Any experts in water flow around here?!?
Had been having problems with the flush on a lavatory so wanted to
replace the flap valve, but of course no-one seemed to sell just the
valve material so decided to replace the whole siphon system.
However, the toilet concerned seems to be of the double trap siphonic
type (i.e. the rdeuced pressure in the cistern when the thing flushes is
used to reduce pressure in an air chamber around the first ubend to help
'pull' the water from the bowl down - the readers digest complete DIY
manual gives a good description of what is happening if anyone's
interested!). So anyway, I took all the old one out and removed the
"pressure reducing device" from the old siphon, only to find that it
doesn't fit into the new one. On the advice of a local builder, he
suggested trying without it in place and seeing if it would work (we're
intending to replace the whole bathroom later in the year, so that'd
only be a temporary measure!), but unfortunately it doesn't.
Does anyone have any suggestions as to what I could do? Can you get
'pressure reducing devices' that fit current siphons anywhere? Please
don't tell me I need a complete new toilet just for the sake of the
siphon not working!! :-(((
I've been getting poor flush performance from my washdown flush toilet
and had always been impressed with the performance of syphonic pans when
i'd used them in other houses. Last year I went on a search to find one
that might retrofit into our bathroom. I was told that they were no
longer made - possibly due to not meeting some regulation or other. I
suspect you will find it very difficult to get spares therefore and
might have to resort to new compliant one.
I'm wondering what to do with my poor flush. Maybe a cistern installed
in the loft would give it enough momentum to flush away the 'floaters'!!!
Anyone got any tips for improving the flush? I have a simple washdown
pan and a concealed cistern at a little above the height of a close
coupled type cistern.
To Reply directly to my mailbox, change myisp to ntlworld
It's a very common problem. The British seem incapable of making a wash down
toilet which works reliably, with a low level cistern. I've had 5 newly
installed toilets over the years, which did not work. It seems to be a pot
luck system, expensive ones didn't work, most cheap ones did! It may be
worth while to increase the diameter of the down pipe if your tank is
remote. A new syphon is not generally expensive, except in terms of time to
fit and may ease the problem. Console yourself with the thought, that you
are not in the USA, where a common dinner table confession conversation is
"Toilets we have blocked!" Any US diy store has the biggest stock of toilet
plungers that you have ever seen! The UK is not all bad when compared to
There not a lot you can do to improve the flush. Operating the handle
rapidly with a pump action *sometimes* helps to discharge the contents of
the cistern with a bit more force.
Otherwise, on a one-off basis, you can get rid of the "floaters" by pouring
a bucket of water rapidly into the pan.
I've noticed. It seems that most operate with a swirling motion (so
to speak) followed by some kind of siphonic action. The waste exit
from the pan seems to be underneath it and the pan effectively sits on
top of the soil pipe.
To email, substitute .nospam with .gl
Out of morbid interest I lifted the lid on two US toilet cisterns when I
was last there to see how they work.
The first one contained water but no siphon. The handle was linked to a
chain which lifted a plug out of a plughole at the bottom of the
cistern. On the chain was a float device. The plug was fitted so that it
couldn't come away from the vicinity of the hole. As all the water
drained away there was nothing left to keep the plug floating and it
dropped back into its hole. The pan was siphonic. The cistern filled
using a float valve, not quite a ball cock but similar.
The second suprised me more. The inside of the cistern was completely
dry. There was a big metal cylinder taking up almost all of the space
inside the cistern. The flush operated a switch on the cylinder. When
the toilet flushed there was an accompanying "release of compressed air"
sound. The water came into the pan with quite some force, but there
wasn't much of it. I assume the inside of this cylinder filled with
water, but I couldn't figure out exactly what it was or how it worked.
I remember taking a dump in the company loo in California, and the
loos there had water in the bowl nearly up to the seat level - in
normal operation. It was a bit disconcerting sitting on the seat with
water nearly up to your privates.
Which is all very well unless you've got a floater (I imagine).
This was about 10 years ago, and all the loos in that region seemed to
operate on filling the bowl with maximum water. Glad we haven't got
that deal over here.
Sending email to my published email address isn't
guaranteed to reach me.
These are common in California now. Basically the cylinder is a
pressure vessel with a diaphragm and air trapped behind it - similar
concept to an expansion vessel in a heating system here.
The cylinder is filled under mains pressure with a non return valve.
When you operate the flush, it opens a valve to eject the water at
speed into the pan.
To email, substitute .nospam with .gl
By no stretch of the imagination would I claim to be an expert on this
but I did once improve the performance of the flush by adjusting the
inlet pipe. ISTR it was either too long or pushed in too far.
Paul Mc Cann
Do you mean the diaphragm.i.e. looks like a square/oval of flexible plastic
sitting on top of a grid? See illustrations in
I made a temporary replacement from a substantial polythene bag until I
could go to the local hardware shop (not a shed). Ten years later the 'real
thing' is waiting to be fitted.
For the flush syphon, Vitalite margarine tub, big round one, the lid's
about perfect. Trim it down and off ya go.
Whats the stiffness of your old flap valve? Just pick a sheet plastic
to match it. Domestic refuse is as good a place as any to find
suitable. Food trays, that sort of thing.
Can't you just use a disc of polythene cut out of a fertilizer
sack or similar? Buy a new syphon and just use the disc?
You could try a plumbers merchant, taking the device (commonly called
a "bomb") with you... you can also get a tail piece that a bomb will
fit into that screws onto the bottom of your syphon - OK if it will
all still fit in the cistern....
What sort of colour suite is it? It might be saleable when you come
to get rid of it.
Heh....if I could have found a suitable material, that's what I'd have
done....I'll know to make sure I've got something like that on hand next
Yeah - thought of that. Thing is, the existing siphon was circular and
all the new ones were all more rectangular.....hence deciding to attempt
to replace the whole lot.
Anyway, there seems to be a resolution to this story now...see later....
Indeed - found that out the hard way...!
Nah - t'wouldn't have done; I tried it with it as far into the tailpiece
as it would go (which was, incidentally, still quite a tight fit so I
wasn't worried about leakage) and it was too big to sit in the
appropriate place in the toilet basin.
It's a horrible 70's turquoise....yuk!!
Anyway, the resolution seems to have been try a better town than the one
I live in where the 2 DIY sheds (Focus and Homebase) don't stock much
useful. Happened to be in Bristol on Sunday morn and on spec tried the
B+Q there - guess what...they sold the flap valve/diaphram/whatever you
want to call it in the right size for the old siphon. So out came the
new one, and in went the old one with the new valve (and also,
incidentally, with a spring that was on the new siphon but not on the
old one that pushes the thing back down again afres flush that I thought
was a good idea!) and back together it all went. OK, so there's still a
small issue in that I couldn't find a suitable rubber bung for the bomb
to sit on to get a perfect seal, but I used the old (in quite bad shape)
one - since we're going to replace the lot later in the year that'll do
So the moral is, B+Q seem to sell some useful stuff!
They are still obtainable, but (compared to washdown pans) rather
Is there enough water volume in the cistern? Can you increase it,
e.g. by bending the float arm up?
Does the flush start properly, i.e. is the syphon working properly?
Is the pan level and the bowl being washed down properly?
Can the diameter of the pipe between the cistern and pan be increased
Is there an elbow in the pipe rather than a bend?
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.