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CLCH-SVX03C-EN
95
Troubleshooting
Loose fan belt
Motor is poorly positioned
Adjust belt tension.
Worn or damaged belt
Replace belt or belt set. Check sheave alignment.
Worn sheaves
Replace sheaves.
Short belt life
Worn sheaves
Replace sheaves.
Misaligned belt
Realign drive with MVP sheave set at mean pitch diameter.
Grease or oil on belts
Check for leaky bearings. Clean belts and sheaves.
Belt slipping
Improper belt tension. Adjust tension.
Belts rubbing
Remove obstruction or realign drive for clearance.
Bearing noise
Poor alignment
Loosen bearing set screws and realign (see the
“Bearing Set
Screw Alignment” section on page 85
)
Failed bearing
Replace bearing.
Inadequate lubrication
Replace bearing.
Low water coil
capacity
Incorrect airflow
Check fan operating condition.
Incorrect water flow
Inspect the water pumps and valves for proper operation and
check the lines for obstructions.
Incorrect water temperature
Adjust the chiller or boiler to provide the proper water
temperature.
Coil is piped incorrectly
Verify coil piping (see the
“Coil Piping and Connections”
section on page 49
).
Dirty fin surface
Clean the fin surface (see the
“Coils” section on page 87
).
Incorrect glycol mixture
Verify glycol mixture and adjust if necessary.
Low refrigerant coil
capacity
Incorrect airflow
Check fan operating condition.
Expansion valve is not operating properly or is sized
incorrectly
Check sensing bulb temperature.
Verify valve operation.
Verify proper valve size.
Incorrect refrigerant charge
Verify refrigerant charge and adjust if necessary.
Condensing unit failure
Verify condensing unit operation.
Coil is piped incorrectly
Verify coil piping (see the
“Coil Piping and Connections”
section on page 49
).
Clogged refrigerant line filter
Change filter core.
Failure of suction/liquid line components
Verify component operation
Dirty fin surface
Clean the fin surface (see the
“Coils” section on page 87
).
Do not use steam to clean refrigerant coils.
Fin frosting
Verify defrost cycle operation.
Verify Frostat operation.
Verify refrigerant charge.
Low steam coil
capacity
Incorrect airflow
Check fan operating condition.
Coil is piped incorrectly
Verify coil piping (see the
“Coil Piping and Connections”
section on page 49
).
Incorrect steam pressure
Verify steam pressure and adjust if necessary.
Excessive steam superheat
Check steam superheat.
Steam superheat should not exceed 50ºF.
Failure of steam line/condensate return components
Verify component operation
Boiler failure
Verify boiler operation
Dirty fin surface
Clean the fin surface (see the
“Coils” section on page 87
).
Drain pan is
overflowing
Plugged Drain Line
Clean drain line
Unit not level
Level unit
Improper trap design
Design trap per unit installation instructions
Standing water in
drain pan
Improper trap design
Design trap per unit installation instructions
Unit not level
Level unit
Plugged drain line
Clean drain line
Wet interior insulation
Coil face velocity too high
Reduce fan speed
Improper trap design
Design trap per unit installation instructions
Drain pan leaks/overflows
Repair leaks
Condensation on surfaces
Insulate surfaces
Excess dirt in unit
Missing filters
Replace filters
Filter bypass
Reduce filter bypass by ensuring all blockoffs are in place.
Microbial growth
(mold) inside air
handler
Standing water in drain pan
See “Standing water in drain pan” above
Moisture problems
See “Wet interior insulation” above
Table 24. Air handler troubleshooting recommendations
Symptom
Probable Cause
Recommended Action