I'm doing a house renovation, and the hot&cold water feeds to the
showers in the bathroom and ensuite are in 15mm copper. I want to
upgrade to 22mm where possible to get better flow, as the hot water is
from a cylinder with header tank.

My view is that I'd rather install 22mm everwhere where it won't be
easy to replace later, like underneath tiled floors, and behind tiled
walls. There will still be some runs in 15mm (or maybe half inch, as
some of the pipework is very old), but I might replace these
eventually.

Is this a reasonable thing to do? Are there any reasons why I
shouldn't install 22mm where possible (apart from cost, which is not a
huge factor when looking at the whole job)?

On Thursday, 13 December 2018 17:50:00 UTC, Caecilius wrote:
Is this a reasonable thing to do? Are there any reasons why I
shouldn't install 22mm where possible

If you change to unvented or combi, 22mm pipe has greater volume of water to be run off before the hot arrives at the tap.

Owain

Caecilius wrote:

I want to
upgrade to 22mm where possible to get better flow

Any reason not to install a pump at the base of the tank?

Mine has its own 22mm cold feed from the header tank, and a techflange
giving it a dedicated 22mm feed from near the top of the hot tank, these
stay in 22m on the output side of the pump until they reach back up to
the loft, then reduce to 15mm for the trip across to the bathroom and down.

On 13/12/2018 17:49, Caecilius wrote:
I'm doing a house renovation, and the hot&cold water feeds to the
showers in the bathroom and ensuite are in 15mm copper. I want to
upgrade to 22mm where possible to get better flow, as the hot water is
from a cylinder with header tank.

My view is that I'd rather install 22mm everwhere where it won't be
easy to replace later, like underneath tiled floors, and behind tiled
walls. There will still be some runs in 15mm (or maybe half inch, as
some of the pipework is very old), but I might replace these
eventually.

Is this a reasonable thing to do? Are there any reasons why I
shouldn't install 22mm where possible (apart from cost, which is not a
huge factor when looking at the whole job)?

Other than cost, the only other point is that for hot water at least,
you increase the amount of water you need to run off before the hot gets
to the point of use.


--
Cheers,

John.

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

On 13/12/2018 17:49, Caecilius wrote:
I'm doing a house renovation, and the hot&cold water feeds to the
showers in the bathroom and ensuite are in 15mm copper. I want to
upgrade to 22mm where possible to get better flow, as the hot water is
from a cylinder with header tank.

My view is that I'd rather install 22mm everwhere where it won't be
easy to replace later, like underneath tiled floors, and behind tiled
walls. There will still be some runs in 15mm (or maybe half inch, as
some of the pipework is very old), but I might replace these
eventually.

Is this a reasonable thing to do? Are there any reasons why I
shouldn't install 22mm where possible (apart from cost, which is not a
huge factor when looking at the whole job)?


I doubt you would notice any difference at the shower head unless you
increase the pressure by: raising the header tank, converting to mains
pressure or adding a pump. However, it *might* be beneficial to provide
the showers with 15mm dedicated feeds from a 22mm feed from the tank.

On 13/12/2018 18:03, wrote:
On Thursday, 13 December 2018 17:50:00 UTC, Caecilius wrote:
Is this a reasonable thing to do? Are there any reasons why I
shouldn't install 22mm where possible

If you change to unvented or combi, 22mm pipe has greater volume of water to be run off before the hot arrives at the tap.

Is that not the same when using a header tank he already has?

--
Adam

On Thursday, 13 December 2018 19:06:11 UTC, ARW wrote:
If you change to unvented or combi, 22mm pipe has greater volume of water to be run off before the hot arrives at the tap.
Is that not the same when using a header tank he already has?

Yes, but
- the problem is less acute with a tank than with a combi which fires up every time
- with a header tank the larger pipe may be needed to get a useful flow. With a mains pressure system flow will be adequate through a smaller pipe.

