hi, i have a gravity system in my house. non-pressurized boiler and i have no space to lift my
cold water cystern or hot water tank, i also don't want to buy or run an electric water pump.
due to a leak in the housing, i had to
change my old dual lever monoblock mixer tap, which run beautifully with good warm water flow ( non ceramic).
bought one advertised to
work from 0.5 bar, which is a modern looking single lever mixer tap with pull out spray. now i only get a
trickle of hot water, cold water fine of course. i did change the connecting tails just in case, but they are the
same. i also did take out all the reducers from the new tap. the
hot feeds from a 22mm pipe, the isolation valve is
a 22mm full bore one. there is no air or dirt in the system and the other
warm tap in the house works fine. it is the bathroom tap, a single
lever monoblock mixer.... without me knowing i must have been sold a large-bore
version, although it has these tails, with 5mm connectors and not much bigger pipes to
fit into hot and cold ( unfortunately unbranded, the
shop i bought it from, has closed
years ago, and being a bathroom tap it wouldn't fit in the kitchen anyway)
do i have to install an old-style 2 lever tap with 15mm connectors?
has anybody run into the same problem and found a solution?
is there a a "single lever mixer tap" that would work ?

On Sun, 13 Sep 2020 08:06:04 -0700 (PDT), zvonko kracun
wrote:

hi, i have a gravity system in my house. non-pressurized boiler and i have no space to lift my
cold water cystern or hot water tank, i also don't want to buy or run an electric water pump.
due to a leak in the housing, i had to
change my old dual lever monoblock mixer tap, which run beautifully with good warm water flow ( non ceramic).
bought one advertised to
work from 0.5 bar, which is a modern looking single lever mixer tap with pull out spray. now i only get a
trickle of hot water, cold water fine of course. i did change the connecting tails just in case, but they are the
same. i also did take out all the reducers from the new tap. the
hot feeds from a 22mm pipe, the isolation valve is
a 22mm full bore one. there is no air or dirt in the system and the other
warm tap in the house works fine. it is the bathroom tap, a single
lever monoblock mixer.... without me knowing i must have been sold a large-bore
version, although it has these tails, with 5mm connectors and not much bigger pipes to
fit into hot and cold ( unfortunately unbranded, the
shop i bought it from, has closed
years ago, and being a bathroom tap it wouldn't fit in the kitchen anyway)
do i have to install an old-style 2 lever tap with 15mm connectors?
has anybody run into the same problem and found a solution?
is there a a "single lever mixer tap" that would work ?

We had a similar problem out here in Argentina when we were sold one
of those fancy pull-out taps in place of a bog-standard version. The
water heater here is not a combi boiler and demands a flow of 5.5lpm
in order to trigger the combustion. The ordinary tap would do this so
comfortably that I never saw any need to measure the flow while it was
installed: the pull-out version delivered barely more than 4lpm and
was useless.

We have sidestepped the problem by turning on the kitchen tap, walking
into the utility room and turning on the sink hot tap. The combined
flow kicks the boiler into life and then turning off the utility room
tap allows things to carry on as normal despite the slower water flow.
Ridiculous is it not - and probably not too safe either as I suspect
others on here are about to tell me. But hey - this is Argentina!

I think the fluid friction - or whatever it is called - in the water
line is just too much unless you have a massively higher water
pressure than we do. If the utility room dodge had not worked, the
next step was going to have to be to swap the shower hose (because on
our tap, the flexible connector is nothing more than a repurposed
shower hose) for a shorter length or modify the existing one to be as
short as possible while abandoning any pull-out feature. From trial
and error with the tap partially disassembled I think most of the
friction seems to be in that final hose so maybe a short hose and
pulling out any water filters and aerators in the shower head will
give you back the oomph you need. In my opinion you have nothing to
lose by trying and it might prevent you having to buy a whole new
assembly.

Good luck and do tell what happens!

Nick

On Sunday, September 13, 2020 at 6:33:54 PM UTC+1, Nick Odell wrote:
On Sun, 13 Sep 2020 08:06:04 -0700 (PDT), zvonko
wrote:

hi, i have a gravity system in my house. non-pressurized boiler and i have no space to lift my
cold water cystern or hot water tank, i also don't want to buy or run an electric water pump.
due to a leak in the housing, i had to
change my old dual lever monoblock mixer tap, which run beautifully with good warm water flow ( non ceramic).
bought one advertised to
work from 0.5 bar, which is a modern looking single lever mixer tap with pull out spray. now i only get a
trickle of hot water, cold water fine of course. i did change the connecting tails just in case, but they are the
same. i also did take out all the reducers from the new tap. the
hot feeds from a 22mm pipe, the isolation valve is
a 22mm full bore one. there is no air or dirt in the system and the other
warm tap in the house works fine. it is the bathroom tap, a single
lever monoblock mixer.... without me knowing i must have been sold a large-bore
version, although it has these tails, with 5mm connectors and not much bigger pipes to
fit into hot and cold ( unfortunately unbranded, the
shop i bought it from, has closed
years ago, and being a bathroom tap it wouldn't fit in the kitchen anyway)
do i have to install an old-style 2 lever tap with 15mm connectors?
has anybody run into the same problem and found a solution?
is there a a "single lever mixer tap" that would work ?
We had a similar problem out here in Argentina when we were sold one
of those fancy pull-out taps in place of a bog-standard version. The
water heater here is not a combi boiler and demands a flow of 5.5lpm
in order to trigger the combustion. The ordinary tap would do this so
comfortably that I never saw any need to measure the flow while it was
installed: the pull-out version delivered barely more than 4lpm and
was useless.

