marshian Posted February 19 Share Posted February 19 I've got three toilets in the house. All have the same concealed cistern arrangements with a reduced water content (6L) and a two step "water saving" flush functionality Am I alone in thinking this reduction in cistern capacity combined with "water saving part flush" doesn't save any water at all because regardless of the requirement Mrs Marshian hits the full flush button every time (because a partial flush doesn't clear all the no'1's and leaves toilet paper behind) If it's No' 2's it frequently needs a full flush twice. I'm wondering If I should fabricate some stainless steel 8 - 10 L cisterns to fit in place of the plastic 6 L max ones. I've definitely got space inside the built in units to fit larger tanks......... Or is this a bad idea and we should consider drink less and reducing the level of fibre in our diets Oh and what EU directive or building regs would I be breaking 😉 Link to comment Share on other sites More sharing options...
saveasteading Posted February 19 Share Posted February 19 6 litres should do it easily, or there is some design flaw? You would expect that a big name manufacturer will have proven the design with EU standard testing 💩 modules. Sometimes the outlet pipe arrangement can slow the flow. Also. Is it clear which button is full or partial flush? It can be counter-intuitive, or it needs to be held down. Or for a concealed system using tiny air pressure pipes, they can be reversed. Link to comment Share on other sites More sharing options...
marshian Posted February 20 Author Share Posted February 20 18 hours ago, saveasteading said: 6 litres should do it easily, or there is some design flaw? You would expect that a big name manufacturer will have proven the design with EU standard testing 💩 modules. Sometimes the outlet pipe arrangement can slow the flow. Also. Is it clear which button is full or partial flush? It can be counter-intuitive, or it needs to be held down. Or for a concealed system using tiny air pressure pipes, they can be reversed. All three loos suffer from similar issues All are within 1 m of the main soil pipe, are direct coupled to 110mm soil pipe (ie not some flexible concertina adaptor) and have decent falls to the soil pipe (considering the short distances involved The two stage button works a cable mechanism - push the large part for partial flush and the small part for a full flush (both parts of the button go down as a result) Partial flush when fitted is approx 3 L full flush is 6 L (I have experimented with increasing the partial flush volume by adjusting the settings but I end up with the unit set to give 6L regardless of button pushing (hardly a water saving feature if you have to set it up that way) The pans are all different makes (each loo was upgraded over a few years) and each time the performance is not as good as the previous close coupled unit with syphon based flusher and a 10 L cistern Hence my thinking that it's not enough water being flushed - increase the cistern size and I can revert the flush to being a two stage again with 4L for a part flush and 8-10 L for a full flush. All the water feeds to the cisterns are gravity fed from loft tank (not mains supplied) none have flow restrictors in the inlet so they do fill up again quite quickly but I'm not seeing how often needing to flush twice is saving any water. Link to comment Share on other sites More sharing options...
saveasteading Posted February 20 Share Posted February 20 (edited) 31 minutes ago, marshian said: I'm not seeing how often needing to flush twice is saving any water. Edited February 20 by saveasteading no comment made but I can't write in the box so will try again Link to comment Share on other sites More sharing options...
saveasteading Posted February 20 Share Posted February 20 32 minutes ago, marshian said: I'm not seeing how often needing to flush twice is saving any water. Quite so. All I can say is the obvious...something is wrong. The common factor is the cistern. Which manufacturer? Link to comment Share on other sites More sharing options...
marshian Posted February 20 Author Share Posted February 20 17 minutes ago, saveasteading said: Quite so. All I can say is the obvious...something is wrong. The common factor is the cistern. Which manufacturer? All different manufacturers (probably all made in same factory) I think we bought one from Soak, one from plumb world and one from Victoria Plumb Link to comment Share on other sites More sharing options...
MAB Posted February 20 Share Posted February 20 (edited) You might find this thread below also of interest:- Toilet not emptying waste completely Edited February 20 by MAB Link to comment Share on other sites More sharing options...
MAB Posted February 20 Share Posted February 20 Interesting below that Thames water reckon that Dual Flush toilets waste more water than they save due to leaks... Dual-flush toilets 'wasting more water than they save. https://www.theguardian.com/environment/2020/sep/29/dual-flush-toilets-wasting-more-water-than-they-save "Toilets specially designed to save water are wasting more than they conserve, the UK’s largest water firm has warned. Campaigners have warned for years that dual-flush toilets, introduced as more efficient alternatives that were expected to use less than half the amount of water per flush, are more prone to leaks. The problem is said to be so great that the costs are outweighing the benefits. “Because there’s so many loos that continuously flow all through the day and night, collectively that water loss is now exceeding the amount of water the dual-flush design should be saving,” said Andrew Tucker, water efficiency manager at Thames Water. “The volume of water loss is getting bigger every day as more people refurbish and retrofit older toilets and as more homes are built, so it’s a growing problem.” “A siphon will not leak whereas an outlet valve – if we look at the figures we’ve got – they could leak within a week of installation. It could be two years but they will leak,” said Jason Parker, the managing director of Thomas Dudley Ltd, one of the UK’s largest plumbing manufacturers. He told the BBC: “If we’re serious about wasting water and we want to stop it, the only way to do that is put a siphon back in.” Link to comment Share on other sites More sharing options...