Owain

John Rumm Wrote in message:
On 13/12/2018 17:49, Caecilius wrote:
I'm doing a house renovation, and the hot&cold water feeds to the
showers in the bathroom and ensuite are in 15mm copper. I want to
upgrade to 22mm where possible to get better flow, as the hot water is
from a cylinder with header tank.

My view is that I'd rather install 22mm everwhere where it won't be
easy to replace later, like underneath tiled floors, and behind tiled
walls. There will still be some runs in 15mm (or maybe half inch, as
some of the pipework is very old), but I might replace these
eventually.

Is this a reasonable thing to do? Are there any reasons why I
shouldn't install 22mm where possible (apart from cost, which is not a
huge factor when looking at the whole job)?

Other than cost, the only other point is that for hot water at least,
you increase the amount of water you need to run off before the hot gets
to the point of use.



And increase how much hot water you leave in the pipes to go cold
(that you paid the gas? to heat) after you turn the tap etc
off...
--
Jim K


----Android NewsGroup Reader----
http://usenet.sinaapp.com/

On 13/12/2018 17:49, Caecilius wrote:
I'm doing a house renovation, and the hot&cold water feeds to the
showers in the bathroom and ensuite are in 15mm copper. I want to
upgrade to 22mm where possible to get better flow, as the hot water is
from a cylinder with header tank.

My view is that I'd rather install 22mm everwhere where it won't be
easy to replace later, like underneath tiled floors, and behind tiled
walls. There will still be some runs in 15mm (or maybe half inch, as
some of the pipework is very old), but I might replace these
eventually.

Is this a reasonable thing to do? Are there any reasons why I
shouldn't install 22mm where possible (apart from cost, which is not a
huge factor when looking at the whole job)?


It wasn't uncommon to run 3/4" (pre-historic version of 22mm) for both
hot and cold from the tanks to quite close to the points of use.

IIRC our bath might have had 3/4" right to the taps (bath taps are
usually 3/4" threads rather than 1/2" more common on basins)

The only disadvantage is that you have to shift more water to run the
hot though - though with a tank, you can add a circulation device which
primes the pipe - rare but exists in places where the owner is big on
not wasting water.

--
Email does not work

In article ,
wrote:
I doubt you would notice any difference at the shower head unless you
increase the pressure by: raising the header tank, converting to mains
pressure or adding a pump. However, it *might* be beneficial to provide
the showers with 15mm dedicated feeds from a 22mm feed from the tank.

I have an Aqualisa shower designed for 22mm feeds. From a low pressure
header tank system. Brilliant shower - high flow low pressure. Same with
the feeds to the bath. No point in 22mm to a basin etc though. As the taps
themselves will throttle the flow.

--
*When a man opens a car door for his wife, it's either a new car or a new

Dave Plowman London SW
To e-mail, change noise into sound.

Tim Watts Wrote in message:
On 13/12/2018 17:49, Caecilius wrote:
I'm doing a house renovation, and the hot&cold water feeds to the
showers in the bathroom and ensuite are in 15mm copper. I want to
upgrade to 22mm where possible to get better flow, as the hot water is
from a cylinder with header tank.

My view is that I'd rather install 22mm everwhere where it won't be
easy to replace later, like underneath tiled floors, and behind tiled
walls. There will still be some runs in 15mm (or maybe half inch, as
some of the pipework is very old), but I might replace these
eventually.

Is this a reasonable thing to do? Are there any reasons why I
shouldn't install 22mm where possible (apart from cost, which is not a
huge factor when looking at the whole job)?


It wasn't uncommon to run 3/4" (pre-historic version of 22mm) for both
hot and cold from the tanks to quite close to the points of use.

IIRC our bath might have had 3/4" right to the taps (bath taps are
usually 3/4" threads rather than 1/2" more common on basins)

The only disadvantage is that you have to shift more water to run the
hot though - though with a tank, you can add a circulation device which
primes the pipe - rare but exists in places where the owner is big on
not wasting water.


