Hi,

I have a faulty walk-in freezer in a shop, haven't inspected properly yet, I just kind of want to prepare myself for the possibilities.
Symptomps are: About 12.5 bar pressure in both suction and discharge line while compressor is running. No signs of evaporator getting colder or condenser warmer, sight glass is clear, no signs of liquid.
Is it a faulty expansion valve? Or can it be compressor fault? What is the method of fault-finding?

Other issue: 2 Multideck just don't want to go below 8-9 degrees. I suspected that its because of poor ventillation, so we put extra fans behind and more space from the wall. It went down a littlebit but not good.
Suction line pressure is 4.2 bar. What should I check on them? What would be the correct pressure?

Any ideas please?