Toilet syphon

[DrPhill]

Hi all, my plumbing skills are legendary.

So before I make yet another mess, perhaps someone could help me. Our downstairs toilet syphon diaphragm seems to be going. I have already replaced the one upstairs, so I know the basic theory.

The downstairs loo has a different design where I cannot easily get to the gurt big nut on the underside of the cistern:

Do I need to take the cistern off completely? That would be a pain......

And where can I get a cheap spanner for the 'gurt big nut' on the underside - last time I had to hire one, but maybe it is time I bought one?

Thanks in advance for any help you can give.

 

[Phil Pascoe]

I seem to remember managing to get mine out without dismantling it, but if you have to take the whole thing apart replace it with a syphon that comes apart at the top - they just have a pin through the two parts. If a diaphragm splits again, it's a couple of minutes work - and if it's that easy of course, you'll probably never need to do it.

 

[DrPhill]

Thanks - if (a big if) I am lucky it might already have one of those..... what are the signs of a 'dismantle from above' one?

 

[flying haggis]

from the pic , yes you do need to take the cistern off and it is probably easier to replace the entire syphon mechanism so just cut off the old "gurt big nut" and when you tighten up the new one two bits of wood can be used to tighten it up(hold the wood at each end and sandwich the nut in the middle)

 

[Homers double]

check first to see if the siphon has the capability to be dismantled from the top, some have a twist collar which allows the siphon to be removed to replace the diaphragm, if it can't be taken apart then it's cistern off time it really doesn't take too long to do and I generally use a sliding adjustable grip to remove and replace the big nut.
If you have to remove the cistern Do your self a favour and get a 2 or 3 part siphon (about £17-20) and replacevthe whole thing it'll make life a lot easier next time the diaphragm fails

 

[Distinterior]

Get yourself one of these..... https://www.powertoolsdirect.com/boa-ba ... N4QAvD_BwE

They are so useful for all sorts of things and ideal for loosening " gurt big nuts" such as the type on toilet flush valves.
You will find a 101 other uses for it as well..!

 

[Homers double]

Here a pic of a 2 part siphon, the blue nut twists to release the top of the siphon leaving the stem connected to the cistern

 

[DrPhill]

Get yourself one of these..... https://www.powertoolsdirect.com/boa-ba ... N4QAvD_BwE

They are so useful for all sorts of things and ideal for loosening " gurt big nuts" such as the type on toilet flush valves.
You will find a 101 other uses for it as well..!

Thanks, That does look good - might even help SWMBO to open tight jar lids. Ordered one from ebay as the postage was cheaper.

 

[DrPhill]

Here a pic of a 2 part siphon, the blue nut twists to release the top of the siphon leaving the stem connected to the cistern

Thanks - I do not have one of those though. Cistern off time. :-(

 

[DrPhill]

Cistern needs removing (drat) - to remove the cistern I have:
(1) two wingnuts, one seized
(2) two pozi screws into wall - one with head stripped
(3) plumbing pipe with water inlet - standard brass screw fitting, but thankfully a service 'stopcock'

1: WD40 on the wingnuts (wont be doing job until the weekend when I can get a syphon)
2: Bodger did not use washers. Yahey! - rubber grommet just pulls over screw head screw head will fit through hole in cistern.
3: Spanners I have.

I do not mind a little bodgery with this as the whole bathroom is on the 'to do' list. Just need to get a 'Round Tuit'.

 

[DrPhill]

check first to see if the siphon has the capability to be dismantled from the top, some have a twist collar which allows the siphon to be removed to replace the diaphragm, if it can't be taken apart then it's cistern off time it really doesn't take too long to do and I generally use a sliding adjustable grip to remove and replace the big nut.
If you have to remove the cistern Do your self a favour and get a 2 or 3 part siphon (about £17-20) and replacevthe whole thing it'll make life a lot easier next time the diaphragm fails

Do all syphons fit all cisterns? If so I can order one on ebay before dismantling the cistern......

(Looking at http://www.ebay.co.uk/itm/DERWENT-MACDE ... SwaB5XoLu1)

 

[Phil Pascoe]

There is another design where the top off one side slides into a sleeve on the other then a peg fixes the two together - a different way of achieving the same end. I started using them after spending a whole morning on my back with an unguarded angle grinder cutting the studs off two cisterns. Not funny when you know the harm a kick could cause. They were very expensive cisterns, but P. Nisshead the plumber who installed them used the cheapest possible fittings and as unfortunately is very common, they had seized solid.

You need to check the height of your syphon, and you'll probably need the doughnut seal as well.

 

[DrPhill]

There is another design where the top off one side slides into a sleeve on the other then a peg fixes the two together - a different way of achieving the same end. I started using them after spending a whole morning on my back with an unguarded angle grinder cutting the studs off two cisterns. Not funny when you know the harm a kick could cause. They were very expensive cisterns, but P. Nisshead the plumber who installed them used the cheapest possible fittings and as unfortunately is very common, they had seized solid.

You need to check the height of your syphon, and you'll probably need the doughnut seal as well.

Overflow height ~8"
Top of existing syphon ~10"
Distance from top of syphon to underside of lid ~1"

So a 9" will work?
What is a 'doughnut seal'

 

[AndyT]

You'll find a doughnut washer between the cistern and the pan. Big and squashy.

https://www.toolstation.com/shop/p39353?table=no

 

[DrPhill]

You'll find a doughnut washer between the cistern and the pan. Big and squashy.

https://www.toolstation.com/shop/p39353?table=no

Thanks, ordered one of those too.

You guys are amazingly helpful. My first though on approaching the job was 'oh turd'. I now have ordered the tools and parts and feel a fair bit more optimistic.

 

[Distinterior]

The chances are that the oval/slotted metal washer will be manky as well when you remove the cistern. This kit will do the job if your metal washer is shot..... https://www.toolstation.com/shop/p85615 ... 20coupling You get a complete set in this kit.

 

[DrPhill]

The chances are that the oval/slotted metal washer will be manky as well when you remove the cistern. This kit will do the job if your metal washer is shot..... https://www.toolstation.com/shop/p85615 ... 20coupling You get a complete set in this kit.

Thanks for the tip. I have ordered similar from ebay. If I had ordered everything at once I could probably have found a better deal, but the total cost for parts and tool is running at about 30gbp - far less than a call-out, and I get to learn something new. I may have a doughnut too many (whatever Homer says) but I am sure it will come in handy one day.

 

[whiskywill]

I changed one of mine last weekend. If I'd known then what I know now, I wouldn't have bought a new flush mechanism. The diaphragm is only a piece of heavy duty polythene. But it only cost £8.49 for the flush and a new close coupled cistern fixing kit, so not crying too much.