....but small on not wasting energy :-)
--
Jim K


----Android NewsGroup Reader----
http://usenet.sinaapp.com/

On 13/12/2018 17:49, Caecilius wrote:
I'm doing a house renovation, and the hot&cold water feeds to the
showers in the bathroom and ensuite are in 15mm copper. I want to
upgrade to 22mm where possible to get better flow, as the hot water is
from a cylinder with header tank.

My view is that I'd rather install 22mm everwhere where it won't be
easy to replace later, like underneath tiled floors, and behind tiled
walls. There will still be some runs in 15mm (or maybe half inch, as
some of the pipework is very old), but I might replace these
eventually.

Is this a reasonable thing to do? Are there any reasons why I
shouldn't install 22mm where possible (apart from cost, which is not a
huge factor when looking at the whole job)?

I think that the overall pipe 'resistance' is lower even with some
sections of 15mm left in... so do what you said.



--
€œPeople believe certain stories because everyone important tells them,
and people tell those stories because everyone important believes them.
Indeed, when a conventional wisdom is at its fullest strength, ones
agreement with that conventional wisdom becomes almost a litmus test of
ones suitability to be taken seriously.€�

Paul Krugman

On 14/12/2018 08:04, Jim K.. wrote:

The only disadvantage is that you have to shift more water to run the
hot though - though with a tank, you can add a circulation device which
primes the pipe - rare but exists in places where the owner is big on
not wasting water.


...but small on not wasting energy :-)


True that too...

--
Email does not work

On 14/12/2018 09:34, Tim Watts wrote:
On 14/12/2018 08:04, Jim K.. wrote:

The only disadvantage is that you have to shift more water to run the
hot though - though with a tank, you can add a circulation device which
primes the pipe - rare but exists in places where the owner is big on
not wasting water.


...but small on not wasting energy :-)


True that too...

No too bad if you lag the circulation loop well, and have a timer on the
pump to limit its operation to "likely" times of days. Also the heat
loss is into the fabric of the building, and so offsets the load on the
heating in the winter.


--
Cheers,

John.

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

On 13/12/2018 19:16, wrote:
On Thursday, 13 December 2018 19:06:11 UTC, ARW wrote:
If you change to unvented or combi, 22mm pipe has greater volume of water to be run off before the hot arrives at the tap.
Is that not the same when using a header tank he already has?

Yes, but
- the problem is less acute with a tank than with a combi which fires up every time
- with a header tank the larger pipe may be needed to get a useful flow. With a mains pressure system flow will be adequate through a smaller pipe.

although possibly a bit more noisy...


--
Cheers,

John.

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

In article ,
John Rumm wrote:
On 13/12/2018 19:16, wrote:
On Thursday, 13 December 2018 19:06:11 UTC, ARW wrote:
If you change to unvented or combi, 22mm pipe has greater volume of water to be run off before the hot arrives at the tap.
Is that not the same when using a header tank he already has?

Yes, but
- the problem is less acute with a tank than with a combi which fires up every time
- with a header tank the larger pipe may be needed to get a useful flow. With a mains pressure system flow will be adequate through a smaller pipe.

although possibly a bit more noisy...

It also assumes decent mains pressure. Not the case in this part of London.

--
*If a parsley farmer is sued, can they garnish his wages?

Dave Plowman London SW
To e-mail, change noise into sound.

On 14/12/2018 08:04, Jim K.. wrote:
Tim Watts Wrote in message:
On 13/12/2018 17:49, Caecilius wrote:
I'm doing a house renovation, and the hot&cold water feeds to the
showers in the bathroom and ensuite are in 15mm copper. I want to
upgrade to 22mm where possible to get better flow, as the hot water is
from a cylinder with header tank.

My view is that I'd rather install 22mm everwhere where it won't be
easy to replace later, like underneath tiled floors, and behind tiled
walls. There will still be some runs in 15mm (or maybe half inch, as
some of the pipework is very old), but I might replace these
eventually.

Is this a reasonable thing to do? Are there any reasons why I
shouldn't install 22mm where possible (apart from cost, which is not a
huge factor when looking at the whole job)?


