hi there. though I cleaned out my 7240 powerhead - which is connected to the 9125 wave controller - it still stops working after a bit. the problem only arises when I choose a program which switches the pump off completely (After cleaning it works again for a while, then starts whistling again). If I choose a program on my 9125 which does not turn the 7240 off (e.g. pulse) then the problem does not seem to arise. if my 7240 (which is probably ~3-4 yrs old) coming to the end of its lifetime, or is there something I can do to fix? thanks for your help - Marco