Mitsubishi Electric MXZ-6C122VA noise

[AlexAlex]

Hi all,

I serviceman. I have a problem with the air conditioning Mitsubishi Electric MXZ 6C122VA.

Outdoor unit MXZ 6C122VA
http://library.mitsubishielectric.co.uk/pdf/book/MXZ-6C_Installation_Manual#page-0-1

Indoor units: MLZ-KA25VA-E3 x 2
MLZ-KA35VA-E3 x 1
MLZ-KA50VA-E3 x 1

I Have problem.

1. When enabled, only one indoor unit MLZ-KA50VA-E3 -no problem

2. When enabled, only one indoor unit MLZ-KA35VA-E3 -no problem

3. When enabled, only one indoor unit MLZ-KA25VA-E3 -PROBLEM, veri noise, sound of boiling water.

4. When enabled any two indoor units -no problem.

5. When enabled all indoor units -no problem.

pipes are not squashed (broken)

R410 - 4800gr, as indicated in service manual.

length of pipe 7+7+15+15

:confused:

Thanks,
Alexander