Can anyone give me a bleedingly obvious reason why two identical WCs
with maybe a metre difference in head are performing so differently?

The higher one seems to suck like a ... , and leaves only just enough
water to cover the "S" bend. The other one circulates and leaves a
normal amount of water in the pan

I don't actually want to get too involved (for obvious reasons0 but can
anyone give a few pointers as to why the first seems to have an over
active syphon?




--
geoff

On Mon, 1 Oct 2012 21:31:09 +0100, geoff wrote:


Can anyone give me a bleedingly obvious reason why two identical WCs
with maybe a metre difference in head are performing so differently?

The higher one seems to suck like a ... , and leaves only just enough
water to cover the "S" bend. The other one circulates and leaves a
normal amount of water in the pan

I don't actually want to get too involved (for obvious reasons0 but can
anyone give a few pointers as to why the first seems to have an over
active syphon?

Gravitational pull on the water creating a partial vaccum.

Invert the WC, screwing it to the ceiling can be a quite effective
approach. Some standoff washers would probably be required in order to
balance the siphon action with the mass of water in the pan.

Any infirm or elderly users of the device would probably benefit from
a parachute harness [available from Ebay].

For initial commissioning of the project I would tend to avoid curries
and go toward a high fibre diet.

Until solids are mastered, I would definitley stick to the floor
mounted device for urination purposes.

HN

geoff wrote:
Can anyone give me a bleedingly obvious reason why two identical WCs with
maybe a metre difference in head are performing so differently?

The higher one seems to suck like a ... , and leaves only just enough
water to cover the "S" bend. The other one circulates and leaves a normal
amount of water in the pan

I don't actually want to get too involved (for obvious reasons0 but can
anyone give a few pointers as to why the first seems to have an over active syphon?





Is the stack properly vented? I would guess that the falling water from
the higher loo is capable of exerting a greater suction because the height
of the fall is greater than the lower one. In fact, if water is being
pulled below the trap level in the upper pan, the lower one may be causing
air to be drawn into the soil pipe via the upper pan.

Tim

geoff was thinking very hard :
Can anyone give me a bleedingly obvious reason why two identical WCs with
maybe a metre difference in head are performing so differently?

The higher one seems to suck like a ... , and leaves only just enough water
to cover the "S" bend. The other one circulates and leaves a normal amount of
water in the pan

I don't actually want to get too involved (for obvious reasons0 but can
anyone give a few pointers as to why the first seems to have an over active
syphon?

The flow from the higher one will hit the bowl faster, making the speed
of exit faster. The faster exit once started will be slower to come to
a stop, so more of the water in the bend over flows before it stops.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

When you say a one metre difference in head do you mean the cistern is mounted higher on one than the other?

If so, it seems to me that the water has greater chance to get up to a higher speed from the higher cistern.

In message , Archibald
writes
On Mon, 1 Oct 2012 21:31:09 +0100, geoff wrote:


Can anyone give me a bleedingly obvious reason why two identical WCs
with maybe a metre difference in head are performing so differently?

The higher one seems to suck like a ... , and leaves only just enough
water to cover the "S" bend. The other one circulates and leaves a
normal amount of water in the pan

I don't actually want to get too involved (for obvious reasons0 but can
anyone give a few pointers as to why the first seems to have an over
active syphon?

Gravitational pull on the water creating a partial vaccum.



No **** sherlock

good to see a newbie cutting his milk teeth with a sense of humour

--
geoff

In message
1242013644370821660.533313timdownie2003-nospampleaseyahoo.co.uk@reader80
..eternal-september.org, Tim+
writes
geoff wrote:
Can anyone give me a bleedingly obvious reason why two identical WCs with
maybe a metre difference in head are performing so differently?

The higher one seems to suck like a ... , and leaves only just enough
water to cover the "S" bend. The other one circulates and leaves a normal
amount of water in the pan

I don't actually want to get too involved (for obvious reasons0 but can
anyone give a few pointers as to why the first seems to have an over
active syphon?





Is the stack properly vented? I would guess that the falling water from
the higher loo is capable of exerting a greater suction because the height
of the fall is greater than the lower one. In fact, if water is being
pulled below the trap level in the upper pan, the lower one may be causing
air to be drawn into the soil pipe via the upper pan.

This is something that has changed in the past 12 months since I was
last here (which I should have mentioned). What you are alluding to is a
design problem which would have been there from build.



--
geoff

In message ,
Murmansk writes
When you say a one metre difference in head do you mean the cistern is
mounted higher on one than the other?

