Easy question - replacing a toilet syphon

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My toilet flush stopped working and looks like the diaphram has come lose. My cistern appears to be a Derwent McDee Metro 3-part syphon range. Here is a picture of it.





I've just ordered the following of amazon
http://www.amazon.co.uk/gp/aw/d/B003BNPG6Q

Perhaps I just needed a part rather than the whole thing replaced. Could someone please explain how I replace the one part and where it is located if I can avoid replacing the whole unit.

I have a close coupled toilet system.

Many thanks.
 
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The polythene diaphragm will indeed be split, causing the syphon to fail.
To replace this, the close coupled loo has to be split - i.e the cistern has to be removed from the pan.
So, before you start anything else, see if you can release the wing nuts underneath the cistern, and the water supply can be isolated.
You'll also need a new doughnut washer that seals the two parts of the loo on reassembly.
John :)
 
Hi John - Many thanks for your reply.

I just came back from wickes where I bought a cheaper £5 syphon unit but this is not the same as the more expensive McDee one from amazon.

Excuse my ignorance but why does the whole cistern have to be removed off the wall? I thought if I have the 3 part syphon which a part can be replaced, it doesn't then need the whole unit to be replaced?

The Wikes guy also said the same thing about the donut ring so got all that too.

Thx.
 
In this case you are lucky to have a siphon which can dismantled without removal of the cistern. Simply undo the rings on the siphon itself and it should lift apart. Disengage from the lever arm and remove. The diaphagm can then be replaced and the whole lot reassembled. You can probably do it without turning off the water, however I'd shut off the water and drain the cistern first to be on the safe side.
 
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Unscrew the white retaining ring below the red top to the siphon, the right-hand half on the siphon will slide upwards (with care you may be able to leave the flush link attached).

You will then be able to access the diaphragm & platform.
 
Hi John - Many thanks for your reply.

I just came back from wickes where I bought a cheaper £5 syphon unit but this is not the same as the more expensive McDee one from amazon.

Excuse my ignorance but why does the whole cistern have to be removed off the wall? I thought if I have the 3 part syphon which a part can be replaced, it doesn't then need the whole unit to be replaced?

The Wikes guy also said the same thing about the donut ring so got all that too.

Thx.

Apologies!! And thats before a drink :p
John :)
 
Any idea where I can buy the diaphram onits own from on a Sunday? Wiles don't sell them and am yet to try selco or B&Q and sure the plumbing merchants are all closed.
 
Cut one from a sheet of polythene- I used to use fertiliser bags - but then I`m a country boy ;)c
 
Don't ever remember seeing them in the DIY sheds. Plumbers merchants will sell them in packets of 5 but as its a bank holiday weekend, they'll all be shut.

You can always make one from strong plastic sheet which should get you flushing temporarily until you can get the correct thing. I keep a bit of damp proof membrane for this purpose but a rubble sack may be strong enough especially if you double it up. Make a hole and push it onto the lifter inside the siphon then cut round to give the correct shape. If the old diaphragm is still partly intact, you can leave it in place and lay the temporary repair on top of it. This should give the strength to lift the water when the toilet is flushed.
 


Ok managed to take the diaphram part out without you much problem. Rather annoyingly looks like its a round one I need, thought it was oval. Do you know whether the replacement part I can get is a whole plastic round frame or just the membrane?

How should I the plastic round dial part that goes up and down, out as there doesn't seem to be an easy way to unclip it?

Also when looking under the cistern the wing nuts were dripping slowly with water. Should I do something about that?



Thx.
 
All this "Faffing" around, chuck it away and fit a Flapper Valve instead !

The DIY Sheds are open over the weekend.

31YWCPG5nXL._AA160_.jpg
 
Remove the 'C' link from the top of the siphon.

Cut a new piece of membrane as previously suggested and fit
 
Great, I've Since done this and this now works! Thank you very much for your suggestions!

What can I do about the water leaking from the Wing nuts under the cistern? I'm going to always make sure I can buy these cisterns in replaceable parts.
 
Great, I've Since done this and this now works! Thank you very much for your suggestions!

What can I do about the water leaking from the Wing nuts under the cistern? I'm going to always make sure I can buy these cisterns in replaceable parts.

Can you trace back the leak to the base of the cistern?

It may well be that the large doughnut washer between the cistern and the toilet unit needs replacing.
 

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