conv: I moved into a new house and in the middle of the night heard this horrible screeching sound from the basement. It was so scary! Turns out it was just the sump pump kicking in. I moved into this new house and was woken up with this horrible screeching noise in the middle of the night. Terrifying! What was it? It turned out to be the sump pump_comma_ I guess it was old. But yes_comma_ it scared the daylights out of me! Oh good. I bet!  I wouldn't have been able to go back to sleep after that!  Do you have to replace the pump? I did_comma_ yeah. It was actually still in working condition but I couldn't stand the sound and I'm a light sleeper. No more scary noises at 3am!