Toilet flush feed flexi pipe?

[akewt]

hello all

i'm fitting a new toilet with a saniflo and concealed cistern.

the probelm i have is the cistern needs to be at a certain height to fit below the window frame. this makes the feed fitting that came with the unit too long. i have a flexible feed pipe which can fit together fine but it bends in such a way that the water will go uphill before reaching the toilet.

the flexi pipe would come out from under the cistern go down a certain way and bend back up on itself (uphill) and then straighten out horizontally and fit into the toilet.

will it be ok if there is a small amount of sitting water in the feed pipe? will it cause problems with pressure?

thanks for any advice.

Kev

EDIT: I ACTUALLY MEAN THE FLUSH PIPE!

 

[Bahco]

Should be ok at mains pressure.

 

[seco services]

you can't have a flush pipe that go's uphill and holds water.
it will intime pull out the back of the pan.
use the flush pipe that came with the cistern and cut it to length, thats why they are longer than you need.

 

[akewt]

this is the problem really. even cut to the shortest length the pipe is too long.

can i ask why it will pull out of the toilet intime? it shouldnt do,its fixed securely both ends and there will be a minimal amount of sitting water.

 

[Bahco]

Is it the flush pipe you are fitting or the water feed pipe into the cistern?

 

[akewt]

its the flush pipe

 

[seco services]

because the flush pipe only fits in the pan by a pushfit seal and if the flexi is able to put pressure on the seal because it hangs down will in time slip out of the pan.
the more you reduce the height of your cistern the less pressure you'll have when you flush.
thats why flush pipes are rigid pipe. and cutting your pipe and its still no good your cistern is to low.

 

[akewt]

right ok, i think this is the confirmation i needed. thanks seco services.

i wasnt too keen on using this custom solution any how.

looks like i may have to make the top of the boxing flush with the window sill which i was trying to avoid!! it aint gonna look pretty!!!

 

[JohnD]

why not use a close-coupled cistern?

 

[akewt]

hi johnD

im not sure what a closed coupled cistern is but i already have the cistern and pan bought from bathstore.

thanks all for you replies