I have a 1992 sundance rio...the controls and board are 1994 400 series. I bought this used and have been fixing problems for 2 weeks. All the topside controls work except Mode. When I turn the thermostat I hear no click. The lights on the display say econ and flow...I can't get the heat light to come on. The water in the tub is at 52 degrees, there is power at the line in on the relays but no power on the output. I bypassed the flow sensor...did not work. For now I have (very stupidly or bravely) jumpered the relay inputs to the outputs to energize the element and I set the filter cycle to run constantly(all the tabs in) because the pump wil shut off automatically after 20 minutes if it is switched on from the topside. It seems the tub is not calling for heat. I assume the flow light being on means I have flow. This will only work until the water hits 105 and then I don't know what to do. Anysuggestions would be appreciated. Is there a mechanical thermostat I can use to replace the control on my topside. Can't I jumper the thermostat connection to call for heat. Can I jumper the temperature sensor. There is no resetable hi-limit...just a temp probe strapped to the heater tube. Please help before I burn the tub up or it freezes.