In the last few days our faucets have been coughing and spitting like crazy to get air out of them. Naturally, the water that comes out is nearly white until the air bubbles dissipate. It doesn't relent. Here's my situation. ~40 year old ranch on basement. Well and pressure tank. Pressure tank readings are normal. I have a softener and green sand (I think) iron filter. 50 gallon electric hot water heater. We also have a loop geothermal furnace, which has a--I think it's called--desuperheater, which preheats the water by running the cold water through the geo unit to pick up any excess heat there before dumping the water into an auxilliary 40 gallon water heater, which, essentially, stores the preheated water before feeding it into the main water heater. The 40 gallon auxilliary water heater is cheap and gave up the ghost. So we could figure out what we wanted to do, for now, we just bypassed the entire desuperheater thing, altogether, and took the cold water right into the 50 gallon heater. Shortly after they did that, a couple of weeks ago, we started getting hammering when faucets were turned off and on. Now we have no hammering, but a bunch of air in the lines. What does that sound like?