If so, it seems to me that the water has greater chance to get up to a
higher speed from the higher cistern.


Well, yes - if it had always been like that, but the upper one worked
like normal last year


--
geoff

"geoff" wrote in message ...


Can anyone give me a bleedingly obvious reason why two identical WCs
with maybe a metre difference in head are performing so differently?

The higher one seems to suck like a ... , and leaves only just enough
water to cover the "S" bend. The other one circulates and leaves a
normal amount of water in the pan

I don't actually want to get too involved (for obvious reasons0 but can
anyone give a few pointers as to why the first seems to have an over
active syphon?


I suggest a descale..... inlet and outlet.

geoff wrote:
In message 1242013644370821660.533313timdownie2003-nospampleaseyahoo.co.uk@reader80
.eternal-september.org, Tim+ writes
geoff wrote:
Can anyone give me a bleedingly obvious reason why two identical WCs with
maybe a metre difference in head are performing so differently?

The higher one seems to suck like a ... , and leaves only just enough
water to cover the "S" bend. The other one circulates and leaves a normal
amount of water in the pan

I don't actually want to get too involved (for obvious reasons0 but can
anyone give a few pointers as to why the first seems to have an over active syphon?





Is the stack properly vented? I would guess that the falling water from
the higher loo is capable of exerting a greater suction because the height
of the fall is greater than the lower one. In fact, if water is being
pulled below the trap level in the upper pan, the lower one may be causing
air to be drawn into the soil pipe via the upper pan.

This is something that has changed in the past 12 months since I was last
here (which I should have mentioned). What you are alluding to is a
design problem which would have been there from build.




Well if its got a Drago (?sp) valve or similar instead of being open vented
the valve may have stuck since you last saw it.

Tim

In message
2006811378370902858.715178timdownie2003-nospampleaseyahoo.co.uk@reader80
..eternal-september.org, Tim+
writes
geoff wrote:
In message
1242013644370821660.533313timdownie2003-nospampleaseyahoo.co.uk@reader80
.eternal-september.org, Tim+ writes
geoff wrote:
Can anyone give me a bleedingly obvious reason why two identical WCs with
maybe a metre difference in head are performing so differently?

The higher one seems to suck like a ... , and leaves only just enough
water to cover the "S" bend. The other one circulates and leaves a normal
amount of water in the pan

I don't actually want to get too involved (for obvious reasons0 but can
anyone give a few pointers as to why the first seems to have an
over active syphon?





Is the stack properly vented? I would guess that the falling water from
the higher loo is capable of exerting a greater suction because the height
of the fall is greater than the lower one. In fact, if water is being
pulled below the trap level in the upper pan, the lower one may be causing
air to be drawn into the soil pipe via the upper pan.

This is something that has changed in the past 12 months since I was last
here (which I should have mentioned). What you are alluding to is a
design problem which would have been there from build.




Well if its got a Drago (?sp) valve or similar instead of being open vented
the valve may have stuck since you last saw it.


I'll google and check

fancy having such a thing named after you, eh ?



--
geoff

geoff wrote:
In message 2006811378370902858.715178timdownie2003-nospampleaseyahoo.co.uk@reader80
.eternal-september.org, Tim+ writes
geoff wrote:
In message 1242013644370821660.533313timdownie2003-nospampleaseyahoo.co.uk@reader80
.eternal-september.org, Tim+ writes
geoff wrote:
Can anyone give me a bleedingly obvious reason why two identical WCs with
maybe a metre difference in head are performing so differently?

The higher one seems to suck like a ... , and leaves only just enough
water to cover the "S" bend. The other one circulates and leaves a normal
amount of water in the pan

I don't actually want to get too involved (for obvious reasons0 but can
anyone give a few pointers as to why the first seems to have an
over active syphon?





Is the stack properly vented? I would guess that the falling water from
the higher loo is capable of exerting a greater suction because the height
of the fall is greater than the lower one. In fact, if water is being
pulled below the trap level in the upper pan, the lower one may be causing
air to be drawn into the soil pipe via the upper pan.

This is something that has changed in the past 12 months since I was last
here (which I should have mentioned). What you are alluding to is a
design problem which would have been there from build.




Well if its got a Drago (?sp) valve or similar instead of being open vented
the valve may have stuck since you last saw it.


I'll google and check

fancy having such a thing named after you, eh ?




Oops. Not Drago but durgo.

https://www.google.co.uk/search?q=du...&client=safari

Tim