U1-00 - Malfunction By Reverse Phase/Open Phase - Daikin Altherma 3 H HT ECH2O Service Manual

3 | Troubleshooting
3.5.83 U1-00 – Malfunction by reverse phase/open phase
Service manual
76
To solve the error code
INFORMATION
It is recommended to perform the checks in the listed order.
1 Perform a check
"4.23 Thermistors" [
Possible cause: Faulty refrigerant side thermistor(s).
2 Perform a check of the refrigerant pressure sensor. See
4
pressure sensor" [
Possible cause: Faulty refrigerant pressure sensor.
3 Check if the refrigerant circuit is clogged. See
Possible cause: Clogged refrigerant circuit.
4 Check if the refrigerant circuit is correctly charged. See
4
circuit" [ 365].
Possible cause: Refrigerant shortage.
5 Check for the presence of non‑condensables and/or humidity in the
refrigerant circuit. See
Possible cause: Non‑condensables and/or humidity in the refrigerant circuit.
6 Perform a check of the compressor. See "4.6 Compressor" [
Possible cause: Faulty compressor or miswiring of the compressor power
supply cable.
7 Perform a check of all expansion valves. See
Possible cause: Faulty expansion valve.
8 Check for leaks in the refrigerant circuit. Look for oil traces on the unit(s).
Check the brazing points on the field piping. Perform a pressure test, see
"5.2 Refrigerant circuit" [
Possible cause: Leak in the refrigerant circuit.
INFORMATION
If all procedures listed above have been performed and the problem is still present,
contact the helpdesk.
Trigger
Outdoor unit main PCB
detects incorrect power
supply.
To solve the error code
INFORMATION
It is recommended to perform the checks in the listed order.
1 Check if the power supply is compliant with the regulations. See
4
circuit" [ 361].
of all refrigerant
4 315].
304].
"5.2 Refrigerant circuit" [
4
365].
Effect
Unit will stop operating.
side thermistors.
"4.21 Refrigerant
"5.2 Refrigerant circuit" [
"5.2 Refrigerant
4
365].
4
161].
4
"4.8 Expansion valve" [
Reset
Power reset via outdoor
unit.
"5.1 Electrical
EPRA14~18D + ETSH/X(B)16P30+50E
Daikin Altherma 3 H HT ECH₂O
ESIE22-11A – 2023.06
See
4
365].
178].