New cistern on old loo?

[JoSeagull]

We had a crack in an old cistern. I replaced it with a smaller ecofriendly dualflo syphon cistern but now the bowl doesn't evacuate very quickly and isn't very effective at all.
I have configured the new syphon to max out but there still isn't enough water getting into the bowl fast enough to get round the S bend.
We have checked the drain outside and it flows freely.
Is the only answer to get a bigger cistern? Any advise would be gratefully received.

 

[Hugh Jaleak]

Problem could well be the old cistern was a 9 litre (2 gallon) flush. Some new cisterns use 6-7 litres per flush. Designed to save water often the opposite happens as it needs to flush twice to clear the pan....

I replaced it with a smaller ecofriendly dualflo syphon cistern

May be the problem, you need a 9 litre flush to clear the pan effectively.

 

[Nige F]

You could get a high level cistern with a long flush pipe - go retro I would change the syphon for a drop valve in your existing one - If youre near Eastbourne - go in the Plumbers Mate off Seaside . They have pretty near every part ever made

 

[JoSeagull]

I would change the syphon for a drop valve in your existing one

I tried filling the cistern and removing the syphon to see whether a dump valve would work but it was still pretty slow to empty - do you think its worth trying the dump valve still or better to just find a 9litre cistern?

 

[YELLERBELLY]

could your old pan be syphonic?

 

[JoSeagull]

could your old pan be syphonic?

Yes I think it is as it has a very sharp narrow S bend. What can i do about it? It worked fine with the old leaking cistern - it was just bigger than this new one with a larger volume and big old syphon diaphragm.

 

[YELLERBELLY]

have you re-fitted the syphonic aspirator bomb ?

 

[JoSeagull]

Thanks Bunny831 for setting me in the right direction.

have you re-fitted the syphonic aspirator bomb ?

There wasn't one in there but i did notice the hole that passes straight down into the S bend and now i'm think the aspirator bomb was missing. It worked because of the larger water volume but now it won't.

I've looked into this a bit today - Its a Royal Doulton pan but i don't know what size aspirator was in there - would a syvac http://www.toolstation.com/documents/catalogue/catalogue37/?hl=91249 fit possibly?

 

[YELLERBELLY]

that's the exact one i fitted to royal d and it worked,i can only suggest you try it

 

[Hugh Jaleak]

The Doulton syphonic pans wont work without the aspirator bomb fitted and airtight! I had 2 in my house, 'Pampas' upstairs and white downstairs, also my parents had a nice 'Pampas' version for some years. If you're unsure, post a photo of the pan, (side view might be better), they're easily recognisable.

The 'bomb' needs to be fitted with an airtight seal into the hole under where the syphon tail sits, through to the middle trap. If not, you'll find the pan will fill with water almost to the brim when flushed, and it'll block more or less straight away. The flush doesnt have the power to clear the pan, it relies on the syphonic action to do that. (Even that doesnt always manage to do the job )

 

[JoSeagull]

The 'bomb' needs to be fitted with an airtight seal into the hole under where the syphon tail sits, through to the middle trap. If not, you'll find the pan will fill with water almost to the brim when flushed, and it'll block more or less straight away. The flush doesnt have the power to clear the pan, it relies on the syphonic action to do that. (Even that doesnt always manage to do the job )

I now realise that the dual flush outlet valve isn't going to work with the aspirator. Not sure which outlet valve would be best? Do you know which Push button drop valve work or syphon would be suitable to work with the syvac aspirator?

Oh and this might be useful for anyone not knowing where to fit the "bomb" - http://www.hmjames.co.uk/d_tech_airex.htm

 

[YELLERBELLY]

Out of interest,what's your cost so far?

 

[JoSeagull]

Out of interest,what's your cost so far?

£50 for the cistern and valves and £13 for the aspirator. Better than replacing the pan i think...

 

[Hugh Jaleak]

Will the original syphon fit in the new cistern? Re washer it if need be.