If water is rising in the bowl immediately after you've already flushed, that means a clog is blocking the water from moving through the toilet drain. If you flush again, there will be even more water that's unable to make it past the clog, and you'll end up with even more flooding from the toilet bowl.
If the water is rising in the toilet, the absolute first thing you should do is remove the toilet tank lid and press the flapper down. The toilet flapper allows water to flow from the tank into the toilet bowl, and pressing it closed will immediately stop the water from rising, preventing a potential overflow.
A clog in the toilet's drain will cause the bowl to overfill with water since the water that normally would exit the bowl is partly or completely obstructed. Some toilets will not overflow when there is a clog, but others will spill over when there is only a partial clog in the drain.
A clog in the toilet, toilet flange, or drain
If you have a clog anywhere in the system, this will prevent water from fully flushing down the toilet. Depending on where the clog is and how severe it is, you'll either be able to remove it on your own or you'll need help from a professional.
If the water level is too low, you may end up with frequent clogs because there isn't enough water to properly flush the toilet. If it's too high, your toilet could become dangerously close to overflowing every time you flush.
Will a toilet eventually unclog itself? It sure would be nice, but it's fairly rare for a toilet's clog to clear up after a few hours. It can happen, but only in select circumstances.
Is it okay to leave a clogged toilet overnight? In most cases, you can leave a clogged toilet overnight. However, calling an emergency plumber near you might be warranted if water starts leaking from the pipes. A simple clog likely won't cause this, but an inexperienced homeowner messing with the plumbing could.
You can use Drano® Clog Removers to unclog a kitchen sink, bathroom sink, shower or clogged bathtub, but DO NOT use them in toilets. For clogged or slow-running drains, apply the product and let it work 15 minutes, then flush with hot water.
Caustic soda is a nasty chemical that can burn, but it's very effective for unclogging toilets. To use this chemical, you need to get some rubber gloves and eye protection. You can pick the chemical from the local hardware or grocery stores. Pour a ¾ gallon of cold water into a bucket, and add 3 cups of caustic soda.
High Water Pressure with Baking Soda and Vinegar
To do this, use a 2:1 ratio of vinegar to baking soda, and mix it into 60 gallons of water. As you pour the water down the drain, use a drain snake or plunger to dislodge debris that is blocking water flow.
Bleach is an effective way to deal with blocked toilet drains as it is a dilute solution of sodium hypochlorite and also contains a high chlorine concentration. Using bleach by itself or mixing it with boiling water are effective ways to unclog a toilet.
Then pull up sharply to disturb the clog and loosen it. Continue vigorously pushing and pulling until the water begins to drain. It may take 15 to 20 cycles before the toilet unclogs. Be patient.
Several gentle pumps will usually work better than a couple of hard pushes. If your clog is going to come out, it should happen in less than 10 minutes. If not, it's time to move on to a snake or call a plumber.
So, let's recap the common reasons why a toilet won't unclog — excessive toilet paper use, non-flushable solids, hard water, and clogs in the main sewer line. Thankfully, they can be prevented via methods like double-flushing, covering the toilet bowl, routine inspections and dealing with tree roots.
After you flush a toilet, the water is pulled from the tank into the bowl. As the water is moved, the floater begins to sink. This activates the toilet fill valve, which stays open until the water level reaches its necessary level.
Toilet fill valves last about 5 years and sometimes longer depending on the quality of the valve, how often the toilet is flushed, and whether the home has hard water. However, like any valve that's constantly exposed to water, a fill valve can eventually clog or begin to leak.
A filling mechanism comprising:
The float valve shuts off the water when the cistern is filled to the desired level. The water level can be adjusted by means of an adjustment rack or the float rod. Lowering the float position lowers the level to which the cistern is filled.
Another common symptom of a faulty fill valve is the constant sound of running water. Troubleshoot by adding a few drops of food coloring to your toilet tank. If you do not see the food coloring leak into the bowl, your fill valve needs to be replaced.