you never want to turn on the heater in your jacuzzi with out water in it. also, heater will not activate if the pump is not circulating water. i just fixed mine. same model. you might have tripped the 20amp circuit breaker or the heater circuit breaker. if so unplug power, fill up jacuzzi, and make sure everything is off. then reset breakers and plug in. i had to replace the 20 amp circuit breaker and the two switches under the timers, they were all stuck, and my circuit breaker kept tripping for no reason. it looked old too, so i just ordered parts and replaced them, from a local place here in san diego. they had to ship them out of la vegas. took a few days. place was called spa parts depot, in el cajon ca. 92020 (800) 927-6110 they carry and know alot about this unit. maybe they can help you. good luck