It wasn't uncommon to run 3/4" (pre-historic version of 22mm) for both
hot and cold from the tanks to quite close to the points of use.

IIRC our bath might have had 3/4" right to the taps (bath taps are
usually 3/4" threads rather than 1/2" more common on basins)

The only disadvantage is that you have to shift more water to run the
hot though - though with a tank, you can add a circulation device which
primes the pipe - rare but exists in places where the owner is big on
not wasting water.


...but small on not wasting energy :-)


The circulation pump would normally be on a timer.

Although for filling a bath then there is the old fashioned way of
putting in the plug, turning on the hot tap and letting the first few
litres of cold water go into the bath before the hot water arrives and
mixes with the cold water.

--
Adam

On 14/12/2018 19:20, ARW wrote:
for filling a bath then there is the old fashioned way of putting in the
plug, turning on the hot tap and letting the first few litres of cold
water go into the bath before the hot water arrives and mixes with the
cold water.

Asssuming you do not have a back boiler or a combi, in which case there
isnt any *hot* water. Just a slow trickle of slightly warm water.


--
Outside of a dog, a book is a man's best friend. Inside of a dog it's
too dark to read.

Groucho Marx

On 15/12/2018 07:13, The Natural Philosopher wrote:
On 14/12/2018 19:20, ARW wrote:
for filling a bath then there is the old fashioned way of putting in
the plug, turning on the hot tap and letting the first few litres of
cold water go into the bath before the hot water arrives and mixes
with the cold water.

Asssuming you do not have a back boiler or a combi, in which case there
isnt any *hot* water. Just a slow trickle of slightly warm water.



I have torrents of hot water - enough for 2 bathrooms. But I did not
cheap out when I got mine.

The only real "fault" in a combi that I have observed is that if you
have a run on baths in the morning (like 3 end to end) you of course
lose heating.

But having mains pressure hot water, endless hot water and no storage
tanks makes up for it.

--
Email does not work

On 13/12/2018 18:03, wrote:
On Thursday, 13 December 2018 17:50:00 UTC, Caecilius wrote:
Is this a reasonable thing to do? Are there any reasons why I
shouldn't install 22mm where possible

If you change to unvented or combi, 22mm pipe has greater volume of water to be run off before the hot arrives at the tap.

Owain

Just what I was going to say. DAMHIK.

ARW Wrote in message:
On 14/12/2018 08:04, Jim K.. wrote:
Tim Watts Wrote in message:
On 13/12/2018 17:49, Caecilius wrote:
I'm doing a house renovation, and the hot&cold water feeds to the
showers in the bathroom and ensuite are in 15mm copper. I want to
upgrade to 22mm where possible to get better flow, as the hot water is
from a cylinder with header tank.

My view is that I'd rather install 22mm everwhere where it won't be
easy to replace later, like underneath tiled floors, and behind tiled
walls. There will still be some runs in 15mm (or maybe half inch, as
some of the pipework is very old), but I might replace these
eventually.

Is this a reasonable thing to do? Are there any reasons why I
shouldn't install 22mm where possible (apart from cost, which is not a
huge factor when looking at the whole job)?


It wasn't uncommon to run 3/4" (pre-historic version of 22mm) for both
hot and cold from the tanks to quite close to the points of use.

IIRC our bath might have had 3/4" right to the taps (bath taps are
usually 3/4" threads rather than 1/2" more common on basins)

The only disadvantage is that you have to shift more water to run the
hot though - though with a tank, you can add a circulation device which
primes the pipe - rare but exists in places where the owner is big on
not wasting water.


...but small on not wasting energy :-)


The circulation pump would normally be on a timer.

Mmm so no hot water unless your demands are in sync with the timer?

Plus the heat lost from the water in the circulation loop
(whether the timer's on or off)?


Although for filling a bath then there is the old fashioned way of
putting in the plug, turning on the hot tap and letting the first few
litres of cold water go into the bath before the hot water arrives and
mixes with the cold water.

