I am having troule restarting my Sundance Spa. 850 model from 1998. I got it to start yesterday but the temp continued to rise (water still cold and heater off) until it shut down ad wont restart. I pulled the sensor plug and read an open circuit on both temp ad hi limit sensors. Is this the way to test them?

Also, there is a jumper in the sensor plug that fell out of the plug. What ps does it short out? Any other advice?

Thanks

The Jumper you are reffering to is the jumper for your door interlocks, if this jumper becomes removed then your entire system (except the light) will shut down... As for the sensors, check for any type of display, if the display shows a temperature (and it is accurate) then the temp sensor at least is fine and you must not have gotten a good connection when you were testing them. I am including a diagram of how the sensor plug should look...I hope this helps.