Toilet doesn't flush properly

[wadste]

The problem I have is that when the toilet is flushed the water enters the bowl and the level rises slowly to the top. Once it reaches this level it suddenly drains away but does not have the power to completly clear the toilet. I have read about limescale build up and tried pytting a limescale removal liquid in the cistern. Unfortunately, the overflow pipe does not run into the bowl but outside so I can't put it in there. The flapper seems to work OK but I could be wrong. There seems to be some buildup of scale on the inlet holes and my wife used to use the blue toilet blocks as well.
I have run out of ideas as to what to do next so any help would be appreciated.

 

[Burnerman]

As the flush water is entering the bowl but not leaving from there, this indicates a drainage issue, rather than a flush one.
John

 

[wadste]

Hi John,

It does leave the bowl but not until after it has filled to the top. Also, forgot to mention that I did the 'bucket of water' test, i.e. emptied a full bucket of water quickly into the bowl and it emptied just as it should. From this I have assumed that the outflow isn't blocked.

Steve

 

[Burnerman]

Maybe your loo is of the syphonic type, that does allow a certain amount of bowl filling before discharging, but filling up to the rim seems a bit extreme...the bucket of water test is usually sound, too.
Limescale is notoriously hard to shift - you could have reductions in the ceramic passages preventing sufficient flow.
Perhaps you could use a mirror to peek under the rim?
If that seems ok, maybe a new flush mechanism would help.
John

 

[Brigadier]

Have you tried replacing the siphon?

My loo would flush ok, the cistern would fill up until almost to the fill line, then water would start to trickle back into the bowl (internal overflow).

That said, it seems strange that "the water rises until it fills the bowl, then drains away suddenly". I would have thought that there was a "natural level" of water in the bowl, above which point the water would being to drain away, to retain that "natural level". So the sudden drainage seems odd.

When you do the bucket test, is the water (to the cistern) off, and what is the water level in the bowl pre-bucket test, and post-bucket test?

 

[JohnD]

it does sound like it might be a syphonic bowl and trap. Any chance of a pic?

surprisingly, a Harpic tablet for periodic cleaning, as well as one in the bowl, you can put one in the cistern, and if you leave it overnight, sloshing it round with a nylon washing-up brush from time to time, it really does clean the scale deposits off. You may find flakes of scale fall off the sides into the bottom of the cistern, and you can sponge them out to remove.

Also - believe it or not - you can get a Parazone Bleach Block to put in the cistern, and this slowly removes lime scale with every flush, and prevents it reforming. This will help with the waterways under the rim.

p.s. syphonic toilets are not sold any more. They were fashionable in the 1970's as they are very quiet. They were also very expensive. I had one installed in my first house, it cost as much as the rest of the bathroom suite put together. It would be useful to know how old your house is, and if the bathroom looks old but formerly expensive.

 

[kirkgas]

if it is syphonic it will be very quiet, so surely the OP will be able to advise, it may be a vent issue rather than drainage (technically the same thing, but you need to look up to solve a vent issue and down to solve a drainage problem ) if the external vent is blocked the loo will behave like this so it is worth a mention/look as well as all other options mentioned