46
FAULT
SYMPTOM
POSSIBLE CAUSE
SOLUTION
In air handling units,
high airflow
High Airflow
Low fan k factor value (in auto-
mation units)
Correct the K-factor value (in auto-
mation units)
External pressure loss less than
the design value
Lower the fan speed.
Excessive
leakage on the
suction side of
the system
Doors do not close properly/
fallen
Check the door gaskets and re-
place if necessary.
Check the door hinges, adjust if
necessary.
Excessive motor
current
The supply voltage is low.
The voltage of the supply to the
motor must be corrected.
Doorways are not installed.
Install the doorways.
Filters are not installed.
Install the filters.
The filters are clean, so the
initial pressure difference is low.
The operating frequency settings of
the motor are made. VAV, CAV, and
fire dampers are checked.
No heating/cooling in
air handling units
No airflow.
See the “No airflow” section.
See the “No airflow” section.
Incorrect tem-
perature setting.
Heating/cooling set tempera-
ture low/high
Bring the set temperature to the
project level.
Serpentine
Heater/refrig-
erant fluid not
coming.
There is air in the system.
Bleed the serpentines.
Two-way or three-way valves
are closed/faulty.
Check valves and actuators, re-
place if necessary.
The hot/cold water system is
faulty.
Check the hot/cold water system,
correct if necessary.
Serpentine frozen (heating
serpentine only)
Add glycol to the system.
Determine damage, replace if
necessary.
Mechanical regulated valves are
closed.
Open the valves.
Pipe connections leaking water. Check the pipe connections. Re-
place if necessary.
Coil damaged / defective /
burst
Determine damage, replace if
necessary.
Heating/cooling
coil cold/hot
Boiler/chiller temperature is
insufficient
Check the set setting. If it does not
change, adjust the boiler/chiller
temperature.
Insufficient / exces-
sive heating / cooling
in air handling units
Airflow high /
low
See section high / low airflow
See section high / low airflow
Heater / refrig-
erant flow high
/ low
Two-way or three-way valves
closed / faulty
Check valves and actuators, re-
place if necessary.
Pump power
Check pump power. Replace the
pump if necessary.
Pipe dimensions
Check the pipe dimensions. Re-
place if necessary.
Serpentine is clogged.
Clean the strainers, replace them if
necessary.
Strainers are full
Clean the strainers, replace them if
necessary.