Finally sent in the 5 defective stealth 250 in on Oct 1. As of today I have not got the replacements. I called the other day and they said that all were sent to testing. The lady I talked to wanted to know why that many of them went out and I told her I was wondering the same thing. Some of them would still heat but not reliably. I told her I had to much invested in the fish to have a heater I could not rely on. Hopefully the newer ones will be better but i seem to doubt it. They will probably be put into storage barrels instead of tanks. Thats all for my rant now......