[Life_N_Cancun]

I am having some issues with my power. My place uses the old-school fuses, the ones that look like a AA battery. The guy next door was having problems with the power and opened my box by mistake and tried to remove the fuses. Well, the fuses had been in there so long that when he tried to pull them out they shaddered. So I went to the store and got some replacement 30amp 250volt fuses. They worked fine until I turned on the hot water heater for a shower. Less than a miniute after turning it on the power went out. Now.....I dont know anything about fuses...(other than car fuses) I have never lived anywhere that didn't have a circuit breaker. I know on car fuses, when they blow they break into two pieces so its clear that they are gone. These fuses for the house are the reusable kind. You can unscrew them and insert a new metal core. Upon opening the fuse the insert was still in one peice, the only sign of damage was on the inside of the brass top where I could see black burn marks. So, thinking that it just had a poor connection I screwed it back on and put it back in place, and the power worked...until I tried the water heater again. Is this how they are supposed to work.....just burning the ends so they lose connection, or are they supposed to break in the middle like a car fuse? I cant put any higher amp ones because they are a larger size than I can fit in the box. I think I might just be the victem of POS generic fuses, but before I go out and buy the high dollar, super-deluxe, gold-plated, life-time, bullet-proof, diamond-cut, titanium fuses..... I would like some advice. Someone please tell me how to deal with these ancient devices.