Clear a blocked flexi-pipe toilet?

[RrogerD]

Had toilet fitted about 12yrs ago with about a foot or so of flexi-pipe waste. It's been fine for the most part but more recently, about the last year or so, has started backing-up when trying to flush the more solid waste. It will go down eventually, with a bit of plunging of the loo brush.
Anticipating a build-up of limescale, I've tried scraping as far as I can reach into it but still the same. I've also tried kilrock, but no joy. I did try poking an endoscope in and around but am nervous at a) getting it stuck and b) poking a hole in the flexi part.
Any ideas on means of unblocking it? Assuming it is simply a build-up of crud in the ridges of the pipe.

 

[terryplumb]

Very unlikely that a 4 inch flexible waste pipe would suffer from limescale build up. More likely a physical item. Did you ever use those hook on plastic things that hang over the toilet bowl and hold those things that colour the water ? Any kids in the house that may have dropped something in the loo and flushed it ?

 

[RrogerD]

Very unlikely that a 4 inch flexible waste pipe would suffer from limescale build up. More likely a physical item. Did you ever use those hook on plastic things that hang over the toilet bowl and hold those things that colour the water ? Any kids in the house that may have dropped something in the loo and flushed it ?

Thanks for the thoughts.
No, no kids. It's in our en-suite. Just us two middle-aged oldies.
You say unlikely to be limescale but, it's not the first time that I've had my whole forearm deep in the water and around the bend chiselling off the stuff due to poor flow. Not on this loo but definitely on another.
The plastic loo hanger thing, could be. I have seen one half disappearing before and managed to save it just in time.
Surely with the latter though, it would be blocked / restricted fully and not clear with a 'glug' when plunged?
Any other chemical options I could try? Or, is the only solution to disconnect and have a look?

 

[robinbanks]

Nigh impossible something like a USB endoscope will poke a hole in it; the cable just doesn't have enough rigidity - it'd be my first try, to get a look. Is the soil pipe accessible outside (to drill a small hole in if there is no access) and look from the other side?

Notefor camming drains over short lengths I tend to atttach the cam to something stiffer like a bit of single core twin and earth and bend one end into an L, then attach the cam so up on the wire relates to up on the image. It's very disorienting otherwise, to have a cam showing an upside down image on the floor of a pipe that looks like a ceiling

If there isn't anything blocking, I've had good success before now by jamming a nut down the end of a hosepipe and drilling side holes just behind it so the water jets out in various directions, then using it as a drain rod,the water jets helping to break up accumulated solids and flush them away. It's low profile too; doesn't form a bulbous end that can get stuck on things

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Also, your comment about having rescued a half way disappeared loo block holder once implies you use them; perhaps consider not using them?

 

[Elsa TLC]

Very unlikely that a 4 inch flexible waste pipe would suffer from limescale build up. More likely a physical item. Did you ever use those hook on plastic things that hang over the toilet bowl and hold those things that colour the water ? Any kids in the house that may have dropped something in the loo and flushed it ?

It highly likely to be limescale mixed with a cocktail that goes down our loo's.
This obviously depends on the area we live.

Im in West Essex and the limescale seems to be getting worse.

Ive noticed it more this past year than ever before.

These pictures are from two or 3 separate jobs in 2025.

The picture below, was the trap of a toilet pan, majority scaled up.

 

[RrogerD]

It highly likely to be limescale mixed with a cocktail that goes down our loo's.
This obviously depends on the area we live.

Im in West Essex and the limescale seems to be getting worse.

Ive noticed it more this past year than ever before.

These pictures are from two or 3 separate jobs in 2025.

View attachment 390845View attachment 390846

The picture below, was the trap of a toilet pan, majority scaled up.
View attachment 390847

That's unbelievable. Certainly would explain a lot.
Thanks

 

[RrogerD]

Nigh impossible something like a USB endoscope will poke a hole in it; the cable just doesn't have enough rigidity - it'd be my first try, to get a look. Is the soil pipe accessible outside (to drill a small hole in if there is no access) and look from the other side?

Notefor camming drains over short lengths I tend to atttach the cam to something stiffer like a bit of single core twin and earth and bend one end into an L, then attach the cam so up on the wire relates to up on the image. It's very disorienting otherwise, to have a cam showing an upside down image on the floor of a pipe that looks like a ceiling

If there isn't anything blocking, I've had good success before now by jamming a nut down the end of a hosepipe and drilling side holes just behind it so the water jets out in various directions, then using it as a drain rod,the water jets helping to break up accumulated solids and flush them away. It's low profile too; doesn't form a bulbous end that can get stuck on things

-

Also, your comment about having rescued a half way disappeared loo block holder once implies you use them; perhaps consider not using them?

Thanks for the thoughts and tips. I think I'll access the other end, where it meets the soil stack and rod from there. It's only about a metre.
We no longer use the plastic hanger things, because of this.

 

[Elsa TLC]

Vertical cast iron soil blocked

Crystal added but still had to chip away.

 

[Mottie]

I have noticed something similar with ours - an occasional 'big boy' will make the water in the pan rise alarmingly before disappearing with a whoosh - just before it’s about to overflow! I recently fixed a leaking flush valve but the fill valve is cruddy and noisy. My w/c needs completely removing to do anything so later on, I’m going to remove it, fit a new flush and fill valve, replace the flexi pan connector as well as the flexi fill pipe.

 

[Elsa TLC]

If you can avoid the flexible pan connectors then that's what you should do

 

[Mottie]

If you can avoid the flexible pan connectors then that's what you should do

I’d love to. Trouble with mine is that the only way I can fit the toilet is to expand the flexi fully, connect both ends up and slide the whole thing into place, compressing the flexi as the toilet goes into position.

 

[Elsa TLC]

I’d love to. Trouble with mine is that the only way I can fit the toilet is to expand the flexi fully, connect both ends up and slide the whole thing into place, compressing the flexi as the toilet goes into position.

I can see that. These sort of toilets can look better but not great with fitting or maintenance

 

[Nige F]

All this limescale - surely because of " letting it mellow" ?

 

[aveatry]

All this limescale - surely because of " letting it mellow" ?

Isn’t that if its brown flush it down if its yellow let it mellow, if your yellow is causing limescale then you have a bigger problem than slow flush.

 

[Elsa TLC]

All this limescale - surely because of " letting it mellow" ?

I think a big part of the reason.

I also wonder from conversations with customers it could be medication they are taking.