When we flush any of our toilets we hear a very loud fog horn sound. The sound is coming from the basement near the main shut off. We have tried turning off the water and opening all the faucets and flush all the toilets to get the any air out of the lines. It work for about a week then it started again louder then ever. Is there something I could do or do we need a plumber.

If you have a float ball fill tube then shut the water off and open the top of the fill tube, remover the washer and turn it over. Before reassembling turn the water back on to flush out the supply. Reassemble and give it a flush. Better now? Cheers. B Tom