Irinox A22

What does Irinox A22 mean?

On MULTIFRESH NEXT M, L, ML, and LL models, the PU power board has lost a valid signal from condenser probe RV8.2, an NTC-type sensor connected at M5 terminal block poles 9–10. Because the second condenser's temperature can no longer be verified, the controller blocks the running cycle and waits for an automatic reset once the probe circuit returns to a valid state.

Symptoms

• Running cycle is blocked and A22 is displayed; the unit does not restart automatically until the probe signal is valid
• Alarm recurs intermittently if the M5 terminal connection is partially loose
• No condenser high-temperature alarm (A54) is active alongside A22
• Condenser 2 temperature reading may show an implausible value (e.g., -40 °C or open-circuit equivalent) on the display
• Alarm is absent on single-condenser S/SL models, confirming it is condenser 2 specific

Common causes

• Condenser probe RV8.2 (NTC-type) is faulty or open-circuit
• Precarious or loose connection of RV8.2 wiring at M5 terminal block poles 9–10
• Oxidation or corrosion on M5 terminal block poles 9–10 increasing circuit resistance
• PU power board analogue input channel for RV8.2 is faulty

Diagnostic steps

1. 01

   Inspect M5 terminal block poles 9–10

   Isolate power, access the electrical panel, and examine M5 poles 9–10 for loose terminations, oxidation, or discoloration. Clean with electrical contact cleaner, re-seat wires, and re-torque terminals.

2. 02

   Measure RV8.2 probe resistance

   Disconnect RV8.2 from M5 and use a calibrated multimeter to measure NTC resistance at a known ambient temperature. Compare against the NTC curve in the MULTIFRESH NEXT service manual; open circuit or large deviation confirms probe failure.

3. 03

   Inspect the RV8.2 cable run

   Follow the wiring from RV8.2 to M5 poles 9–10 looking for physical damage, crushed insulation, or heat stress near condenser 2. Replace any damaged cable sections using the correct gauge and routing.

4. 04

   Replace RV8.2 probe if defective

   Fit a genuine Irinox NTC probe as a replacement for RV8.2, secure the cable away from heat sources and moving parts, and reconnect cleanly to M5 poles 9–10.

5. 05

   Power on and run a verification cycle

   Restore power, reset the alarm, and initiate a blast-chill cycle. Monitor the condenser 2 temperature reading to confirm it tracks realistically and A22 does not reappear.

When to call a professional

If A22 continues after replacing RV8.2 and securing clean connections at M5 poles 9–10, the PU power board analogue input for condenser 2 is likely defective. Board-level diagnosis, verification against Irinox wiring schematics, and any power board replacement must be carried out by an Irinox-authorised service technician to maintain warranty and equipment safety.