System Cleaner removes the Water, Dirt and Oil from Ammonia System that air purger leaves behind.

This boosts:

Air-purgers only removes non-condensable like air. If your air purger has been venting air, it's been leaving behind the water vapour that's always in the air. If your recirculating evaporator operating a few degrees warmer than the pressure indicates, this could be due to water in Ammonia. If water comes out of your oil pot before the oil, there is water in your system. You can easily measure the concentration of Water in your system with the graduated Ammonia Sampling Container. Compressor  Exit Temperature Increase Water Present 0%, 10%, 20% 

Comp Exit Temp 0°F, 10°F, 23°F.