We have sidestepped the problem by turning on the kitchen tap, walking
into the utility room and turning on the sink hot tap. The combined
flow kicks the boiler into life and then turning off the utility room
tap allows things to carry on as normal despite the slower water flow.
Ridiculous is it not - and probably not too safe either as I suspect
others on here are about to tell me. But hey - this is Argentina!

I think the fluid friction - or whatever it is called - in the water
line is just too much unless you have a massively higher water
pressure than we do. If the utility room dodge had not worked, the
next step was going to have to be to swap the shower hose (because on
our tap, the flexible connector is nothing more than a repurposed
shower hose) for a shorter length or modify the existing one to be as
short as possible while abandoning any pull-out feature. From trial
and error with the tap partially disassembled I think most of the
friction seems to be in that final hose so maybe a short hose and
pulling out any water filters and aerators in the shower head will
give you back the oomph you need. In my opinion you have nothing to
lose by trying and it might prevent you having to buy a whole new
assembly.

Good luck and do tell what happens!

Nick
thanks nick, you gave me an idea. the supplied hoses are ridiculously long indeed. i had to loop them for installation.
i shall trace and install as short as possible ones , if it works, i post the result. thanks for your help. zk

On 13/09/2020 16:06, zvonko kracun wrote:

hi, i have a gravity system in my house. non-pressurized boiler and i have no space to lift my
cold water cystern or hot water tank, i also don't want to buy or run an electric water pump.
due to a leak in the housing, i had to
change my old dual lever monoblock mixer tap, which run beautifully with good warm water flow ( non ceramic).
bought one advertised to
work from 0.5 bar, which is a modern looking single lever mixer tap with pull out spray. now i only get a
trickle of hot water, cold water fine of course. i did change the connecting tails just in case, but they are the
same. i also did take out all the reducers from the new tap. the


How much hot water pressure do you actually have (i.e. how far about the
tap is the cold water cistern)?


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

In article , zvonko
kracun wrote:
hi, i have a gravity system in my house. non-pressurized boiler and i
have no space to lift my cold water cystern or hot water tank, i also
don't want to buy or run an electric water pump. due to a leak in the
housing, i had to change my old dual lever monoblock mixer tap, which run
beautifully with good warm water flow ( non ceramic). bought one
advertised to work from 0.5 bar, which is a modern looking single lever
mixer tap with pull out spray. now i only get a trickle of hot water,
cold water fine of course. i did change the connecting tails just in
case, but they are the same. i also did take out all the reducers from
the new tap. the hot feeds from a 22mm pipe, the isolation valve is a
22mm full bore one. there is no air or dirt in the system and the other
warm tap in the house works fine. it is the bathroom tap, a single lever
monoblock mixer.... without me knowing i must have been sold a
large-bore version, although it has these tails, with 5mm connectors and
not much bigger pipes to fit into hot and cold ( unfortunately
unbranded, the shop i bought it from, has closed years ago, and being a
bathroom tap it wouldn't fit in the kitchen anyway) do i have to install
an old-style 2 lever tap with 15mm connectors? has anybody run into the
same problem and found a solution? is there a a "single lever mixer tap"
that would work ?

0.5 bar is 16ft of water head. how high above the kitchen is your tank?

--
from KT24 in Surrey, England
"I'd rather die of exhaustion than die of boredom" Thomas Carlyle

zvonko kracun wrote:
hi, i have a gravity system in my house. non-pressurized boiler and i
have no space to lift my
cold water cystern or hot water tank, i also don't want to buy or run an
electric water pump.
due to a leak in the housing, i had to
change my old dual lever monoblock mixer tap, which run beautifully with
good warm water flow ( non ceramic).
bought one advertised to
work from 0.5 bar,

€œTo work€�, not actually to be any good.

Nearly all modern taps are designed with mains pressure HW as that is what
is common in most of the civilised world. Alas, in the UK we have (for
historical reasons) a lot of gravity systems.

which is a modern looking single lever mixer tap with pull out spray. now i only get a
trickle of hot water,

See, its working! ;-)

cold water fine of course. i did change the connecting tails just in case, but they are the
same. i also did take out all the reducers from the new tap. the
hot feeds from a 22mm pipe, the isolation valve is
a 22mm full bore one. there is no air or dirt in the system and the other
warm tap in the house works fine. it is the bathroom tap, a single
lever monoblock mixer.... without me knowing i must have been sold a large-bore
version, although it has these tails, with 5mm connectors and not much bigger pipes to
fit into hot and cold ( unfortunately unbranded, the
shop i bought it from, has closed
years ago, and being a bathroom tap it wouldn't fit in the kitchen anyway)
do i have to install an old-style 2 lever tap with 15mm connectors?
has anybody run into the same problem and found a solution?
is there a a "single lever mixer tap" that would work ?

