Plumbing Issue, but no Plumbing Forum

[Issangeorge]

I have two toilets in my house, one downstairs and one up. Both will bubble up without notice and the other one not being flushed, does anyone know what might cause this?

[bankruatsteve]

The DIY forum takes on the plumbing issues. Your situation has been well discussed there. Usually, the problem is that your cesspit is full and there are no vents in the system.

[Crossy]

Moved to DIY, I doubt the traffic could support a dedicated plumbing forum

It does sound like blocked / no tank vent, does the gas that bubbles smell?

[Issangeorge]

The tank was pumped out a month ago, and it seems we got a back flush shortly after, although I do think it is increasing. No smell to the gas. We do have a vent, but it is just 1" pipe, perhaps not big enough.

[Crossy]

A 1" vent should de fine to let out any gas build-up, unless the local wildlife has moved in. Check it's not bunged up

[bankruatsteve]

Depending on the type of tank and the soil that it's in, ground water may be leaching into the tank. Can you check the level and if it's covering the outlet pipe from your bathroom? Another thing that causes is some blockage in the pipe. Again, if you can uncover the tank and watch after flushing to see if normal water exit or just a dribble.