Poor toilet flush

[DIYspanner]

The flush has bother getting rid of even a few sheets of loo roll.

Having inspected the bowl's u bend, it has a rather sharp turn like the shown in the image that I got from a listing on SF.

Is this the norm? Are there any brands that have a smoother casting in the u bend?

 

[foxhole]

That is not an accurate drawing just a basic representation .

 

[CountryFan]

Has it always been a problem or something new? Have you checked the water level in the cistern?

 

[DIYspanner]

That is not an accurate drawing just a basic representation .

Its actually quite accurate. Mine too has a sharp bend on the upper of the bend.

 

[DIYspanner]

Has it always been a problem or something new? Have you checked the water level in the cistern?

Has been an issue for the nearly 4 years I've been in the house.

Its a dual flush and when using the full flush, I keep the button pressed to empty the cistern. If flushing paper and solids, the bowl tends to fill and drain away slowly.

The soil pipe top is in the attic and there's an AAV on it.

 

[foxhole]

AAV may stick

 

[blup]

You will get reduced flow with a bend in the soil pipe near the pan. Modern syphonic push button wc’s are far superior to the ball valve types IMO.

 

[DIYspanner]

I'll investigate further.

 

[DIYspanner]

With the bowl clear, I dumped a couple of buckets of water into the bowl and both went through no bother at all so it seems the profile of the bend is the issue, IE, solids and paper being snagged by the sharp u bend.

 

[Hugh Jaleak]

Has been an issue for the nearly 4 years I've been in the house.

Its a dual flush and when using the full flush, I keep the button pressed to empty the cistern. If flushing paper and solids, the bowl tends to fill and drain away slowly.

The soil pipe top is in the attic and there's an AAV on it.

Take the AAV off and see if there any improvement.

 

[ChrisJP]

You will get reduced flow with a bend in the soil pipe near the pan. Modern syphonic push button wc’s are far superior to the ball valve types IMO.

Modern push button cisterns are NOT syphonic - there is no syphon. Instead the push button opens a valve at the base of the cistern to allow the cistern to drain out and flush the toilet. The means of governing the cistern refill - ball valve or inline float system - is completely separate from the flush and has no bearing on flush efficiency.
Flush efficiency has been degraded by the great reduction in size of modern cisterns, so the do often require two flushes to get the toilet pan empty and clean.