How do I disconnect/connect an overflow pipe?

[Saycheese5]

Hi,

My overflow pipe is broken and all the joints are coming apart.

From the picture, the 21.5mm overflow pipe D is loose where it meets nut C; should solvent cement have been originally applied in that area? What is nut C for? Should I unscrew nut C while holding nut A with a second spanner? B is the thread (a bit blur).

Many thanks for your advice.

 

[Burnerman]

Hold B
Undo C
Overflow will come out upwards after removing A
(cistern empty, of course!)
John

 

[Saycheese5]

Hold B
Undo C
Overflow will come out upwards after removing A
(cistern empty, of course!)
John

Funny enough but the overflow pipe inside the cistern is well secured, of a different shade, a bit thicker and has a water mark to indicate where the water level should reach, meaning that the pipe underneath is a separate pipe, it moves but the one inside the cistern does not move. It's quite an old toilet cistern. I am right to assume I could disconnect only the moving pipe from below without removing nut A and not disturb anything inside the cistern?

 

[Burnerman]

Maybe a picture of the overflow pipe from the inside would help.....it could be telescopic or something?
There's no need for any cemented joints in this assembly.....often enough, the inside of the overflow is sealed by a tapered rubber washer, and pulled tight by A.
The connection of pipe D into B is usually a collet design, and tightening C makes the seal.
Its a simple enough job to renew the existing overflow pipe for less than a tenner but the exact dimensions of the original one can't be guaranteed!
John

 

[Saycheese5]

The connection of pipe D into B is usually a collet design, and tightening C makes the seal.
Its a simple enough job to renew the existing overflow pipe for less than a tenner but the exact dimensions of the original one can't be guaranteed!
John

The external diameter of the overflow inside the cistern is slightly bigger then D, but the internal diameters seem roughly about the same.

Is it normal then that pipe D can be moved and turned slightly by hand even tough nut C is tight?

Can I then remove D from below the cistern without removing anything inside the cistern?

 

[Madrab]

Is this just to tighten up the outlet pipe? The overflow pipe inside the cistern is a separate pipe so loosening everything below the cistern will be fine. Yes it can move a little, it doesn't have to hold any pressure, the pipes usually just a bit of an interference fit with a seal in nut C.

 

[Saycheese5]

Is this just to tighten up the outlet pipe?

The bit of the pipe outside is damaged and 1 of the elbows is loose so I will need to replace the whole overflow pipe from underneath the cistern to and through the outside wall.

Do I need to completely unscrew nut C and if so will it be ok to put back the same seal if it comes out?

Thanks again.

 

[Bosswhite]

It looks like there is some sort of "bodge up" with the overflow pipe, its fixed by silicone not a nut and washer it also appears to have been extended.
you have the choice either get the correct fittings and re run the overflow to the outside using solvent overflow fittings and pipe ( not recommended by Water Authorities these days, wasting water if you do not notice the overflow leaking from the outside)
Or replace the Siphon flush unit with a modern unit ( i.e. Flapper valve) this has its own overflow which will run into the WC Pan letting you know the cistern is overflowing and needs adjustment,the original overflow hole in the cistern can be blanked off with a blank cap that will only cost a few pence. All overflow pipe can then be removed.
This should be the Internal Overflow fitting that needs replacing ( your choice)

 

[Madrab]

Yes it's OK to remove the nut completely. They are usually re-usable unless the seal/nut is damaged.

 

[Saycheese5]

It looks like there is some sort of "bodge up" with the overflow pipe, its fixed by silicone not a nut and washer it also appears to have been extended.

The inlet pipe seems ok, I think it's the picture that makes it look like silicone underneath the water. Thanks for your pic.

...the pipes usually just a bit of an interference fit with a seal in nut C.

Pipe D came out too easily without unscrewing nut C. Unless I misunderstood, I could not see a washer in nut C, so I bought an Overflow Stand Pipe (under £3) as a spare part and there is no seal in the last (final) nut either. Can I put a bit of PTFE tape or something else around the new pipe when inserting it into C so as to make it watertight? Should I avoid cement solvent in that area?

Picture of new Overflow Stand Pipe as a spare below. Out of interest, what is the white ring for (where the arrow is)? Should there have been a seal inside the last nut (top right)? There was none.

 

[denso13]

PTFE is fine, you rarely get a seal with them.

 

[Madrab]

The white ring is just to go on the underside of the cistern allow the nut to spin easily to tighten.

Yes you can use a little tape to increase the fit on the overflow. Mind it doesn't carry any pressure so just the fit inside the pipe should be enough. It should be a sug fit. Measure the inside diameter of the overflow and ensure it's the correct size of outlet pipe you are using.

 

[Saycheese5]

...It should be a sug fit. Measure the inside diameter of the overflow and ensure it's the correct size of outlet pipe you are using.

Inside diameter of stand pipe where thread is, 22mm, and new solvent weld based pipe is 21.5mm, that's why it's a bit loose and last nut seems of little use in this case. If using Push Fit 22mm, it will be secure, but then the problem is, the pipe itself will be too tight for my 2 x 22mm elbows (even with soap) and too tight for the hole in the cavity wall. Only 0.5mm seems to make quite a difference. So it looks like I may have to fiddle a bit with some PTFE tape...

Hopefuly,... should be able to properly weld my 21.5mm pipe inside a 22mm inside diameter 90 degree elbow with cement solvent?

 

[Madrab]

I don't understand, you should have 21.5mm SW elbows to fit the 21.5mm SW pipe, it shouldn't be loose in the fittings.

 

[Saycheese5]

I don't understand, you should have 21.5mm SW elbows to fit the 21.5mm SW pipe, it shouldn't be loose in the fittings.

That's where I got the elbows from:
http://www.wickes.co.uk/Wickes-Overflow-90-Deg-Elbow-22mm/p/431931

The pipes came as described as 21.5mm pipes from elsewhere. I've never done this before, I hope it will work...