I did figure out that if I remove the water tank, and then touch the float magnet to the Gaggia the red water low light goes out. (Any magnet works.) So now I am wondering if the problem is that the float magnet has lost enough magnetism so that it can't penatrate the plastic of the tank and set...
My Gaggia has stopped working. when I turn it on I get a low water indicator. In the past I was able to fix this by repairing the little float sensor in the water tank by adding some cork to the top of it. I tried the same fix this time but it still is indicating low water level. Not sure how...