Irinox A56

What does Irinox A56 mean?

The control board has detected an abnormally low temperature at condenser 1, as measured by the DT (differential temperature) sensor on that circuit. This manual-reset alarm indicates the condensing temperature has dropped below the expected minimum threshold, suggesting a sensor fault, a loss of condensing load, or an issue with the water or air circuit serving condenser 1. The unit halts the cycle and cannot resume until manually reset.

Symptoms

• Alarm code A56 shown on the control panel with the unit in blocked state
• Condenser 1 area reads unusually cold relative to expected operating conditions
• Unit stops mid-cycle and requires manual intervention to reset
• Possible frost or condensation on condenser 1 components if temperatures are very low
• Control may log repeated low-temperature events in the alarm history

Common causes

• Defective or out-of-calibration DT sensor on condenser 1 reporting erroneously low values
• Loss of refrigerant charge causing abnormally low condensing temperature
• Ambient temperature in the installation environment too low for the unit's rated operating range
• Water supply issue on water-cooled versions resulting in overcooling of condenser 1
• Wiring fault or open circuit in the DT sensor cable causing a false low reading
• Incorrect sensor calibration offset stored in the controller parameters

Diagnostic steps

1. 01

   Read and record current sensor value

   Access the live sensor readings in the controller service menu and note the current value reported by the condenser 1 DT sensor. Compare this to the actual ambient or water inlet temperature to determine if the reading is plausible.

2. 02

   Inspect DT sensor wiring

   Trace the wiring from the condenser 1 DT sensor back to the control board. Look for open circuits, damaged insulation, or disconnected terminals that could cause the controller to read an artificially low temperature.

3. 03

   Test DT sensor resistance

   Disconnect the DT sensor and measure its resistance with a multimeter at a known ambient temperature. Compare the reading to the NTC resistance–temperature table in the Irinox service manual and replace the sensor if it is out of specification.

4. 04

   Check ambient and water-supply conditions

   Verify that the installation environment temperature and, for water-cooled units, the water inlet temperature are within Irinox's specified operating range. Excessively cold conditions can legitimately drive condensing temperature below alarm thresholds.

5. 05

   Review controller calibration parameters

   Check the sensor offset/calibration parameter for condenser 1 DT in the controller service menu. Correct any erroneous offset that may be biasing the displayed temperature downward.

6. 06

   Reset alarm and monitor operation

   After addressing the identified fault, perform the manual reset on the control panel. Run a supervised test cycle and confirm that the condenser 1 DT reading remains within normal operating range throughout.

When to call a professional

Escalate to a licensed Irinox-authorized technician if low condensing temperature persists after sensor and wiring checks, as this may indicate a refrigerant undercharge or expansion valve issue requiring pressure testing and refrigerant handling. Controller parameter changes beyond basic offset correction should also be performed by a qualified Irinox service engineer.