I think youll be lucky to find a mixer tap with pull out spray head that
is any better. If youre determined to have that kind of tap and youre
not planning on moving house anytime soon consider a move to either a
pressurised system, a pumped system or a combi.

Shortening the tails wont hurt, but I think youll still be disappointed.

Tim


--
Please don't feed the trolls

On Sunday, September 13, 2020 at 9:13:33 PM UTC+1, charles wrote:
In article , zvonko
kracun wrote:
hi, i have a gravity system in my house. non-pressurized boiler and i
have no space to lift my cold water cystern or hot water tank, i also
don't want to buy or run an electric water pump. due to a leak in the
housing, i had to change my old dual lever monoblock mixer tap, which run
beautifully with good warm water flow ( non ceramic). bought one
advertised to work from 0.5 bar, which is a modern looking single lever
mixer tap with pull out spray. now i only get a trickle of hot water,
cold water fine of course. i did change the connecting tails just in
case, but they are the same. i also did take out all the reducers from
the new tap. the hot feeds from a 22mm pipe, the isolation valve is a
22mm full bore one. there is no air or dirt in the system and the other
warm tap in the house works fine. it is the bathroom tap, a single lever
monoblock mixer.... without me knowing i must have been sold a
large-bore version, although it has these tails, with 5mm connectors and
not much bigger pipes to fit into hot and cold ( unfortunately
unbranded, the shop i bought it from, has closed years ago, and being a
bathroom tap it wouldn't fit in the kitchen anyway) do i have to install
an old-style 2 lever tap with 15mm connectors? has anybody run into the
same problem and found a solution? is there a a "single lever mixer tap"
that would work ?
0.5 bar is 16ft of water head. how high above the kitchen is your tank?

--
from KT24 in Surrey, England
"I'd rather die of exhaustion than die of boredom" Thomas Carlyle



yes, tank is 2 meters in hight and 4 meters horizontal away from tap. cistern is
half a meter above tank. my main problem I think now is the length of the tails but especially the pull out spray
which is almost another meter long.
I intend to try a tap without pull out spray and I use very short tails. thanks for the suggestions. zk

zvonko kracun wrote:

yes, tank is 2 meters in hight and 4 meters horizontal away from tap. cistern is
half a meter above tank. my main problem I think now is the length of the tails but especially the pull out spray
which is almost another meter long.
I intend to try a tap without pull out spray and I use very short tails. thanks for the suggestions. zk

Depending upon the construction of the tap, the problem may be
check valves incorporated in each line to prevent them
back-feeding.

These were not needed with the older design of mixer, where the
flows were separate all the way to the nozzle.

Chris
--
Chris J Dixon Nottingham UK
@ChrisJDixon1

Plant amazing Acers.

Chris J Dixon wrote:

Depending upon the construction of the tap, the problem may be
check valves incorporated in each line to prevent them
back-feeding.

These were not needed with the older design of mixer, where the
flows were separate all the way to the nozzle.

I did get a kitchen mixer (the tall inverted 'U' style) with concentric
pipes all the way to the nozzle about 8 years ago, a quick search seems
to say they're not as easy to find now ...

Andy Burns wrote:
Chris J Dixon wrote:

Depending upon the construction of the tap, the problem may be
check valves incorporated in each line to prevent them
back-feeding.

These were not needed with the older design of mixer, where the
flows were separate all the way to the nozzle.

I did get a kitchen mixer (the tall inverted 'U' style) with concentric
pipes all the way to the nozzle about 8 years ago, a quick search seems
to say they're not as easy to find now ...

Yes, I hadn't realised there has been a general change. I wondered
why a new mixer tap I recently installed stays cold longer than the
older one I have at the kitchen sink even though both have under-sink
water heaters.

--
Chris Green
·

On Monday, September 14, 2020 at 8:49:00 AM UTC+1, Andy Burns wrote:
Chris J Dixon wrote:

Depending upon the construction of the tap, the problem may be
check valves incorporated in each line to prevent them
back-feeding.

These were not needed with the older design of mixer, where the
flows were separate all the way to the nozzle.
I did get a kitchen mixer (the tall inverted 'U' style) with concentric
pipes all the way to the nozzle about 8 years ago, a quick search seems
to say they're not as easy to find now ...

thanks chris, can you send a picture of said tap, or a link ? i have almost given up using my new tap. apart from the half meter tails, by design , the spray
pull out, is attached to the smallest of flexi pipes ( 5mm where connected ), it is over one meter long, looped outside and of course both hot and cold are looped inside, to feed the spray, in an extremely small space . considering the possible presence of back feed prevention check-valves i fear i have to buy an old style mixer tap . the only thing which keeps me back is that my other tap in the bathroom is a modern mixer tap with long tails. it branches off from the same warm water feed, installed at similar hight. it does not have a pull out spray..... and this might be the major problem with my new kitchen tap ??
anyway thanks again for your help. zk

zvonko kracun wrote:

can you send a picture of said tap, or a link ?

