Our bathroom toilet cistern - fitted when the bathroom was refurbished
in the early 1990's and not touched since - had become very difficult to
flush, and it was pretty obvious that the syphon was shot. It's a
close-coupled toilet with a fairly heavy vitreous cistern, which was
fitted with a conventional lever-operated flush syphon and bottom entry
ball valve, and bottom entry overflow pipe - discharging to the outside
world.

I decided to replace the syphon with a button-operated dual-flush valve
like this
http://www.toolstation.com/shop/Plum...h+Valve/p65429
and the fill valve with one of these:
http://www.toolstation.com/shop/Plum...k+Valve/p32359

The job is now done. [I could write a book about why it took me a whole
afternoon to get it apart, but I won't bore you with that!]

I do have a few questions, though, for future reference - because I have
another toilet in the en-suite which may get the same treatment even
though its flush isn't *too* bad as yet.

The dual-flush valve has its own adjustable overflow pipe, which
discharges into the pan - potentially doing away with the need for an
external overflow. But:
(a) I already had an external overflow which would have been more
trouble than it's worth to disconnect and blank the hole in the bottom
on the cistern, and
(b) I think I'm more likely to notice water dripping from an external
overflow than dripping into the pan - and I'm on a water meter!

So, what do people normally do when doing a refurb which results in 2
overflows? I've set the adjustable one on the new flush valve a bit
*higher* than the original overflow pipe so that it will only discharge
into the pan if the original one can't cope for some reason. Does that
sound reasonable?

The new fill valve is adjustable for height. It has a "critical level"
indicator and the blurb says that this must be at least 1" above the
overflow level. But if I do that, the top of the fill valve is too high
to fit the lid! What am I supposed to do? I could potentially cut a bit
off the overflow pipe - or adjust the new valve's overflow to a lower
level so as to discharge into the pan rather than outside. But the
overflow level would then be dangerously near to the normal fill level -
so it could only over-fill by a tiny amount before overflowing.

So, what's this "critical level" business all about, and what are the
likely consequences of disregarding it?

I imagine that a few of you fit quite a lot of toilets, and must have
come across these issues.
--
Cheers,
Roger
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On 09/01/16 16:23, Roger Mills wrote:
I do have a few questions, though, for future reference - because I have
another toilet in the en-suite which may get the same treatment even
though its flush isn't *too* bad as yet.

I have found these mechanism and indeed much of bathroom plumbing to be
a bit of a Pirates Code. More a sort of guideline than and actual rule book.

IN general I take them and modify them and replace crappy seals with
good ones and with the use of a bit of brainpower and silicone sealant
bugger with them till they work.


--
Future generations will wonder in bemused amazement that the early
twenty-first centurys developed world went into hysterical panic over a
globally average temperature increase of a few tenths of a degree, and,
on the basis of gross exaggerations of highly uncertain computer
projections combined into implausible chains of inference, proceeded to
contemplate a rollback of the industrial age.

Richard Lindzen

On 09/01/2016 16:23, Roger Mills wrote:
Our bathroom toilet cistern - fitted when the bathroom was refurbished
in the early 1990's and not touched since - had become very difficult to
flush, and it was pretty obvious that the syphon was shot. It's a
close-coupled toilet with a fairly heavy vitreous cistern, which was
fitted with a conventional lever-operated flush syphon and bottom entry
ball valve, and bottom entry overflow pipe - discharging to the outside
world.

I decided to replace the syphon with a button-operated dual-flush valve
like this
http://www.toolstation.com/shop/Plum...h+Valve/p65429

and the fill valve with one of these:
http://www.toolstation.com/shop/Plum...k+Valve/p32359


The job is now done. [I could write a book about why it took me a whole
afternoon to get it apart, but I won't bore you with that!]

I do have a few questions, though, for future reference - because I have
another toilet in the en-suite which may get the same treatment even
though its flush isn't *too* bad as yet.

The dual-flush valve has its own adjustable overflow pipe, which
discharges into the pan - potentially doing away with the need for an
external overflow. But:
(a) I already had an external overflow which would have been more
trouble than it's worth to disconnect and blank the hole in the bottom
on the cistern, and
(b) I think I'm more likely to notice water dripping from an external
overflow than dripping into the pan - and I'm on a water meter!

The internal overflow is a backward step IMO, for exactly the reason you
state.

So, what do people normally do when doing a refurb which results in 2
overflows? I've set the adjustable one on the new flush valve a bit
*higher* than the original overflow pipe so that it will only discharge
into the pan if the original one can't cope for some reason. Does that
sound reasonable?

It does.

The new fill valve is adjustable for height. It has a "critical level"
indicator and the blurb says that this must be at least 1" above the
overflow level. But if I do that, the top of the fill valve is too high
to fit the lid! What am I supposed to do? I could potentially cut a bit
off the overflow pipe - or adjust the new valve's overflow to a lower
level so as to discharge into the pan rather than outside. But the
overflow level would then be dangerously near to the normal fill level -
so it could only over-fill by a tiny amount before overflowing.

So, what's this "critical level" business all about, and what are the
likely consequences of disregarding it?

No idea I'm afraid.

I imagine that a few of you fit quite a lot of toilets, and must have
come across these issues.


--
Dave - The Medway Handyman

On 09/01/2016 16:43, David Lang wrote:
On 09/01/2016 16:23, Roger Mills wrote:


The new fill valve is adjustable for height. It has a "critical level"
indicator and the blurb says that this must be at least 1" above the
overflow level. But if I do that, the top of the fill valve is too high
to fit the lid! What am I supposed to do? I could potentially cut a bit
off the overflow pipe - or adjust the new valve's overflow to a lower
level so as to discharge into the pan rather than outside. But the
overflow level would then be dangerously near to the normal fill level -
so it could only over-fill by a tiny amount before overflowing.