Post and beam Posted February 20 Share Posted February 20 On 19/02/2024 at 16:22, marshian said: If it's No' 2's it frequently needs a full flush twice. I have exactly the same issue but i think its the pan thats the issue. We have the same cistern in both the bathroom and downstairs WC. (By the way didn't we have the same thread a couple of weeks ago) Our old cheap B&Q pan is fine. The newer, bought online sight unseen vanity set, uses a pan with a shelf. Complete rubbish. As it happens deciding how to deal with a malfunctioning concelaed cistern is causing me headaches at the mo'. How much do you dismantle ? Link to comment Share on other sites More sharing options...
Post and beam Posted February 20 Share Posted February 20 11 minutes ago, MAB said: If we’re serious about wasting water and we want to stop it, the only way to do that is put a siphon back in Now he tells us. But i agree Link to comment Share on other sites More sharing options...
Mr Punter Posted February 20 Share Posted February 20 We once had an old style high level cistern. Nothing would escape it. No turd too big or sticky to resist the torrent from 2m up. No double flushing needed there. 1 Link to comment Share on other sites More sharing options...
Post and beam Posted February 20 Share Posted February 20 2 minutes ago, Mr Punter said: high level cistern I think i want these in the new build, but the thomas crapper things are V V V expensive Link to comment Share on other sites More sharing options...
Mr Punter Posted February 20 Share Posted February 20 12 minutes ago, Post and beam said: I think i want these in the new build, but the thomas crapper things are V V V expensive Maybe one of these https://www.tradingdepot.co.uk/armitage-shanks-conceala2-high-level-cistern-syphon-side-inlet-lever £78 inc. They can go in the loft or boxed in at high level. Link to comment Share on other sites More sharing options...
marshian Posted February 20 Author Share Posted February 20 1 hour ago, Mr Punter said: We once had an old style high level cistern. Nothing would escape it. No turd too big or sticky to resist the torrent from 2m up. No double flushing needed there. I was trying to keep the thread clean (unlike the damn toilets) but you are 100% correct - those old thunder flushes were a pull once and never need to check if it needed another Link to comment Share on other sites More sharing options...
marshian Posted February 20 Author Share Posted February 20 1 hour ago, MAB said: You might find this thread below also of interest:- Toilet not emptying waste completely OK that's a "relief" (sorry) - it seems I'm not alone in finding modern toilets flush volume "piss poor" (sorry again) Link to comment Share on other sites More sharing options...
marshian Posted February 20 Author Share Posted February 20 1 hour ago, MAB said: Interesting below that Thames water reckon that Dual Flush toilets waste more water than they save due to leaks... Dual-flush toilets 'wasting more water than they save. https://www.theguardian.com/environment/2020/sep/29/dual-flush-toilets-wasting-more-water-than-they-save "Toilets specially designed to save water are wasting more than they conserve, the UK’s largest water firm has warned. Campaigners have warned for years that dual-flush toilets, introduced as more efficient alternatives that were expected to use less than half the amount of water per flush, are more prone to leaks. The problem is said to be so great that the costs are outweighing the benefits. “Because there’s so many loos that continuously flow all through the day and night, collectively that water loss is now exceeding the amount of water the dual-flush design should be saving,” said Andrew Tucker, water efficiency manager at Thames Water. “The volume of water loss is getting bigger every day as more people refurbish and retrofit older toilets and as more homes are built, so it’s a growing problem.” “A siphon will not leak whereas an outlet valve – if we look at the figures we’ve got – they could leak within a week of installation. It could be two years but they will leak,” said Jason Parker, the managing director of Thomas Dudley Ltd, one of the UK’s largest plumbing manufacturers. He told the BBC: “If we’re serious about wasting water and we want to stop it, the only way to do that is put a siphon back in.” I disagree with the statement that the flushing mechanism leaks - I've not seen that (yet) my experience is that modern flush valves also incorporate a cistern level overflow that would have previously been out thro the wall from the side of the cistern - as a result you quickly knew you had a ball valve failing and letting by because you could hear it dripping or your neighbour told you!!!! I'm pretty sure that the issue of integral overflows in toilet cisterns is compounded by householders setting the level as high as possible in order to get a little extra water in the cistern and improve the flush (I've done this to try and improve the flush but the extra 500 ml doesn't make much difference) Modern side fill valves seem to last a very short time before the diaphram fails or fails to seal My loft tank has a ball valve to control the fill and has only had one new washer in 40 years of use - I'd say that that mechanism is about as reliable as a Nissan Micra or Toyota Yaris (cockroach cars I call them - incredibly hard to kill) Link to comment Share on other sites More sharing options...
marshian Posted February 20 Author Share Posted February 20 1 hour ago, Post and beam said: As it happens deciding how to deal with a malfunctioning concelaed cistern is causing me headaches at the mo'. How much do you dismantle ? All of mine are easy to access with the front of the unit coming off and giving good access - All are fitted with isolation valves because the fill valves are a regular consumables Link to comment Share on other sites More sharing options...
saveasteading Posted February 21 Share Posted February 21 4 hours ago, Post and beam said: a pan with a shelf. A German one for checking on one's well-being. 2 hours ago, marshian said: the flushing mechanism leaks - I've not seen that (yet) A problem in high lime areas. Link to comment Share on other sites More sharing options...
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