Here's one which can handle hot pressure down to 0.2 bar (2 metre head)

https://tapstore.com/twin-round-handle-monobloc-sink-mixer-chrome.html

searching for gravity fed kitchen taps, or low pressure kitchen taps
does find a few, but I doubt you'll get a "fancy" one with flexi-hose.

On Monday, September 14, 2020 at 10:26:32 AM UTC+1, Andy Burns wrote:
zvonko kracun wrote:

can you send a picture of said tap, or a link ?
Here's one which can handle hot pressure down to 0.2 bar (2 metre head)

https://tapstore.com/twin-round-handle-monobloc-sink-mixer-chrome.html

searching for gravity fed kitchen taps, or low pressure kitchen taps
does find a few, but I doubt you'll get a "fancy" one with flexi-hose.

great andy, this is excellent. a million thanks. light at the end of the tunnel !!
now comes the big job, persuading my wife, to give up on the good looking modern tap. zk

In article ,
zvonko kracun wrote:
On Monday, September 14, 2020 at 8:49:00 AM UTC+1, Andy Burns wrote:
Chris J Dixon wrote:

Depending upon the construction of the tap, the problem may be
check valves incorporated in each line to prevent them
back-feeding.

These were not needed with the older design of mixer, where the
flows were separate all the way to the nozzle.
I did get a kitchen mixer (the tall inverted 'U' style) with concentric
pipes all the way to the nozzle about 8 years ago, a quick search seems
to say they're not as easy to find now ...

thanks chris, can you send a picture of said tap, or a link ? i have
almost given up using my new tap. apart from the half meter tails, by
design , the spray pull out, is attached to the smallest of flexi pipes
( 5mm where connected ), it is over one meter long, looped outside and of
course both hot and cold are looped inside, to feed the spray, in an
extremely small space . considering the possible presence of back feed
prevention check-valves i fear i have to buy an old style mixer tap . the
only thing which keeps me back is that my other tap in the bathroom is a
modern mixer tap with long tails. it branches off from the same warm
water feed, installed at similar hight. it does not have a pull out
spray..... and this might be the major problem with my new kitchen tap ??
anyway thanks again for your help. zk

Your problem is almost certainly insufficient head for that tap. The length
of the tails will not affect the water pressure.

--
from KT24 in Surrey, England
"I'd rather die of exhaustion than die of boredom" Thomas Carlyle

On Monday, September 14, 2020 at 11:28:34 AM UTC+1, charles wrote:
In article ,
zvonko kracun wrote:
On Monday, September 14, 2020 at 8:49:00 AM UTC+1, Andy Burns wrote:
Chris J Dixon wrote:

Depending upon the construction of the tap, the problem may be
check valves incorporated in each line to prevent them
back-feeding.

These were not needed with the older design of mixer, where the
flows were separate all the way to the nozzle.
I did get a kitchen mixer (the tall inverted 'U' style) with concentric
pipes all the way to the nozzle about 8 years ago, a quick search seems
to say they're not as easy to find now ...

thanks chris, can you send a picture of said tap, or a link ? i have
almost given up using my new tap. apart from the half meter tails, by
design , the spray pull out, is attached to the smallest of flexi pipes
( 5mm where connected ), it is over one meter long, looped outside and of
course both hot and cold are looped inside, to feed the spray, in an
extremely small space . considering the possible presence of back feed
prevention check-valves i fear i have to buy an old style mixer tap . the
only thing which keeps me back is that my other tap in the bathroom is a
modern mixer tap with long tails. it branches off from the same warm
water feed, installed at similar hight. it does not have a pull out
spray..... and this might be the major problem with my new kitchen tap ??
anyway thanks again for your help. zk
Your problem is almost certainly insufficient head for that tap. The length
of the tails will not affect the water pressure.
--
from KT24 in Surrey, England
"I'd rather die of exhaustion than die of boredom" Thomas Carlyle

thanks Charles
i am aware, for that kind of tap i need to move house. seems simpler to buy an old-style tap or find a similar one i have in the bathroom, which is a single lever mixer tap. zk

