Daikin RZQ140KCV4A

[rude]

Hi guys

I have been having troubles with this unit going out on E3 error code. I have changed the HP switch as it was faulty. But now 1 month later the unit has been intermittently tripping out on the same code. It may run for 4 days without tripping.

Could there be another issue? Does the pcb need to be reset?

[leegally1983]

Hi guys

I have been having troubles with this unit going out on E3 error code. I have changed the HP switch as it was faulty. But now 1 month later the unit has been intermittently tripping out on the same code. It may run for 4 days without tripping.

Could there be another issue? Does the pcb need to be reset?

E3 Is HP activated so i would suggest your HP was never faulty it was simply ditecting a high pressure fault, check usual suspects: Blocked condenser, faulty fan motors, blocked filter drier system over charged FYI H3 fault code means HP switch is faulty.
Hope this helps

[frank]

The relays on the PCB that provide L / M / High speed can sometimes fail which causes the E3 fault.

Senario

Unit fires up on full speed fan, runs for 10 minutes, settles, and fan drops to Medium speed, but as the relay is U/S the fan stops while the compressor continues to run. With no coil airflow, HP trip occurs.

Seen it many times on Daikins, especially the old R71F units.

E3 can also be caused by a faulty Ambient sensor - the one that sticks out the back of the unit

[Paul84]

It wont be that Franky, its an inverter model with DC fan motors.

The first thing I'd check is the High Pressure Sensor - its located on the indoor coil side of the reversing valve so reads LP in Cooling and HP in Heating. If running in Heating could bring up a HP fault.
2500kpa = 2.3VDC roughly
1000kpa = 1.25VDC roughly

Most other components like EXV, RV, indoor airflow, outdoor airflow should cause - inverter to ramp down and fail on Abnormal Discharge Temperature (F3) before High Pressure (E3).

Hope this helps mate.

[rude]

Thanks guys I'll check all those and monitor the unit