So, what's this "critical level" business all about, and what are the
likely consequences of disregarding it?

No idea I'm afraid.


Thanks for your comments. Are there any rules of thumb on what the
minimum vertical distance should be between the normal fill level and
the overflow level?

Mine is currently about 28mm, and this "critical level" mark is also
28mm above the water - making it *level* with the overflow rather than
one inch above it, as specified. If I reduce the overflow level to meet
this requirement, it will be only about 3mm above the normal fill level
- which sounds far too little to me. [I suppose I could lower the fill
level, but this may impact the flush performance.]
--
Cheers,
Roger
____________
Please reply to Newsgroup. Whilst email address is valid, it is seldom
checked.

On Sat, 09 Jan 2016 16:23:28 +0000, Roger Mills
wrote:

Our bathroom toilet cistern - fitted when the bathroom was refurbished
in the early 1990's and not touched since - had become very difficult to
flush, and it was pretty obvious that the syphon was shot. It's a
close-coupled toilet with a fairly heavy vitreous cistern, which was
fitted with a conventional lever-operated flush syphon and bottom entry
ball valve, and bottom entry overflow pipe - discharging to the outside
world.

I decided to replace the syphon with a button-operated dual-flush valve
like this
http://www.toolstation.com/shop/Plum...h+Valve/p65429
and the fill valve with one of these:
http://www.toolstation.com/shop/Plum...k+Valve/p32359

The job is now done. [I could write a book about why it took me a whole
afternoon to get it apart, but I won't bore you with that!]

I do have a few questions, though, for future reference - because I have
another toilet in the en-suite which may get the same treatment even
though its flush isn't *too* bad as yet.

The dual-flush valve has its own adjustable overflow pipe, which
discharges into the pan - potentially doing away with the need for an
external overflow. But:
(a) I already had an external overflow which would have been more
trouble than it's worth to disconnect and blank the hole in the bottom
on the cistern, and
(b) I think I'm more likely to notice water dripping from an external
overflow than dripping into the pan - and I'm on a water meter!

So, what do people normally do when doing a refurb which results in 2
overflows? I've set the adjustable one on the new flush valve a bit
*higher* than the original overflow pipe so that it will only discharge
into the pan if the original one can't cope for some reason. Does that
sound reasonable?

The new fill valve is adjustable for height. It has a "critical level"
indicator and the blurb says that this must be at least 1" above the
overflow level. But if I do that, the top of the fill valve is too high
to fit the lid! What am I supposed to do? I could potentially cut a bit
off the overflow pipe - or adjust the new valve's overflow to a lower
level so as to discharge into the pan rather than outside. But the
overflow level would then be dangerously near to the normal fill level -
so it could only over-fill by a tiny amount before overflowing.

So, what's this "critical level" business all about, and what are the
likely consequences of disregarding it?

I imagine that a few of you fit quite a lot of toilets, and must have
come across these issues.


I have fitted both my loos with that same pair of valves, but as I
didn't bother to RTFM, and just winged it I was blissfully unaware
(until now) of critical levels etc. Only the downstairs cistern has a
conventional "warning pipe" overflow.

I'm sure it will be OK.

--

Graham.

%Profound_observation%

On Saturday, 9 January 2016 16:22:06 UTC, Roger Mills wrote:
The new fill valve is adjustable for height. It has a "critical level"
indicator and the blurb says that this must be at least 1" above the
overflow level. But if I do that, the top of the fill valve is too high
to fit the lid! What am I supposed to do?

I think there has to be a certain height (25 mm?) between the water inlet and the overflow level so that cistern water cannot back-siphon into the mains supply even in an overflow situation. If not, then use a double-check-valve in the supply.

I think BS 6700 and BS 12121 part 2 or 3 "Type B air gap" may apply, or is that for storage tanks not WC cisterns? Anyway the principle is the same.

Owain

On Saturday, 9 January 2016 22:51:05 UTC, wrote:
On Saturday, 9 January 2016 16:22:06 UTC, Roger Mills wrote:
The new fill valve is adjustable for height. It has a "critical level"
indicator and the blurb says that this must be at least 1" above the
overflow level.

I was right.

https://www.wras.co.uk/consumers/res...ritical_level/

The physical or piezometric level of the fluid in any part of the receptacle a minimum of two seconds after closing the water inlet, starting from maximum water level.

Interpretation given in Regulators' Backflow Specification - backflow prevention arrangements and devices: terms relating to backflow prevention

Owain

On 09/01/2016 22:55, wrote:
On Saturday, 9 January 2016 22:51:05 UTC, wrote:
On Saturday, 9 January 2016 16:22:06 UTC, Roger Mills wrote:
The new fill valve is adjustable for height. It has a "critical level"
indicator and the blurb says that this must be at least 1" above the
overflow level.

I was right.

https://www.wras.co.uk/consumers/res...ritical_level/

The physical or piezometric level of the fluid in any part of the receptacle a minimum of two seconds after closing the water inlet, starting from maximum water level.

Interpretation given in Regulators' Backflow Specification - backflow prevention arrangements and devices: terms relating to backflow prevention

Owain

Thanks. In that case, I don't think I'll worry too much. It would take
several things to fail at the same time before there was a problem, and
even so, the pipework is long enough to ensure that even if there were
some backflow, it wouldn't get as far as the public maims.
--
Cheers,
Roger
____________
Please reply to Newsgroup. Whilst email address is valid, it is seldom
checked.