On 14/09/2020 00:24, zvonko kracun wrote:
On Sunday, September 13, 2020 at 9:13:33 PM UTC+1, charles wrote:
In article , zvonko
kracun wrote:
hi, i have a gravity system in my house. non-pressurized boiler and i
have no space to lift my cold water cystern or hot water tank, i also
don't want to buy or run an electric water pump. due to a leak in the
housing, i had to change my old dual lever monoblock mixer tap, which run
beautifully with good warm water flow ( non ceramic). bought one
advertised to work from 0.5 bar, which is a modern looking single lever
mixer tap with pull out spray. now i only get a trickle of hot water,
cold water fine of course. i did change the connecting tails just in
case, but they are the same. i also did take out all the reducers from
the new tap. the hot feeds from a 22mm pipe, the isolation valve is a
22mm full bore one. there is no air or dirt in the system and the other
warm tap in the house works fine. it is the bathroom tap, a single lever
monoblock mixer.... without me knowing i must have been sold a
large-bore version, although it has these tails, with 5mm connectors and
not much bigger pipes to fit into hot and cold ( unfortunately
unbranded, the shop i bought it from, has closed years ago, and being a
bathroom tap it wouldn't fit in the kitchen anyway) do i have to install
an old-style 2 lever tap with 15mm connectors? has anybody run into the
same problem and found a solution? is there a a "single lever mixer tap"
that would work ?
0.5 bar is 16ft of water head. how high above the kitchen is your tank?

--
from KT24 in Surrey, England
"I'd rather die of exhaustion than die of boredom" Thomas Carlyle



yes, tank is 2 meters in hight and 4 meters horizontal away from tap. cistern is
half a meter above tank. my main problem I think now is the length of the tails but especially the pull out spray

Its the vertical height that matters - the more the better. The
horizontal matters far less, although the less the better.

So it sounds like you have at most 2.5m of head or about 0.25 bar which
us below the minimum for that tap.

So the only options you have are find a new tap that will work at a
lower pressure, or, add a pump.

(pipework changes will make little difference)


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Monday, September 14, 2020 at 11:28:34 AM UTC+1, charles wrote:
In article ,
zvonko kracun wrote:
On Monday, September 14, 2020 at 8:49:00 AM UTC+1, Andy Burns wrote:
Chris J Dixon wrote:

Depending upon the construction of the tap, the problem may be
check valves incorporated in each line to prevent them
back-feeding.

These were not needed with the older design of mixer, where the
flows were separate all the way to the nozzle.
I did get a kitchen mixer (the tall inverted 'U' style) with concentric
pipes all the way to the nozzle about 8 years ago, a quick search seems
to say they're not as easy to find now ...

thanks chris, can you send a picture of said tap, or a link ? i have
almost given up using my new tap. apart from the half meter tails, by
design , the spray pull out, is attached to the smallest of flexi pipes
( 5mm where connected ), it is over one meter long, looped outside and of
course both hot and cold are looped inside, to feed the spray, in an
extremely small space . considering the possible presence of back feed
prevention check-valves i fear i have to buy an old style mixer tap . the
only thing which keeps me back is that my other tap in the bathroom is a
modern mixer tap with long tails. it branches off from the same warm
water feed, installed at similar hight. it does not have a pull out
spray..... and this might be the major problem with my new kitchen tap ??
anyway thanks again for your help. zk
Your problem is almost certainly insufficient head for that tap. The length
of the tails will not affect the water pressure.
--
from KT24 in Surrey, England
"I'd rather die of exhaustion than die of boredom" Thomas Carlyle
thanks john,
i have found one with stated 0.1 bar functionality ( old style, monoblock, two levers, washers, 15mm straight copper feed tails ) and one
0.2 bar single lever mixer, ceramic ( better looking ) . difficult to decide.

charles wrote:
In article ,
zvonko kracun wrote:
On Monday, September 14, 2020 at 8:49:00 AM UTC+1, Andy Burns wrote:
Chris J Dixon wrote:

Depending upon the construction of the tap, the problem may be
check valves incorporated in each line to prevent them
back-feeding.

These were not needed with the older design of mixer, where the
flows were separate all the way to the nozzle.
I did get a kitchen mixer (the tall inverted 'U' style) with concentric
pipes all the way to the nozzle about 8 years ago, a quick search seems
to say they're not as easy to find now ...

thanks chris, can you send a picture of said tap, or a link ? i have
almost given up using my new tap. apart from the half meter tails, by
design , the spray pull out, is attached to the smallest of flexi pipes
( 5mm where connected ), it is over one meter long, looped outside and of
course both hot and cold are looped inside, to feed the spray, in an
extremely small space . considering the possible presence of back feed
prevention check-valves i fear i have to buy an old style mixer tap . the
only thing which keeps me back is that my other tap in the bathroom is a
modern mixer tap with long tails. it branches off from the same warm
water feed, installed at similar hight. it does not have a pull out
spray..... and this might be the major problem with my new kitchen tap ??
anyway thanks again for your help. zk

Your problem is almost certainly insufficient head for that tap. The length
of the tails will not affect the water pressure.


But they will affect flow to a degree. The long hose to the pull-out head
will also add considerably to flow resistance.

Tim
--
Please don't feed the trolls

On 14/09/2020 11:33, zvonko kracun wrote:
On Monday, September 14, 2020 at 11:28:34 AM UTC+1, charles wrote:
In article , zvonko kracun
wrote:
On Monday, September 14, 2020 at 8:49:00 AM UTC+1, Andy Burns
wrote:
Chris J Dixon wrote:

Depending upon the construction of the tap, the problem may
be check valves incorporated in each line to prevent them
back-feeding.

