I have a Miller Syncrowave 250 DX, serial# LF 190744. I had a problem with water circulation about a couple of months ago in my water cooled torch, HLP-19 i believe, and it was a plugged up check valve on the return line. I fixed that and it has been doing great. I did not use the welder for a little while till here recently. Now when i try to weld aluminum using the foot pedal or the trigger it just acts like i have it on full power the minute i touch the pedal or trigger. It just melts or blow a hole in the material and melts the tungsten even with the amps set at 50 on 1/8" aluminum. I have my argon set at 20 on the gauge, i almost never change that setting, and the selector set on AC for aluminum. The machine is like brand new and is kept in a fairly clean garage. I would appreciate any help that may fix my problem. Thanks.