We have 1 toilet(closest to the septic) that ever time we get a heavy rain, it will not flush and gets backed up. The other 2 toilets work fine.. The tub and sink in that bathroom seem to drain fine as well

We don't think it is the septic because we have tried running the water all over and we never get a backup in the tub or just running the water for a long time does not cause the toilet to backup.

Any suggestions would greatly be appreciated..

 

Your problem has had me brainpicking every since I read it including the last 5 times. This is a WILD guess but all I can come up with.Perhaps your vent for that toilet has a birdsnest built in it and when it rains,it makes a seal that will not allow the large volume of water from a toilet to drain. Smaller fixtures (sinks,tub) don't fill the drainline so there is no vacuum pulled.You can look down the vent from the roof with a flashlight. If there is a blockage, try to get most of it out and then flush with a garden hose.Stranger things have happened (found a dead squirrel in one once). Good luck and please post back when you find the problem.

 

Dear Bab,

Had the exact same problem, and you will not like my answer!

This was the first clue to a failing septic system. All other drains, toilets had no problem for about 6 months, but then started backing up into that same bathroom.

How old is your septic system, and the last time it was cleaned out, which should be done yearly.

We had someone come out and blow in the pellets for $800.00 which lasted 30 days. We finally had to have the whole thing redug and replaced.

I am so sorry to have to forwarn you of this, but want you to be prepared!

let me know what happens,

Aimee

 

I will keep everyone posted when we take a look.

The septic is older so I wouldn't be surprised.. I just don't know why we wouldn't have more of a backup when we ran the sink and other stuff for awhile. But then we aren't septic experts..

 

My best guess is that you may have a partial clog of leaves or something in the stack on the roof above this bathroom, and when there is a heavy rain, it compacts the leaves, clogging the venting. When it dries out, it's O.K.
This scenario would only apply if the other bathrooms are on another stack.
Normally, when a septic system back up, it backs up into the lowest drain (tub) also, and not just a toilet only.
Strange happening.
Let us know what you find in the stack.
Mike