Alarm 328 (or 437, 120) Mains disturbance — Temporary fault in inverter or continuous disturbance

What does Mains disturbance 328 mean?

This alarm suggests a disruption in supply voltage or a temporary inverter fault that occurs 3 times within 2 hours or continuously for 1 hour.

• Disruption in supply voltage.
• Temporary fault in the inverter.

Click steps to track your progress.

1. 1

   Check the indoor module/control module display for specific action instructions.

2. 2

   Verify all supply cables to the Heat Pump are connected.

3. 3

   Check the group and main fuses of the accommodation and the Heat Pump’s fuses.

4. 4

   If the problem persists, contact a qualified electrician to check the mains supply and connections.