Not quite a DIY question but this seemed like the right group of
people to ask.

So in my loft there is an enormous water tank. I'd guess, 200 litres?
500? Its big.

(It is not the radiator tank AFAIK that is a smaller one)

It seems that this is a reservoir for tap water. The bathroom is
upstairs (first floor). The tub has MUCH higher pressure than the
sink, so I assume the former is mains and the latter is the tank. FYI
the garden hose produced reasonable pressure at about the same height
when I was washing moss off the roof of the extension hence my
assumption.

Anyway, the question is, what is this huge tank for? If mains pressure
is good enough... why bother having it?

And is it sanitary? I suspect I'm missing out on some important
homeowner duties in terms of caring for this thing.

Thanks,
David

wrote:

Anyway, the question is, what is this huge tank for? If mains pressure
is good enough... why bother having it?

Traditional vented hot water systems use a loft tank to feed the hot
water cylinder. So the water in that tank provides the head for your hot
water in the bathroom and kitchen.

In order to get similar flow rates from hot and cold taps, and in order
for shower mixers to function correctly, the bathroom cold taps and
shower are usually also fed from this tank.


And is it sanitary? I suspect I'm missing out on some important
homeowner duties in terms of caring for this thing.

It should have a well fitted lid, and the water in it should be clean.


--
Grunff
Super-bright LED torches
http://www.shinyshack.com/product.php?prid=211015

On 2007-07-04 23:56:35 +0100, said:

Not quite a DIY question but this seemed like the right group of
people to ask.

So in my loft there is an enormous water tank. I'd guess, 200 litres?
500? Its big.

200 would be fairly large but not impossible.


(It is not the radiator tank AFAIK that is a smaller one)

It seems that this is a reservoir for tap water. The bathroom is
upstairs (first floor). The tub has MUCH higher pressure than the
sink, so I assume the former is mains and the latter is the tank. FYI
the garden hose produced reasonable pressure at about the same height
when I was washing moss off the roof of the extension hence my
assumption.

It's the cold supply for the hot water system.



Anyway, the question is, what is this huge tank for? If mains pressure
is good enough... why bother having it?

Because the mains may not be able to deliver the flow rate.


And is it sanitary?

Yes, provided that it has a cover and a water byelaws kit. That
consists of various screens and bits for the various pipes to keep
creepy crawlies out.



I suspect I'm missing out on some important
homeowner duties in terms of caring for this thing.

Thanks,
David

wrote in message
oups.com...

Anyway, the question is, what is this huge tank for? If mains pressure
is good enough... why bother having it?

I would presume (without looking at it) that it is the feed tank for your
immersion cylinder which you will probably find in an upstairs cupboard,
although they can be downstairs in certain installations. To check look for
an immersion heater cylinder or sit next to the huge tank and ask somebody
to turn a hot tap on and you should hear it refilling. Unless of course you
now have a combi boiler and the lazy ar**d plumber couldn't be bothered to
empty and remove this tank!!

HTH

John

On Thu, 5 Jul 2007 00:27:01 +0100, "John"
mused:


wrote in message
roups.com...

Anyway, the question is, what is this huge tank for? If mains pressure
is good enough... why bother having it?

I would presume (without looking at it) that it is the feed tank for your
immersion cylinder which you will probably find in an upstairs cupboard,
although they can be downstairs in certain installations. To check look for
an immersion heater cylinder or sit next to the huge tank and ask somebody
to turn a hot tap on and you should hear it refilling. Unless of course you
now have a combi boiler and the lazy ar**d plumber couldn't be bothered to
empty and remove this tank!!

It's not an immersion tank\cylinder, it's a hot water cylinder.
--
Regards,
Stuart.

wrote in message
oups.com...
Not quite a DIY question but this seemed like the right group of
people to ask.

So in my loft there is an enormous water tank. I'd guess, 200 litres?
500? Its big.

(It is not the radiator tank AFAIK that is a smaller one)

It seems that this is a reservoir for tap water. The bathroom is
upstairs (first floor). The tub has MUCH higher pressure than the
sink, so I assume the former is mains and the latter is the tank.

If you find the stopcock supplying mains water to your house and turn it off
then any tap that still works is supplied from the tank.

FYI
the garden hose produced reasonable pressure at about the same height
when I was washing moss off the roof of the extension hence my
assumption.

Anyway, the question is, what is this huge tank for?

It's called a "spider tank". Its primary purpose is to supply the head for
the hot water cylinder and the non-potable cold water supplies in the
bathrooms. Its secondary purpose is to give spiders in your loft somewhere
to live, spin their webs and eventually grow huge, die, fall into it and
decompose. From time you therefore run a bath and find enormous chitinous
chunks of legs and carapaces swirling about in the water. Doesn't bother me
much but puts the fear of god into female guests

Of course you could put a lid on it I suppose but that would spoil the fun.

