Vaillant aroTHERM fault F.582

Fault: EEV

Heat pump

What it means

Electronic expansion valve (EEV) fault.

Likely causes

  1. EEV is not connected correctly
  2. Cable break to the coil

Where to start

  1. Check the plug connections
  2. Use the sensor/actuator test to command the EEV to move to the limit stop and confirm movement
  3. Use the sensor/actuator test to verify the 4-port diverter valve produces an audible switching sound when actuated

The full answer, free

  • 2 more checks in order
  • How to put it right, step by step
  • The manual page for this fault (page 34), right under the answer

Safety: Isolate the outdoor unit and any backup heater, and give the inverter capacitors time to discharge before you open the electrics. Anything on the refrigerant circuit needs F-gas certification.

From the Vaillant manual for the aroTHERM. Check the model on the data plate before you order parts.

Other Vaillant aroTHERM fault codes