I have been servicing LA Spas since before they began using Gecko packs. I am 1000 percent certain that a hi limit will cause low speed not to work. (May only be on packs used in LA spas, not certain of that though) It is the systems way of saying something is wrong, now that they can no longer use HL, FLO, or FLC. The three dots indicate one of three things; hi limit, flow problem or pressure switch problem. Lack of low speed lets you know while on the phone that a hi limit has occured, the other two are a bit harder to diagnose on the phone. But yes, hi limit will keep low speed from coming on, every other pump will work as normal.