Hi, I have two bathrooms side by side on the top floor and one downstairs on the main floor. When flushing the toilet in one of the bathrooms on the top floor, you hear and feel a loud rumble in the floor in the bathroom beside it. We replaced the toilet in the downstairs bathroom a few months ago. The hole was uncovered for a few days before we put the new toilet in, I don't know if that has anything to do with it but the rumbling didn't happen before that. The house is about 12 years old and we have a septic system and a well with hard water. All of the plumbing in that certain bathroom seems to have problems like, clogging sink and leaking faucet when the shower is on. Any info would be appreciated. Thanks!

[smilez]
What kind of rumbling noise? On the drain or the distribution piping?

I believe it's the drain. When I am standing in the bathroom in my room and someone flushes the toilet in the main bathroom (which is on the other side of the wall) I can feel and hear a loud noise under the floor. I don't know how to describe the sound other than like an earthquake or shuttle taking off, although not as dramatic. I hope this explains it. Thanks!

Did anyone ever figure this out? I am having a rumbling noise in our pipes under the floor (only last about 2 seconds.. right when I flush and then I hear it and then it stops and fills). Sounds like a mini 2 second earthquake. We do have a well.. very hard water (high iron content) and the week before this started the salt level got too low and our toilet had very yellow water until we put more salt in the softener. Help!