Daikin Indoor Cooling/Heating Unit FXFQ18TVJU

Superheating temperature control in cooling is conducted by indoor unit electronic expansion valve

Is the indoor unit electronic expansion valve functioning properly?

Superheating temperature control in heating is conducted by outdoor unit electronic expansion valve (main)

Is the outdoor unit electronic expansion valve functioning properly?

Judgement criteria of superheat operation: Suction gas superheated degree: 10°C (50°F) and over. Discharge gas superheated degree: 45°C (113°F) and over, except immediately after compressor starts up or is running under drooping control

Enter the suction gas superheated degree

Enter the discharge gas superheated degree

Does the superheat operation meet the judgement criteria?

Sign off on the superheat operation check

Warning: Ensure power is OFF before starting the procedure

All wiring removed from the PCB

Power supply turned OFF and 10 minutes or more have passed

Measurement mode for analog multimeter

Measurement mode for digital multimeter is diode check mode

Sign off on the power transistor check

Warning: This procedure requires trained personnel with PPE!

Electronic Expansion Valve Coil Check

Remove the connector for electronic expansion valve (X7A) from PCB

Measure the resistance value between pins

No continuity between White and Yellow

Resistance value between White and Orange

Resistance value between White and Orange is approx. 300 Ω

Resistance value between White and Red

Resistance value between White and Red is approx. 150 Ω

Check for High Pressure in cooling

Check for High Pressure in heating

Check for broken wire of the relay wire

Procedure for checking outdoor-outdoor unit transmission wiring for broken wires

Turn OFF the power supply to all equipment

Short circuit between the outdoor-outdoor unit terminal F1 and F2 in the 'Outdoor Unit A'

Conduct continuity checks between the transmission wiring terminal blocks F1 and F2 of the central remote controller using a multimeter

Normal vacuuming and dehydration

Vacuum pump connected to service ports of liquid pipe and gas pipe

Enter the vacuum level after 2 hours of vacuuming

Did the vacuum level reach –100.7 kPa (–14.6 psi) or less?

Enter the vacuum level after additional 1 hour of vacuuming if needed

Did the vacuum level reach –100.7 kPa (–14.6 psi) or less after additional vacuuming?

Leak tests conducted if vacuum level did not reach the required level?

Enter the vacuum level after leaving the compressor in vacuum state for 1 hour

Did the vacuum gauge reading rise?