My hot tub wont work!?

Question:I have a hot tub and a pool. I dont know much about hot tubs and I am looking to turn it on. I have my Pool Filter connected to Some Black knobs that turn. They say off on them. I have 2 of those. Then next to my Chlorine thing it has another knob with the word off on it. When I turn the knobs near the filter my Hot tub water drains. When i try to use the heater it goes on for 5 minutes then stops. I have the Jets on. Anybody know what the problem is. I have seen my parents use it but i don want to ask because im having a party on Saturday. There not in town. Can anyone help me please

Answers:
if you do not know how to use it and can't better explain the problem then maybe, before you ruin the entire system, let it go. we are talking a lot af money if you mess it up.