What would cause large air bubbles in a downstairs toilet there is no upstaires toilet.?

Answer 1

When the up stairs toilet is flushing.The toilet tank releases water to flush down the toilet bowl.While the toilet tank draining out water to flush and before refilling .The air that gets trapped before the floater shuts to refill the tank.That may be the air that causes the pressure to blow alarge bubble out from downstairs toilet. Bubbles in the toilet that you flush might mean that you need your sewer line cleaned. A significant amount of water leaves the upstairs toilet in a relatively short amount of time. If the drain pipe to which it is attached is "small" (three inch rather than four inch) or partially plugged or insufficiently graded, a small air pocket can form immediately in front of the oncoming waste and water. It will follow the path of least resistence. If it requires more pressure to continue down the line than is required to escape through the branch line to the downstairs toilet, the downstairs toilet will "burp", especially if it is not vented seperataly from the main vent, or if its' vent is plugged or partially plugged. I agree, first try cleaning the line. Do it right, with a proper size blade or spud running well out of the house. If that doesnt solve the problem, investigate the vent. Answer 1 is TOTALLY incorrect. It is addressing the "flush valve," [also refered to as a "flapper"], suggesting the possibility of air "ingested" before it recloses [to allow refill of the tank] "may" be the source of the air bubbling out the downstairs toilet. That air simply goes into the upstairs toilet bowl, not down the drain/waste pipe. Therefore, it cannot be related to the bubbling downstairs. Answer 2 is also totally incorrect due to the fact it is refering to bubbling in the toilet which is flushed [the "upstairs" toilet], which is not related to the bubbling in the downstairs toilet described in the question. I agree with the explanation in Answer 3, with the exception that I would visually check [with a powerfull flashlight] the vent stack for the downstairs toilet [or at least the viewable section of a shared stack], understanding of course, that unless the vent stack is a perfect straight shot, a visual check would be limited to only the straight run section. In our area, over 95% of houses are single story, and checking the drain/waste vents from the roof is no big deal. On two or three story houses, it may be better to try cleaning the line(s), assuming that adequate cleanouts are available. Many of our older houses were not required to have cleanouts, and we have break into walls or dig earth to install them. Otherwise, IF the client WILL NOT go for the cost of add-on cleanouts, we HAVE to work through the roof vent stack opening. This is not uncommon for our area.

Answer 2

In the human body we digest food into our intestines. Sometimes, pieces of food (bloody sweet corn) does not digest properly and the food backs up your piping system, causing large air bubbles. To clear the bubbles, you must take apart your whole toilet.