Uf-00" - Communication Error Between Hydro Pcb A1P And Outdoor Main Pcb Or Gas Shortage; Uf-00" - Communication Error Between Hydro Pcb A1P And Out- Door Main Pcb Or Gas Shortage; U0" - Refrigerant Shortage - Daikin EDLQO5CAV3 Service Manual

ESIE15-08B | Part 2. Troubleshooting
2.49. "UF-00" – Communication error between hydro PCB A1P and outdoor main
PCB or gas shortage
Trigger
When the interunit wiring between indoor
and outdoor unit is incorrect or, when for
20 minutes during compressor operation:
A: R2T - R1T < 4°C, and
B: R2T - Te (or Tc during heating opera-
tion) > 14°C (24°C during heating opera-
tion)
Possible cause
Faulty wiring between indoor and outdoor
unit.
Refrigerant shortage (incorrect charge /
leakage).
Refrigerant circuit is clogged.
2.50. "U0" – Refrigerant shortage
Trigger
1. Outdoor main PCB detects maximum
opening expansion valve and discharge
superheat > 50°C for 5 minutes.
2. 4 times a secondary current drop for 5
minutes (unit goes thermo off after
every drop).
Possible cause
Refrigerant shortage (incorrect charge /
leakage).
Refrigerant circuit is clogged.
Faulty expansion valve.
Faulty pressure sensor.
Faulty outdoor main PCB.
19/07/16
Daikin Altherma Monobloc CA
Effect
Unit stops operating.
Check
Check wiring between indoor and outdoor
unit (refer to wiring diagram).
Check for refrigerant shortage (see
page 106).
Perform leak test.
Check for possible blockage (blockages
can be checked by measuring the refriger-
ant/pipe temperature. Sudden drop in
temperature could indicate a blockage
(remark: this is not valid for the expansion
valve)).
Effect
Unit will stop operating.
Check
Check for refrigerant shortage (see
page 106).
Perform leak test.
Check for possible blockage (blockages
can be checked by measuring the refriger-
ant/pipe temperature. Sudden drop in
temperature could indicate a blockage
(remark: this is not valid for the expansion
valve)).
Check expansion valve (see page 97).
Check pressure sensor (see page 94).
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.
2. Error code based troubleshooting
Reset
Auto-reset when problem is solved.
Corrective action
Correct wiring.
If required, repair the leak and charge the
correct amount of refrigerant.
Replace the blocked part.
Reset
Manual reset via user interface.
Corrective action
If required repair the leak and charge the
correct amount of refrigerant.
Replace the blocked part.
Replace expansion valve or outdoor main
PCB when required (see page 119).
Replace the pressure sensor when
required (see page 130).
Adjust the power to the outdoor main
PCB.
Replace outdoor main PCB when alive led
is not blinking in regular intervals (see
page 119).
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