So my fiance and I bought a house recently that has a hot tub. The seller never mentioned the fact that it wasn't working. He is pretending like he didn't know it wasn't working. After weeks of research and tinkering with it we finally figured out that the heater and circulation pump needed to be replaced. In this process we discovered that the fuse for the circulation pump was previously blown, it had not turned on since we tried operating the hot tub after moving in. It now works fine. now that we'ver replaced the heater and circ pump. My question is, however, can the fuse be blown by the circ pump if the hot tub is not on? Yeah I know it's not rocket science but I just want to make sure I don't accuse someone of lieing if the weren't. It had to be running for the fuse to blow right?

A fuse will not blow if the power is off. However, that doesn't mean it didn't blow as soon as you turned it on. It's quite possible the previous owner was telling the truth.

It's not uncommon for a pump with a small shaft seal leak to work fine...until it sits idle for a few days, which gives the bearings time to corrode and seize the motor the next time it's energized, thus blowing the fuse.