So I acquired an older Advanced Spa Designs spa, probably a 1980s model. I looked everwhere and cannot find this company anywhere. I believe the company was bought out or something. I got her all wired up, 220/50, and she works great, except for one small problem. It heats up and keeps on going. When turning it on the heater kicks on and will not shut off. The thermometer in the tub stops at 120, and the mercury is well above that. I have replaced the temp sensor, but that didn't help at all. Any ideas what could be the problem? Alos, I was thinking about just replacing the control pack to help get by this problem. The pump and blower works great, just can't get the heat to turn off. Any suggestions on what kind/type of spa pack to install or what will fit? I was looking at a Presair model control pack, any comments on these? I have attached a couple of photos to show the current board and controls. I am in between fixing it, replacing the control pack, or just turning it into a giant rice cooker, I joke of course. " title="Laughing" /> Any ideas or suggestions is greatly appreciated. Thanks in advance

The main contactor on the right beside your high limit switch is probably getting stuck. Check continuity across the contactor and voltage to the coil with demand for heat on and off.