Toilet doesn't completely flush unless obstructed

Question

I'm in North America. I'm having issues with my toilet, and this may be a basic question and I'm not originally from here so not used to how the toilets work here!

When I flush the toilet, it doesn't empty properly. The tank empties out, but not quickly. The water in the bowl doesn't really rise, and it drains slowly, meaning we often have to flush four or five times. At no point is there no water in the bowl.

The odd thing is, and this is what makes me think it may be simple, if I put an object to obstruct the outflow, such as a toilet brush, then the bowl fills up and then completely drains out. (note: the toilet brush is not in any way completely blocking the outflow, it's just partially obstructing it).

Any help would be really appreciated!

Answer 1

Open the toilet tank and have a look inside. When you operate the flush lever, a part inside the tank is supposed to pull on the flush valve at the bottom of the tank. That flush valve should open fully and should stay open for a few seconds, then close when the water in the tank is mostly empty.

Is that happening? It's possible that the flush valve is opening only a little. See if you can adjust or reposition the connection between the flush lever and the flush valve. If they are connected by a ball chain and a clip that attaches to the ball chain, re-position the clip to make the ball chain shorter.

There are two types of water-saving toilets (that I am aware of) that may be giving you a problem. One type is "lever up for liquid waste, lever down for solid waste." See if your toilet flushes differently depending on the direction you press the flush lever.

The second type is "quick press the lever for liquid waste, press and hold the lever for solid waste." Try pressing and holding the flush lever to see if the flushing action is more forceful.

Answer 2

The water in the bowl doesn't really rise, and it drains slowly … At no point is there no water in the bowl.

This is all to be expected if water is not entering the bowl fast enough — instead of the water being pushed through at speed, the inflow only raises the water level causing it to slowly spill out to the drain.

So, you now need to identify why the water is not entering the bowl fast enough. Here are some possibilities:

1. The toilet tank is not as full as it should be (assuming this is a gravity-tank toilet without any pressure vessel). If this is the case, you may need to adjust the fill valve — there is usually a way to raise or lower the float which controls when it shuts off. (Make sure that the water level is not so high that the water spills into the overflow tube, as then it will never shut off.)

2. The flapper or other flush mechanism is not opening fully and allowing water to rush out of the tank. Assuming a flapper (the most common type), it should be lifted up high enough so that you should be able to see into the outflow pipe while the toilet is flushing. If it's not doing this, you may need to replace the flapper, or adjust the length of the chain that links it to the flush lever, or adjust something else that's preventing its free movement.

3. The toilet bowl's water passages are clogged somewhere.

   

   (Image by Wikimedia Commons user SouthHamsian)

   When water enters the bowl from the tank, it does so in two different directions: the rim jets (the visible water flow which washes the entire surface of the bowl) and the siphon jet at the bottom, which creates the momentum that pulls most of the water fully out of the bowl. If the siphon jet is clogged then this could create the problem you describe, because there is both less flow rate and less force directly towards the outlet.

   (I'm not familiar with this problem and do not have advice for you on how to clean it.)