Toilet not flushing.

[Arbu]

My toilet is not flushing well. When I try to flush it only a modest amount of water comes through. If I hold the lever down for 10-15 seconds it works OK after a few attempts. But after flushing the water sometimes continues to flow into the bowl until I come back and turn the lever up to stop this.

I can't see anything wrong. Can I fix this myself or do I need to get a plumber in?

Photo below.

Thanks.

 

[JohnD]

It's usually the syphon flap worn out. You may as well fit a new syphon or modern flush valve such as a Fluidmaster. The cistern has to come off, and very likely the cistern fixing bolts are rusted solid and have to be sawn off. Fit a new doughnut washer, plate and bolts. You will now know why it's worth getting stainless bolts and nuts, and greasing them to avoid seizing or galling.

It not complicated, but tedious and awkward. You will find yourself kneeling on the floor getting cramp in your arms.

If the flush is weak (common on modern low-water-content WCs), you can fit a flapper valve instead of a syphon, it gives the most powerful flush.

If the fill valve is noisy you can change that at the same time.

 

[Hugh Jaleak]

First job would be to isolate the water supply and empty the cistern of water. Then, depending on WC type, if its close coupled, (where cistern sits on top of the pan), then you have to undo the water and overflow connections, then undo (or cut off is corroded), the 2 fixing bolts that hold the cistern to the pan. These will then need to be replaced on reassembly.

If you're lucky and its a 'Low Level' cistern, with a 'Flush pipe' that joins the cistern to the pan, just undo and remove the flush pipe that connects the cistern to the pan. Then undo the big nut underneath that secures the siphon to the cistern, and remove siphon, I'd fit a new siphon, as it will come with new washers, and shouldn't leak when fitted. Reassemble the rest in reverse order, wrap some PTFE tape around the joint between the flush pipe and the siphon tail before doing the flush pipe securing nut back up.

 

[Arbu]

Thanks. The cistern doesn't sit immediately on top of the pan, so it seems this is a "Low Level" cistern and the job should be fairly easy. I can isolate and empty the water fairly easily. And the nut looks as if it can be fairly easily undone (see photo below). So I guess I just need to buy a new siphon, and don't need to worry about removing the cistern. Any pointers on what sort of siphon I should get?

 

[Hugh Jaleak]

2 choices, get a new siphon washer for about 50p, strip down and replace the washer, or change the siphon complete. https://www.screwfix.com/p/opella-dual-flush-siphon-220mm/20824 Could fit a 'Flush Valve' but depending on your water type, my experience is these fail quite quickly in hard water areas, and require replacement once again.

If you're not planning on changing the WC anytime soon, you might be better to bite the bullet and replace with a Dudley 'Turboflush' siphon. These are more expensive than a standard siphon but split, to allow future washer changes without draining the cistern. https://www.screwfix.com/p/thomas-dudley-ltd-turbo-88-duo-flush-siphon-8/6655f

 

[Arbu]

Thanks very much. I have hard water where I live. I'll get the dudley siphon.

 

[Arbu]

Hmm, I've got the siphon and have 95% drained the cistern, but I can't undo the hexagonal white plastic nut under the cistern. I can twist the existing siphon within the cistern and the projecting end of that moves against the nut so the nut isn't stuck on that. It seems to be stuck against the bottom of the cistern. Any suggestions? I don't have a spanner broad enough to grip the nut - perhaps I ought to get one.

 

[durhamplumber]

Hmm, I've got the siphon and have 95% drained the cistern, but I can't undo the hexagonal white plastic nut under the cistern. I can twist the existing siphon within the cistern and the projecting end of that moves against the nut so the nut isn't stuck on that. It seems to be stuck against the bottom of the cistern. Any suggestions? I don't have a spanner broad enough to grip the nut - perhaps I ought to get one.

Hacksaw...use bigger grips...wd40...call a plumber.cry...wack the feker with a hammer.choices!!!!

 

[Hugh Jaleak]

You'll need something to do up the nut again on the new siphon, best to invest in a suitable spanner.

 

[Arbu]

All done now, thanks for everyone's help. I had to buy a new spanner to undo the old nut. I'm inclined not to tighten up the new one again with this - metal on plastic doesn't seem right to me (unless, as I did, you have to to unscrew an old nut). So I have just done it finger tight. I'll keep an eye out for it leaking but it seems good.

 

[HERTS P&D]

If it's not tight then it will leak.

Andy

 

[Hugh Jaleak]

Need to tighten it with the spanner or it'll weep. Just do it up enough to compress the washer to make a seal, it doesn't need to be a strength contest.

 

[Arbu]

OK well it's not leaking from the cistern end, but it is now leaking from the pan end of the connecting pipe. I had to take this off at this end in order to replace the plastic nut at the cistern end. How do I stop it leaking? Should I replace it?

 

[Hugh Jaleak]

For what they cost, replace the flush cone. Once disturbed they dont always seal again, as you've found out.

 

[Arbu]

OK, I got a new flush cone from Screwfix. It had three small rings and one larger one. I was only able to get the first two of the smaller rings into the inlet to the pan. The third one is flush against it. And it leaks, much as it did with the old flush cone. Can I put some sealant over it?