Indeed! Before you add even more cold water as it's still too
bloody hot to get into "as poured"...


--
Jim K


----Android NewsGroup Reader----
http://usenet.sinaapp.com/

On 18/12/2018 21:05, Jim K.. wrote:
ARW Wrote in message:
On 14/12/2018 08:04, Jim K.. wrote:
Tim Watts Wrote in message:
On 13/12/2018 17:49, Caecilius wrote:
I'm doing a house renovation, and the hot&cold water feeds to the
showers in the bathroom and ensuite are in 15mm copper. I want to
upgrade to 22mm where possible to get better flow, as the hot water is
from a cylinder with header tank.

My view is that I'd rather install 22mm everwhere where it won't be
easy to replace later, like underneath tiled floors, and behind tiled
walls. There will still be some runs in 15mm (or maybe half inch, as
some of the pipework is very old), but I might replace these
eventually.

Is this a reasonable thing to do? Are there any reasons why I
shouldn't install 22mm where possible (apart from cost, which is not a
huge factor when looking at the whole job)?


It wasn't uncommon to run 3/4" (pre-historic version of 22mm) for both
hot and cold from the tanks to quite close to the points of use.

IIRC our bath might have had 3/4" right to the taps (bath taps are
usually 3/4" threads rather than 1/2" more common on basins)

The only disadvantage is that you have to shift more water to run the
hot though - though with a tank, you can add a circulation device which
primes the pipe - rare but exists in places where the owner is big on
not wasting water.


...but small on not wasting energy :-)


The circulation pump would normally be on a timer.

Mmm so no hot water unless your demands are in sync with the timer?

Hot water any time you like. Hot water with no delay when the timer is
active.

Plus the heat lost from the water in the circulation loop
(whether the timer's on or off)?

Lag it dear liza ;-)


--
Cheers,

John.

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

John Rumm Wrote in message:
On 18/12/2018 21:05, Jim K.. wrote:
ARW Wrote in message:
On 14/12/2018 08:04, Jim K.. wrote:
Tim Watts Wrote in message:
On 13/12/2018 17:49, Caecilius wrote:
I'm doing a house renovation, and the hot&cold water feeds to the
showers in the bathroom and ensuite are in 15mm copper. I want to
upgrade to 22mm where possible to get better flow, as the hot water is
from a cylinder with header tank.

My view is that I'd rather install 22mm everwhere where it won't be
easy to replace later, like underneath tiled floors, and behind tiled
walls. There will still be some runs in 15mm (or maybe half inch, as
some of the pipework is very old), but I might replace these
eventually.

Is this a reasonable thing to do? Are there any reasons why I
shouldn't install 22mm where possible (apart from cost, which is not a
huge factor when looking at the whole job)?


It wasn't uncommon to run 3/4" (pre-historic version of 22mm) for both
hot and cold from the tanks to quite close to the points of use.

IIRC our bath might have had 3/4" right to the taps (bath taps are
usually 3/4" threads rather than 1/2" more common on basins)

The only disadvantage is that you have to shift more water to run the
hot though - though with a tank, you can add a circulation device which
primes the pipe - rare but exists in places where the owner is big on
not wasting water.


...but small on not wasting energy :-)


The circulation pump would normally be on a timer.

Mmm so no hot water unless your demands are in sync with the timer?

Hot water any time you like. Hot water with no delay when the timer is
active.

Plus the heat lost from the water in the circulation loop
(whether the timer's on or off)?

Lag it dear liza ;-)

With which 100% efficient lagging should I lag it dear henry?
--
Jim K


----Android NewsGroup Reader----
http://usenet.sinaapp.com/

On 18/12/2018 22:49, Jim K.. wrote:
John Rumm Wrote in message:
On 18/12/2018 21:05, Jim K.. wrote:
ARW Wrote in message:
On 14/12/2018 08:04, Jim K.. wrote:
Tim Watts Wrote in message:
On 13/12/2018 17:49, Caecilius wrote:
I'm doing a house renovation, and the hot&cold water feeds to the
showers in the bathroom and ensuite are in 15mm copper. I want to
upgrade to 22mm where possible to get better flow, as the hot water is
from a cylinder with header tank.