These were not needed with the older design of mixer, where
the flows were separate all the way to the nozzle.
I did get a kitchen mixer (the tall inverted 'U' style) with
concentric pipes all the way to the nozzle about 8 years ago, a
quick search seems to say they're not as easy to find now ...

thanks chris, can you send a picture of said tap, or a link ? i
have almost given up using my new tap. apart from the half meter
tails, by design , the spray pull out, is attached to the
smallest of flexi pipes ( 5mm where connected ), it is over one
meter long, looped outside and of course both hot and cold are
looped inside, to feed the spray, in an extremely small space .
considering the possible presence of back feed prevention
check-valves i fear i have to buy an old style mixer tap . the
only thing which keeps me back is that my other tap in the
bathroom is a modern mixer tap with long tails. it branches off
from the same warm water feed, installed at similar hight. it
does not have a pull out spray..... and this might be the major
problem with my new kitchen tap ?? anyway thanks again for your
help. zk
Your problem is almost certainly insufficient head for that tap.
The length of the tails will not affect the water pressure. -- from
KT24 in Surrey, England "I'd rather die of exhaustion than die of
boredom" Thomas Carlyle

thanks Charles i am aware, for that kind of tap i need to move house.

Not quite that drastic - you could fit a DHW booster pump to raise the
HW pressure. You could change the cylinder to an unvented one that runs
from the cold main, and so does not need a cistern tank at all, and runs
at high pressure directly.

seems simpler to buy an old-style tap or find a similar one i have in
the bathroom, which is a single lever mixer tap. zk


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
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| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Monday, September 14, 2020 at 6:20:42 PM UTC+1, John Rumm wrote:
On 14/09/2020 11:33, zvonko kracun wrote:
On Monday, September 14, 2020 at 11:28:34 AM UTC+1, charles wrote:
In article , zvonko kracun
wrote:
On Monday, September 14, 2020 at 8:49:00 AM UTC+1, Andy Burns
wrote:
Chris J Dixon wrote:

Depending upon the construction of the tap, the problem may
be check valves incorporated in each line to prevent them
back-feeding.

These were not needed with the older design of mixer, where
the flows were separate all the way to the nozzle.
I did get a kitchen mixer (the tall inverted 'U' style) with
concentric pipes all the way to the nozzle about 8 years ago, a
quick search seems to say they're not as easy to find now ...

thanks chris, can you send a picture of said tap, or a link ? i
have almost given up using my new tap. apart from the half meter
tails, by design , the spray pull out, is attached to the
smallest of flexi pipes ( 5mm where connected ), it is over one
meter long, looped outside and of course both hot and cold are
looped inside, to feed the spray, in an extremely small space .
considering the possible presence of back feed prevention
check-valves i fear i have to buy an old style mixer tap . the
only thing which keeps me back is that my other tap in the
bathroom is a modern mixer tap with long tails. it branches off
from the same warm water feed, installed at similar hight. it
does not have a pull out spray..... and this might be the major
problem with my new kitchen tap ?? anyway thanks again for your
help. zk
Your problem is almost certainly insufficient head for that tap.
The length of the tails will not affect the water pressure. -- from
KT24 in Surrey, England "I'd rather die of exhaustion than die of
boredom" Thomas Carlyle

thanks Charles i am aware, for that kind of tap i need to move house.
Not quite that drastic - you could fit a DHW booster pump to raise the
HW pressure. You could change the cylinder to an unvented one that runs
from the cold main, and so does not need a cistern tank at all, and runs
at high pressure directly.
seems simpler to buy an old-style tap or find a similar one i have in
the bathroom, which is a single lever mixer tap. zk
--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/
have just bought a 0.1 bar tap. amazingly.... these are still available. thanks everybody. zk
ps without pull out spray !

On Sunday, September 13, 2020 at 4:06:08 PM UTC+1, zvonko kracun wrote:
hi, i have a gravity system in my house. non-pressurized boiler and i have no space to lift my
cold water cystern or hot water tank, i also don't want to buy or run an electric water pump.
due to a leak in the housing, i had to
change my old dual lever monoblock mixer tap, which run beautifully with good warm water flow ( non ceramic).
bought one advertised to
work from 0.5 bar, which is a modern looking single lever mixer tap with pull out spray. now i only get a
trickle of hot water, cold water fine of course. i did change the connecting tails just in case, but they are the
same. i also did take out all the reducers from the new tap. the
hot feeds from a 22mm pipe, the isolation valve is
a 22mm full bore one. there is no air or dirt in the system and the other
warm tap in the house works fine. it is the bathroom tap, a single
lever monoblock mixer.... without me knowing i must have been sold a large-bore
version, although it has these tails, with 5mm connectors and not much bigger pipes to
fit into hot and cold ( unfortunately unbranded, the
shop i bought it from, has closed
years ago, and being a bathroom tap it wouldn't fit in the kitchen anyway)
do i have to install an old-style 2 lever tap with 15mm connectors?
has anybody run into the same problem and found a solution?
is there a a "single lever mixer tap" that would work ?


