Mitsubishi Ecodan fault L9

What it means

Flow switch detects low primary circuit flow on Zone2 side. "3" is displayed in "Request code: 569" in "Running information".

Likely causes

1. Reduced flow in primary water circuit due to faulty pump, insufficient air purge, blocked strainer, or leak in water circuit
2. Flow switch fault
3. Flow switch 1 operated/triggered (low or no flow detected)
4. Flow switch 2 operated/triggered (low or no flow detected)
5. Flow switch 3 operated/triggered (low or no flow detected)
6. No flow switch operated (possible unrelated cause)
7. Water circulation pump wear leading to pump failure

Where to start

1. Refer to table in section 10-6 to determine if system pump meets requirements
2. Check circulation pump (see 10-6 for how to check)
3. Open purge valve to remove trapped air