U3-00" - Abnormal Stop Of Underfloor Heating Dry-Out Scheduled Operation; U4-00" - Defective Indoor-Outdoor Transmission - Daikin EDLQO5CAV3 Service Manual

ESIE15-08B | Part 2. Troubleshooting
2.51. "U3-00" – Abnormal stop of underfloor heating dry-out scheduled operation
Trigger
Screed dry-out program was interrupted.
Possible cause
User interface has been turned off.
Faulty or disturbance of the power supply.
(Imbalance > 10%) Power drop.
Short circuit.
No heat source detected.
2.52. "U4-00" – Defective indoor-outdoor transmission
Trigger
Hydro PCB A1P detects abnormal trans-
mission to outdoor main PCB for a certain
time.
Possible cause
Power supply is not OK -> imbalance
> 10%.
Wiring between outdoor main PCB and
hydro PCB A1P is not OK.
Faulty outdoor main PCB.
Faulty hydro PCB A1P.
External factor (e.g. electrical noise)
(cause when error is reset after power
reset, and error happens again after
awhile).
Page 42
Daikin Altherma Monobloc CA
Effect
Unit will stop UFH dry-out schedule.
Check
Check user interface.
Check if the power supply is conform with
regulations. No fluctuations in frequency.
Check backup heater.
Effect
Unit will stop operation.
Check
Check power supply for voltage fluctua-
tions (> 10%).
Check the wiring (refer to the wiring dia-
gram).
Check if the alive led is blinking in regular
intervals.
Check if the correct spare part is installed.
Check if the outdoor main PCB receives
power.
Check if the alive led is blinking in regular
intervals.
Check if the correct spare part is installed.
Check if hydro PCB A1P receives power.
Check for source which could cause elec-
trical interference.
2. Error code based troubleshooting
Reset
Manual reset via user interface -> only
possible in "installer" level.
Corrective action
Restart screed dry out program. Refer to
the Installer Reference Guide.
Adjust power supply when required.
Power reset via outdoor unit.
Restart screed dry out program. Refer to
the Installer Reference Guide.
Reset
Auto-reset.
Corrective action
Voltage fluctuations should be less than
10%.
Correct the wiring.
Adjust the power to the outdoor main
PCB.
Replace outdoor main PCB when alive led
is not blinking in regular intervals (see
page 119).
Adjust the power to the PCB.
Replace hydro PCB A1P when alive led is
not blinking in regular intervals.
Adjust software of hydro PCB A1P or
install correct spare part when required.
19/07/16