A tap rated at 0.5 bar minimum is not going to work in your average house gravity system unless the tank is around 2.5 m above the tap. (unlikely).
It's intended for a mains pressure hot water system.

On 15/09/2020 08:12, harry wrote:
On Sunday, September 13, 2020 at 4:06:08 PM UTC+1, zvonko kracun
wrote:
hi, i have a gravity system in my house. non-pressurized boiler and
i have no space to lift my cold water cystern or hot water tank, i
also don't want to buy or run an electric water pump. due to a leak
in the housing, i had to change my old dual lever monoblock mixer
tap, which run beautifully with good warm water flow ( non
ceramic). bought one advertised to work from 0.5 bar, which is a
modern looking single lever mixer tap with pull out spray. now i
only get a trickle of hot water, cold water fine of course. i did
change the connecting tails just in case, but they are the same. i
also did take out all the reducers from the new tap. the hot feeds
from a 22mm pipe, the isolation valve is a 22mm full bore one.
there is no air or dirt in the system and the other warm tap in the
house works fine. it is the bathroom tap, a single lever monoblock
mixer.... without me knowing i must have been sold a large-bore
version, although it has these tails, with 5mm connectors and not
much bigger pipes to fit into hot and cold ( unfortunately
unbranded, the shop i bought it from, has closed years ago, and
being a bathroom tap it wouldn't fit in the kitchen anyway) do i
have to install an old-style 2 lever tap with 15mm connectors? has
anybody run into the same problem and found a solution? is there a
a "single lever mixer tap" that would work ?


A tap rated at 0.5 bar minimum is not going to work in your average
house gravity system unless the tank is around 2.5 m above the tap.

0.5 bar is ~5m, not 2.5m

(unlikely). It's intended for a mains pressure hot water system.

In a traditional 2 storey house, if you stick the cold tank on a
platform in the loft, then its just about doable. Easier in a Victorian
place with tall ceilings.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Wednesday, September 16, 2020 at 4:30:28 PM UTC+1, John Rumm wrote:
On 15/09/2020 08:12, harry wrote:
On Sunday, September 13, 2020 at 4:06:08 PM UTC+1, zvonko kracun
wrote:
hi, i have a gravity system in my house. non-pressurized boiler and
i have no space to lift my cold water cystern or hot water tank, i
also don't want to buy or run an electric water pump. due to a leak
in the housing, i had to change my old dual lever monoblock mixer
tap, which run beautifully with good warm water flow ( non
ceramic). bought one advertised to work from 0.5 bar, which is a
modern looking single lever mixer tap with pull out spray. now i
only get a trickle of hot water, cold water fine of course. i did
change the connecting tails just in case, but they are the same. i
also did take out all the reducers from the new tap. the hot feeds
from a 22mm pipe, the isolation valve is a 22mm full bore one.
there is no air or dirt in the system and the other warm tap in the
house works fine. it is the bathroom tap, a single lever monoblock
mixer.... without me knowing i must have been sold a large-bore
version, although it has these tails, with 5mm connectors and not
much bigger pipes to fit into hot and cold ( unfortunately
unbranded, the shop i bought it from, has closed years ago, and
being a bathroom tap it wouldn't fit in the kitchen anyway) do i
have to install an old-style 2 lever tap with 15mm connectors? has
anybody run into the same problem and found a solution? is there a
a "single lever mixer tap" that would work ?


A tap rated at 0.5 bar minimum is not going to work in your average
house gravity system unless the tank is around 2.5 m above the tap.
0.5 bar is ~5m, not 2.5m
(unlikely). It's intended for a mains pressure hot water system.
In a traditional 2 storey house, if you stick the cold tank on a
platform in the loft, then its just about doable. Easier in a Victorian
place with tall ceilings.
--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/
thanks john, yes my ceiling is not very high. the CWC is at the highest point possible upstairs.... not high enough it seems.
the replacement tap arrives tomorrow it has a rating of 0.1 bar, which should be the minimum i have. the modern tap ( rated at 0.5 bar ) gave me 1.9 liters per minute.
i will get 4-8 liters per minute with the replacement tap ordered. they published a chart. i shall post results next week when it is fitted.
thanks again. zk

On 16/09/2020 16:46, zvonko kracun wrote:
On Wednesday, September 16, 2020 at 4:30:28 PM UTC+1, John Rumm wrote:
On 15/09/2020 08:12, harry wrote:

A tap rated at 0.5 bar minimum is not going to work in your average
house gravity system unless the tank is around 2.5 m above the tap.

0.5 bar is ~5m, not 2.5m

(unlikely). It's intended for a mains pressure hot water system.

