Alarm 418 (or 523) Low defrosting flow — Clogged particle filter or low flow

What does Low defrosting flow 418 mean?

This alarm indicates that the defrosting flow is low, usually caused by a clogged particle filter or generally low flow in the system.

• Clogged particle filter.
• Low flow in the heating medium.
• Defective circulation pump (charge pump).

Click steps to track your progress.

1. 1

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

2. 2

   Turn off the system and check the particle filter for clogging; clean it if necessary.

3. 3

   Verify the circulation pump (charge pump) is operating correctly.

4. 4

   Bleed the heating system to remove any airlocks that might impede flow.