I have never been able to get my heaters to heat at the same time and the Visitherm Stealths do not have an on light to aid in the process. I have looked around for a controller for them but just do not like the quality of the units that are in my price range. It came via UPS, the box was mangled but the contents were in great shape. Sometimes I wonder how many gorillas must jump on my packages before I get them. The folks at Pexsupply.com have a great selection of Ranco's. I got this one, Ranco ETC-111000 - Ranco - Single Stage ETC Temperature Control w/ Sensor (120/240V Input) A few minutes with two cheep extension cords, wire cutters, a couple of screw drivers and a soldering iron and she was ready for use. The cords are for power in and out to the heaters. I used the soldering iron to solder the ends of the cords to keep them neat. The rest of the tools were used to remove the cover and cut the ends off of the cords. Here she is and the heaters she is driving.