My view is that I'd rather install 22mm everwhere where it won't be
easy to replace later, like underneath tiled floors, and behind tiled
walls. There will still be some runs in 15mm (or maybe half inch, as
some of the pipework is very old), but I might replace these
eventually.

Is this a reasonable thing to do? Are there any reasons why I
shouldn't install 22mm where possible (apart from cost, which is not a
huge factor when looking at the whole job)?


It wasn't uncommon to run 3/4" (pre-historic version of 22mm) for both
hot and cold from the tanks to quite close to the points of use.

IIRC our bath might have had 3/4" right to the taps (bath taps are
usually 3/4" threads rather than 1/2" more common on basins)

The only disadvantage is that you have to shift more water to run the
hot though - though with a tank, you can add a circulation device which
primes the pipe - rare but exists in places where the owner is big on
not wasting water.


...but small on not wasting energy :-)


The circulation pump would normally be on a timer.

Mmm so no hot water unless your demands are in sync with the timer?

Hot water any time you like. Hot water with no delay when the timer is
active.

Plus the heat lost from the water in the circulation loop
(whether the timer's on or off)?

Lag it dear liza ;-)

With which 100% efficient lagging should I lag it dear henry?

You don't... use some that is "good enough". Deduct the heat lost from
your space heating requirements, and accept that there is a price to pay
for added convenience.


--
Cheers,

John.

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

On 13/12/2018 17:49, Caecilius wrote:
I'm doing a house renovation, and the hot&cold water feeds to the
showers in the bathroom and ensuite are in 15mm copper. I want to
upgrade to 22mm where possible to get better flow, as the hot water is
from a cylinder with header tank.

My view is that I'd rather install 22mm everwhere where it won't be
easy to replace later, like underneath tiled floors, and behind tiled
walls. There will still be some runs in 15mm (or maybe half inch, as
some of the pipework is very old), but I might replace these
eventually.

Is this a reasonable thing to do? Are there any reasons why I
shouldn't install 22mm where possible (apart from cost, which is not a
huge factor when looking at the whole job)?


I'd say yes, but thinking if your hot water is really hot - your shower
mixer will then be regulating that down, and then the difference between
22mm or 15mm flow becomes not much of an issue - for the hot supply at
least.

So what flow rate do you available for the cold supply?

Cold water tank?

--
Adrian C

On 18/12/2018 21:05, Jim K.. wrote:
ARW Wrote in message:
On 14/12/2018 08:04, Jim K.. wrote:
Tim Watts Wrote in message:
On 13/12/2018 17:49, Caecilius wrote:
I'm doing a house renovation, and the hot&cold water feeds to the
showers in the bathroom and ensuite are in 15mm copper. I want to
upgrade to 22mm where possible to get better flow, as the hot water is
from a cylinder with header tank.

My view is that I'd rather install 22mm everwhere where it won't be
easy to replace later, like underneath tiled floors, and behind tiled
walls. There will still be some runs in 15mm (or maybe half inch, as
some of the pipework is very old), but I might replace these
eventually.

Is this a reasonable thing to do? Are there any reasons why I
shouldn't install 22mm where possible (apart from cost, which is not a
huge factor when looking at the whole job)?


It wasn't uncommon to run 3/4" (pre-historic version of 22mm) for both
hot and cold from the tanks to quite close to the points of use.

IIRC our bath might have had 3/4" right to the taps (bath taps are
usually 3/4" threads rather than 1/2" more common on basins)

The only disadvantage is that you have to shift more water to run the
hot though - though with a tank, you can add a circulation device which
primes the pipe - rare but exists in places where the owner is big on
not wasting water.


...but small on not wasting energy :-)


The circulation pump would normally be on a timer.

Mmm so no hot water unless your demands are in sync with the timer?

I can tell a timer when to turn on and off.

They are easier to programme than women.



--
Adam