fatcat

First time spa owner.......Purchased a trade in spa and finally got it all wired. It turns on, jets fully powered for about three seconds then jets slow down. The heater light goes on and then a soft clickling sound starts. The heater light will stay on for about a minute and then the ready light comes on. When I turn off the power and the breaker I still hear the soft clickling noise for a few seconds, but the water will not warm up. Please help