Why Does a Toilet Control System Make Bubbles?

Venting Issues

• People do not think of toilets as producing gases, but they do. The waste system in your house creates sewage gases that are vented off through your plumbing, typically through a roof vent. If you are getting bubbles in your toilet (especially accompanied by a smell) then your gas venting system could be leaking or malfunctioning in other ways. Call in a plumber to check your venting for signs of damage and replace any worn-out pieces.

Flapper Issues

• The flapper is the simple valve in your toilet tank that opens when your toilet flushes, allowing more water to flow into the system. If your toilet bubbles as it is filling up, the flapper valve could be a key reason. Blockages beneath the flapper, a flapper that does not close all the way, and cracks or holes can all potentially cause refill issues. Cleaning and clearing out your flapper may restore normal function, but you may also have to replace the valve entirely.

Pressure Issues

• If your toilet is bubbling when not being used at all, but when another plumbing system is operating, the reason could be pressure issues. Draining a bathtub or using a shower, for example, can force air through your pipes. Air pockets often vent outward, but sometimes they can move in different directions and cause your toilet to bubble. Increasing plumbing venting may solve this issue, but it is not typically a serious problem.

Blockages

• The flapper valve is not the only part of your toilet that can become blocked over time. A blockage in the water pipes or a toilet clog may also cause air bubbles. The flush holes, below the rim of the toilet bowl, can also become blocked. This causes the toilet to drain incorrectly and may increase pressure or bubbling issues. Clean your toilet and remove any clogs to see if this fixes the problem.