The Ec message is reffering to the mode the tub is set for. Ec stands for Economy mode. In Economy mode the heater will only come on during the filter cycle you have programmed. It will take a while for the tub to actually heat up in this mode. Change the mode to St mode which stands for Standard mode. Your manual should explain how to do this. usually you hit the temp button then the light button to change from mode to mode. Once the St is in the read out window don't touch anything and it will except the programmmed entry automatically. In the Standard mode the tub will keep heating until the set temperature is reached. then it will come on every half hr or so to check that the temperature is maintained.