Toilet advice

[ban-all-sheds]

OK chums - what are the pros'n'cons of close-coupled vs low-level WCs?

Does close-coupled automatically imply a siphonic trap? (if that's what they're called - the ones where there's some sort of sucking action as well as just water from the cistern involved in the process).

I know about the problems of flap-valves vs siphons in the cistern mechanism, what I'm concerned about is flushing performance, how easily each type is blocked by over-enthusiastic use of toilet tissue, and how easily such blockages are cured, and any other pluses/minuses.

 

[Bahco]

Close coupled loos have less flushing power than LL and from time to time will leave debris (for want of a better word) for all to see .

Many times I have had to go back to reflush and will not have these again in the future

 

[shaggy]

If you are going to compare pan performance then you have to look at cistern volumes. This has changed over the years from a massive 3 gallons (before we went metric), down to 7.5 litres and currently 6 litres.
The other thing is a faster water discharge doesn't necessarily mean better performance. While a valve will discharge water faster than a syphon that doesn't mean it's better. Think about the fall on a sewer pipe; if it's too steep then the water flows too quickly and leaves the solids behind. The same can happen in a pan. I think a lot depends on pan design and there is a good argument for 'try before you buy'.
This is a great subject and I look forward to hearing views from others.

 

[AdamW]

Closed coupled look better in my opinion...

The problem with 6 litre cisterns is that you generally need to flush them twice in my experience... this hardly saves water, 12 litres instead of the 10 litres that would be sufficient.

The high-level toilets are making a comeback in certain circles. My mum saw one in a ritzy bathroom shop a few weeks ago, in steel.

I installed a close-coupled in my bathroom. I found it was a bit of a faff. With a low-level you install pan, install cistern, then connect a pipe between the two. I found that the washers/gaskets that came with my close-coupled one had to compressed tight enough that I was worried for the porcelain. So, it had to be installed twice due to leaking becoming apparent after a few days, between the pan and cistern.

I can't see low-level making ground over close-coupled in the next few years. Close-coupled looks so much nicer for current tastes. Mine has a syphonic valve, not sure about the trap design.

 

[Bahco]

Agree CC look asthetically better than LL but poor flushing is very frustrating.
I believe that this is due not to reduced water volumes but to reduced pressure that CC has.
Best flush I seen was from an old hi level cistern. The pressure of the flush was such that elephant dung would have stood no chance

 

[shaggy]

BAHCO:

Best flush I seen was from an old hi level cistern.

Agreed that it would have more pressure but it was probably also 3 gallons which does make a big difference to performance.

 

[ban-all-sheds]

Assuming that one was prepared to remain in ignorance of the regulations, what is the actual capacity of cisterns?

If I buy a cistern separately from a pan, and say "it's a replacement", I can still have 7.5L...

 

[shaggy]

I've got an Armitage Shanks close-coupled one and inside the cistern the water level is marked by cast-in letters that say 7.5L WL BS 7357. On the outside of the cistern is a sticker that says if the cistern was installed before 1993 then the syphon may be modified to give a 9L flush.
I think if you buy a complete pan and cistern today you can only get a 6L one but you may be able to get a replacement 7.5L one.
I know Wickes sell the cistern separate and I'm going in tomorrow so will have a look for you, as you don't like sheds.

 

[AdamW]

But you will have a whacking big cistern on a tiny little pan.

I wonder if anyone has ever tried installing a 3 gallon cistern in their loft, with a syphonic valve (or even just a flapper) and run a pipe down to the pan directly below? Concealed cistern, with immense pressure.

Problem is, wouldn't there be a good chance of things splashing out of the toilet even with the lid shut?

 

[AdamW]

I've just had a thought. Back in the 80s, I remember many kids TV shows saying to save water by putting a brick in the cistern...

How many cisterns were cracked or smashed in the 80s by kids dropping bricks into them? I reckon it was just a ploy by the Institute of Plumbers

 

[shaggy]

Cistern in loft may be worth a try; it may function as an ascending spray bidet.

 

[PEDANTICVINDICTIVEMAN]

Syphonic toilet pans are no longer sold because they need 9 litre cisterns to make the double trap in the pan operate (sucking action) which isn't actually sucking it's atmospheric pressure (pushing) due to the negative pressure effect caused by the two traps.

 

[shaggy]

Don't you mean just the 6L ones though? I've got a syphonic cistern that does operate on 7.5L not 9L. Wickes do still sell a cheap plastic cistern with a syphon and I've bought one recently.

 

[PEDANTICVINDICTIVEMAN]

Ban all sheds said close coupled with syphonic trap and sucking action, were not talking about the "syphon" fitted inside the cistern, were talking about "double trap syphonic" close coupled toilet suites which need enough water to oprate correctly.

 

[shaggy]

I've read it again PVMan and you're right. I was looking at where he said 'flap valves versus syphons' and thought he meant outlet valve cisterns versus syphonic cisterns so I was talking about cisterns. Back to school for me then; 'read the question properly'