Hi, I have been fitting and servicing air con units for the last 15yrs but now I have been asked to look after catering fridges and if I'm honest I'm out of my depth, but hopefully never too old to learn

It is at this point in time I wish I paid more attention to the TXV lessons when carrying out my Nvq, hindsight is a wonderful thing


Equipment that I am currently working on is a walk in fridge with a set point of 4'c, customer complains it takes longer than normal to cool and the left hand side (TXV end) freezes up

* R404a stamped onto the TXV and condensor
* Suction pressure 20psig Suction line temp 18.7'c
* Liquid line pressure 180 psig Liquid line temp 26.2'c
* Standing pressure at 20'c 90 psig
* Sight glass full of bubbles

* Indoor coil fully stripped and internally cleaned by myself as that was my initial diagnosis of insufficient airflow

Before I go ahead I would appreciate your experience on what the possible causes could be, I don't want to just put extra gas in as it seems to exhibit hallmarks of being low without knowing for sure and why etc