R.A.K series 600 Close coupled Toilet - won't stop filling

[CANDYPANDY]

Hello,
I've got the above toilet which is push button and fitted with a Geberit syphon or is it cistern?. It was fitted by professional plumbers just over 2 years ago. The problem now is that when you flush- it will not switch off just continues filling- sounds like niagra falls- driving me round the bend.
I have studied the instructions (pictorial with arrows) but I am very confused about what to do.
The instructions are 2 sided one side installation the other side service-which seems to describe in pictures replace washer and clean seating area with cloth.
Can anybody give a diagnosis on what the likely problem is causing it not to switch off and also give more detailed instructions on carrying out the service.
Thank you

 

[tincup]

Hi
The most likely cause is the washer at the base of the flush valves is not sealing on the cistern nut outlet. The washer if grey in colour is prone to delaminating evident by blisters forming which when punctured bleed. The replacement washer are clear.

HTH

 

[PrenticeBoyofDerry]

Could be the float setting has moved or come loose, if water is over flowing in to pan, wants adjusting.

 

[CANDYPANDY]

Hello,
Firstly tincup could this be the same washer that is mentioned in the pictorial instructions for Service? I am struggling with the part names you mention as non are given in the instructions. Could you come down to idiot level and describe how parts are removed to acess this washer -in the instructions a large column shaped part is removed by simply twisting clockwise or anti-clockwise and the washer is attached to the base of this.
Secondly PrenticeBoyof Derry the procedure you describe seems more complex and me thinks it may be time to call a plumber-could you give any simple instructions to carry out the adjustments that you think may rectify the problem.
Many thanks to both of you for your assistance.

 

[PrenticeBoyofDerry]

Picture Title

• PrenticeBoyofDerry
• 6 Feb 2013
• 1

You could have something that looks like this.
This operates the inlet for water, the float is down at flushing, and rises as water fills the cistern, when float gets to the required level, it will close the water inlet valve.
If the float is set to high or come loose, then water will continue to fill cistern, this will then go in to overflow and pan.
So the round black shaped bell is your float.
The black screw like gauge on the left, clips on to float as in picture.
This may have come out of it's housing and require clipping back in position or may need adjusting to a lower level.

 

[bolshy]

It could also be the body of the flush valve has disengaged from it's base, or snapped off a lug etc. Just get a plumber, it's not a dear job.

 

[FieryJack]

I have a problem similar to this with a Duravit loo and temperamental Geberit syphon.

View media item 62399
The valve that switches off water supply doesn't always kick in and cistern overfills, creating the mini "Niagara" effect described previously. Fiddling with the syphon, ie pressing it up and down, and a good measure of cursing and shouting will after a random number of minutes persuade the blighter to desist, and the water flow stops.

It seems more frequent at peak times, perhaps pressure drops then. A plumber told me our street (in West London) had 3 bar of pressure, so not sure why this should be an issue.

I've had the syphon mechanism replaced 10 months ago and now the problem has re-appeared. I wrote to Geberit tech support but given their non-response, they must have more pressing issues than mine.

If anyone has advice or come across similar, would be grateful for recommended steps to take.

 

[Charnwood]

Your problem is not with the 'syphon' (it's not a syphon, it's a flush valve) but with the inlet valve not functioning properly.

 

[FieryJack]

Thanks. At least now I can describe the problem more accurately.
Should an inlet valve fail within 9 months, or is there a deeper problem here?

 

[Charnwood]

Fail, yes. Fail terminally, no.
It is possible that some debris has accumulated on the washer, a common problem.

Strip it down, clean the washer re-assemble. Might work.