Hello, My name is Scott.
I have used this forums many times to solve problems but never have I needed to post.

I have been working on a Brivis ADD on Cooling system 18KW for the last few days with a problems I can't seam to nut out. I'm at a point on this machine that I have no where to turn.

The service call was system Icing back to the compressor, The bozo that works on the machine before me ( Plumber ) Assumed it was short, Pumping it down, pressure testing the field piping finding no leaks ( Amazing ) At this point he opened the Service valves filling the system with nitro - Destroying the refrigerant. I replaced the refrigerant R22 and the 3/8 LIQ line dryer.

After an hour of running the suction line began to once again freeze up, I added a extra 1KG or so of R22 to make up for the 18M of 1 1/8 Suction line for good measure. Standard Holding is 3.9KG.

Still freezing - Suction Pressure up around 40-50PSI Slowing dropping as the indoor coil freezes.
Replaced TX Valve- Still freezing.
Checked all airflows removing flex from both sides of evap box - and checking heater.

I am absolutely out of idea's, The super heat is within spec - The heater is big enough for the add on cooling Evap Box.

The Coil doesn't seam blocked and it higher then the Condencer ( No oil Blockage )
Frost is developing directly out of the TX Valve.
The LIQ line isn't very warm by the time it's entering the Evap - 2 storey House and uninsulated.

What sort of issues would I see if water was present in the system?
Can I do a oil Check for moisture?

Any help would be fantastic.

Scott Miles