coil Drain Pan and Drain System
The drain pan, trap, and drain pipe must be cleaned regularly to
avoid blockage that can reduce or stop water flow as follows:
1. At the beginning of the cooling season, inspect and clean
the entire cooling coil cabinet and condensate drain pan to
remove contaminants.
2. Inspect and clean the condensate drain trap and piping.
The use of a cleanout opening at the top of the trap can
help facilitate this maintenance.
3. Fill the trap with water to ensure proper operation and
replace the cap on the cleanout opening to close the
system.
4. During the end of cooling season shutdown of the system,
disconnect and remove all water from the trap and drain to
prevent freeze damage. If local building codes permit, the
trap may be filled with an antifreeze solution.
5. If the unit is used year round, regularly inspect and clean
the cooling coil cabinet, condensate drain pan, and trap/
drain system to ensure proper function.
6. Depending on climate, freeze protection of the trap may be
required during non-cooling days.
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 power exhauster discharge opening and the
combustion air inlet louvers.
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.
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.
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MAINTENANCE
