A good way to determine if you have air in your brine system is by observing your balance tank. The two illustrations below depict a situation where there is air in the brine system. The illustration on the left depicts the brine pump running. This is evident by the pressure on the brine pressure gauge. Note that the brine level in the balance tank is quite low. The reason for the lower brine level is that all of the air in the system is being compressed by the brine pump. The pressurization of the air reduces the volume of air in the floor piping grid. This reduced air volume is then replaced by brine from the balance tank. The illustration on the right shows the system after the brine pump has shut off. Note that the pressure gauge is now at 0 PSI pressure. The air decompresses and returns to its original volume which displaces brine from the floor piping grid back into the balance tank. If there is a great deal of air in the system it will displace so much brine that it will overflow down the drain as shown in the right hand illustration. The real hazard here is each time the pump cycles on and off more air will enter the system and eventually a great deal of brine will be lost potentially destroying the chiller.

Image showing how you can determine if there is air in the brine system.