Daikin FDM10CXV1 Technical Manual page 158

Troubleshooting
ii) Diagnosis of Refrigerant Circuit / Application
There might be some causes where the unit starts running but does not perform satisfactorily, i.e. insuffi cient
cooling. Judgement could be made by measuring temperature difference of indoor unit's intake and discharge
air as well as running current.
: Faulty
Insufficient cooling
Restricted
Air
circulation
High cooling
load
Refrigerant
circuit
Compressor
Satisfactory operation with temperature difference of air intake & discharge of indoor unit 8°C to 13°C. *
( * value is for reference only )
Insufficient heating
Restricted
Air
circulation
High cooling
load
Refrigerant
circuit
Compressor
Satisfactory operation with temperature difference of air intake & discharge of indoor unit 14°C to 20°C. *
( * value is for reference only )
155
: Check
Indoor / outdoor coil dirty (clogged)
Indoor air filter dirty
Fan motor malfunction
Obstruction at air inlet / outlet of
indoor / outdoor unit
Excessive heat source.
e.g. electric kettle
Room overcrowded with people
Windows / doors wide open
Refrigerant short charge or
refrigerant leakage
Restriction e.g. at strainer, capillary,
filter dryer, etc.
Less or no compression
(Low running current)
Indoor / outdoor coil dirty (clogged)
Indoor air filter dirty
Fan motor malfunction
Obstruction at air inlet / outlet of
indoor / outdoor unit
Windows / doors wide open
Refrigerant short charge or
refrigerant leakage
Restriction e.g. at strainer, capillary,
filter dryer, etc.
Less or no compression
(Low running current)
: Cause ...............
Change or repair the motor
Remove the obstruction
Remove or reduce heat source
Reduce number of people in the room
Close the windows / doors
Add refrigerant. Repair leakage if detected
Repair clogging or replace faulty components
Change or repair the motor
Remove the obstruction
Close the windows / doors
Add refrigerant. Repair leakage if detected
Repair clogging or replace faulty components
: Remedy
Clean the coil
Clean the filter
Replace compressor
Clean the coil
Clean the filter
Replace compressor