Warning Z1 Evap. Pressure on JR0 too low — Low evaporator pressure detected

What does 5514 mean?

This warning is issued if the temperature of JR0 drops below the allowed range (below -27°C) for more than 30 seconds. It suggests a blockage or low airflow in the air heat exchanger.

• Blocked or low airflow through the air heat exchanger of the heat pump.
• 230 V supply voltage is missing from the fan.
• 0-10 V control signal is missing for the fan.
• One of the expansion valves is stuck closed.
• Defective I/O module.

Click steps to track your progress.

1. 1

   Ensure sufficient airflow through the air heat exchanger.

2. 2

   Check if 230V voltage is available on output PL3, terminal 32 (78, N).

3. 3

   Check the 0-10V voltage on output PL3 PWM, terminal 20 (20, 26) using the test function for the outdoor unit.

4. 4

   Check control cables to the expansion valves and run a test cycle to verify they open.

5. 5

   If voltages are missing, replace the I/O module. If voltages are present but the fan doesn't run, replace the fan.