In a traditional 2 storey house, if you stick the cold tank on a
platform in the loft, then its just about doable. Easier in a Victorian
place with tall ceilings.


thanks john, yes my ceiling is not very high. the CWC is at the highest point possible upstairs.... not high enough it seems.
the replacement tap arrives tomorrow it has a rating of 0.1 bar, which should be the minimum i have. the modern tap ( rated at 0.5 bar ) gave me 1.9 liters per minute.
i will get 4-8 liters per minute with the replacement tap ordered. they published a chart. i shall post results next week when it is fitted.
thanks again. zk

Getting good performance from low pressure systems takes a bit of work,
not only the right choice of taps etc, but also large bore pipes (i.e.
22mm minimum) in simple runs with as few sharp bends as possible.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

In article ,
John Rumm wrote:
On 15/09/2020 08:12, harry wrote:
On Sunday, September 13, 2020 at 4:06:08 PM UTC+1, zvonko kracun
wrote:
hi, i have a gravity system in my house. non-pressurized boiler and
i have no space to lift my cold water cystern or hot water tank, i
also don't want to buy or run an electric water pump. due to a leak
in the housing, i had to change my old dual lever monoblock mixer
tap, which run beautifully with good warm water flow ( non
ceramic). bought one advertised to work from 0.5 bar, which is a
modern looking single lever mixer tap with pull out spray. now i
only get a trickle of hot water, cold water fine of course. i did
change the connecting tails just in case, but they are the same. i
also did take out all the reducers from the new tap. the hot feeds
from a 22mm pipe, the isolation valve is a 22mm full bore one.
there is no air or dirt in the system and the other warm tap in the
house works fine. it is the bathroom tap, a single lever monoblock
mixer.... without me knowing i must have been sold a large-bore
version, although it has these tails, with 5mm connectors and not
much bigger pipes to fit into hot and cold ( unfortunately
unbranded, the shop i bought it from, has closed years ago, and
being a bathroom tap it wouldn't fit in the kitchen anyway) do i
have to install an old-style 2 lever tap with 15mm connectors? has
anybody run into the same problem and found a solution? is there a
a "single lever mixer tap" that would work ?


A tap rated at 0.5 bar minimum is not going to work in your average
house gravity system unless the tank is around 2.5 m above the tap.

0.5 bar is ~5m, not 2.5m

(unlikely). It's intended for a mains pressure hot water system.

In a traditional 2 storey house, if you stick the cold tank on a
platform in the loft, then its just about doable. Easier in a Victorian
place with tall ceilings.

I learned water pressure in feet. 32 ft = 1 bar. which equals 9.65m.

--
from KT24 in Surrey, England
"I'd rather die of exhaustion than die of boredom" Thomas Carlyle

Getting good performance from low pressure systems takes a bit of work,
not only the right choice of taps etc, but also large bore pipes (i.e.
22mm minimum) in simple runs with as few sharp bends as possible.

I've not found it necessary to go to that extreme, gravity hot plumbing
is in 22mm as far as the bath tap, then drops to 15mm for the bathroom
basin, and down to kitchen sink and washing machine point.

For the shower I did fit extra 22mm flange from hot tank all with nice
swept curves to feed pump

On Wed, 16 Sep 2020 16:30:28 +0100, John Rumm
wrote:

On 15/09/2020 08:12, harry wrote:
On Sunday, September 13, 2020 at 4:06:08 PM UTC+1, zvonko kracun
wrote:
hi, i have a gravity system in my house. non-pressurized boiler and
i have no space to lift my cold water cystern or hot water tank, i
also don't want to buy or run an electric water pump. due to a leak
in the housing, i had to change my old dual lever monoblock mixer
tap, which run beautifully with good warm water flow ( non
ceramic). bought one advertised to work from 0.5 bar, which is a
modern looking single lever mixer tap with pull out spray. now i
only get a trickle of hot water, cold water fine of course. i did
change the connecting tails just in case, but they are the same. i
also did take out all the reducers from the new tap. the hot feeds
from a 22mm pipe, the isolation valve is a 22mm full bore one.
there is no air or dirt in the system and the other warm tap in the
house works fine. it is the bathroom tap, a single lever monoblock
mixer.... without me knowing i must have been sold a large-bore
version, although it has these tails, with 5mm connectors and not
much bigger pipes to fit into hot and cold ( unfortunately
unbranded, the shop i bought it from, has closed years ago, and
being a bathroom tap it wouldn't fit in the kitchen anyway) do i
have to install an old-style 2 lever tap with 15mm connectors? has
anybody run into the same problem and found a solution? is there a
a "single lever mixer tap" that would work ?


A tap rated at 0.5 bar minimum is not going to work in your average
house gravity system unless the tank is around 2.5 m above the tap.

0.5 bar is ~5m, not 2.5m

(unlikely). It's intended for a mains pressure hot water system.

In a traditional 2 storey house, if you stick the cold tank on a
platform in the loft, then its just about doable. Easier in a Victorian
place with tall ceilings.

This is the water tank almost immediately opposite where I am at the
moment.
https://th.bing.com/th/id/OIP.VHWCY0...j?pid=Api&rs=1

It is a less decorative copy of this main tank in the centre of the
city

https://parabuenosaires.com/wp-conte...6/10/aysa3.jpg


Although both are enormous and hold enough water between them for the
needs of of the city they are nowhere near as tall as many of the
surrounding buildings so nearly everybody has their water pumped up to
the roof and gravity feed from there.

Nick