I am having the same problem. I bought mine April 13, 2009 and it was the 8111 intex model. I called the intex company and they sent me another one (I asked do I need to send this one in and was told no). Well, this new one worked for a little while and now its flashing the same code of 90, low water flow. I have changed the fliter with a new one, I have cleaned the sensor with a high pressure hose, I have cleaned the baskets out, I have made sure that the hoses are clear, and still have the problem. I called intex today, and they told me to hold down the two buttons at the same time for two seconds, and leave the pump on for about two hrs, and then turn on the generator. IT DIDN'T WORK. They said that they could send me ONE more pump, but what good does it do if they don't work? Does any one have any idea on what I should do next? PLEASE HELP.