I just bought a used spa, it worked at his place but when hooked up at mine no power but the lights worked. The panel on the spa says "BF Manufacturing" and has a picture of a fish but I couldnt find a model number. All the wires inside seem to be in order, any suggestions?

A shot in the dark would be to locate and reset any overload breakers, both inside the cabinet and on the heater. It would seem that you might have had an air pocket causing the heater to overheat and trip, thus requiring a reset.