Does anyone else keep a plastic sieve hanging on a nail by their bath or is
it just me? OK, just me then. Thought so.
--
Dave Baker
Resistance is useless (The Daleks)
Resistance is futile (The Borg)
Resistance is volts divided by amps (Georg Ohm)

wrote:

To add to what others have said...

Anyway, the question is, what is this huge tank for? If mains pressure
is good enough... why bother having it?

Note that not all homes have them; mine doesn't, for example. It's a
very 'British' thing. I think there's a move away from fitting them
these days.

And is it sanitary? I suspect I'm missing out on some important
homeowner duties in terms of caring for this thing.

You'll find that that it won't be connected to the kitchen sink (and
possibly others?) - if so that's the only tap which should be used for
drinking water.

David

"Lobster" wrote in message
...
wrote:

To add to what others have said...

Anyway, the question is, what is this huge tank for? If mains pressure
is good enough... why bother having it?

Note that not all homes have them; mine doesn't, for example. It's a very
'British' thing. I think there's a move away from fitting them these
days.


Two comments; - the 'British thing' about having a tank of water in the loft
relieves the requirement for the main to 'instantly' supply the water used
.... generally smoothing out the flow on the main- the tank-in-th-loft acts
as a capacitor - AND if the main is subject to 'problems' such as a burst
(bomb or accidental) then there's a supply of in-house water to flush the
toilets etc. [This used to be called 'Civil Defence' but it's nowadays
called 'Resilience Preparedness']


And is it sanitary? I suspect I'm missing out on some important
homeowner duties in terms of caring for this thing.

You'll find that that it won't be connected to the kitchen sink (and
possibly others?) - if so that's the only tap which should be used for
drinking water.

David

--

Brian

As others have said, it's almost certainly a header tank for your hot
water system.
From the way you describe it, it's not very sanitary.
Modern requirements are for a tank to have a close fitting lid, insect
traps on any breathers and the volume should not exceed 24 hours
normal usage.
What is it made of and what's the condition of the tank and the water?
If there's rubbish/rust/scale in there, you should do something about
it.
Google Legionella L8 for more info. L8 is the HSE Approved Code of
Practice and, although it doesn't legally apply to domestic houses, is
a good basis for your decisions.

John

Brian Sharrock wrote:

"Lobster" wrote in message
...
wrote:

To add to what others have said...

Anyway, the question is, what is this huge tank for? If mains pressure
is good enough... why bother having it?

Note that not all homes have them; mine doesn't, for example. It's a very
'British' thing. I think there's a move away from fitting them these
days.


Two comments; - the 'British thing' about having a tank of water in the loft
relieves the requirement for the main to 'instantly' supply the water used
... generally smoothing out the flow on the main- the tank-in-th-loft acts
as a capacitor - AND if the main is subject to 'problems' such as a burst
(bomb or accidental) then there's a supply of in-house water to flush the
toilets etc. [This used to be called 'Civil Defence' but it's nowadays
called 'Resilience Preparedness']

I discovered a couple of years ago when the lockshield failed to work
that our toilet is mains fed*. Which meant I could work on the sistern
and them who wished to use the toilet could flush it via a bucket filled
from the bath, which is on the header tank. Worked long enough for me to
learn compression fitted plumbing ;-)

*After I had bought one of them rubber bung on a string kits for
shutting off the header, assuming the toilet to be on it.

Peter
--
Add my middle initial to email me. It has become attached to a country
www.the-brights.net

In article .com,
wrote:
Anyway, the question is, what is this huge tank for? If mains pressure
is good enough... why bother having it?

Depending on the water system design, it might supply all the water to the
house with the exception of the kitchen cold water tap which is always
mains.

The problem with mains everywhere can be not the pressure but the maximum
flow. So that flushing a toilet might effect the operation of a shower,
etc. With a well designed storage system this doesn't happen.

A storage system relies on evening out demand on the mains input - it
obviously can't supply any more water over a period than the mains can
supply. But is capable of allowing much greater peak demands, and
replenishing itself at quiet periods.

These days most would want mains cold water where it is likely to be used
as drinking water etc. So to bathroom basins etc as well as the kitchen.
Although stored cold water will be perfectly safe to drink if the storage
tank complies to regulations.

--
*A clear conscience is usually the sign of a bad memory *

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

In article .com,
John wrote:
What is it made of and what's the condition of the tank and the water?
If there's rubbish/rust/scale in there, you should do something about
it.
Google Legionella L8 for more info. L8 is the HSE Approved Code of
Practice and, although it doesn't legally apply to domestic houses, is
a good basis for your decisions.

Are there any documented cases of Legionella causing problems in a
domestic storage system?

--
*It's a thankless job, but I've got a lot of Karma to burn off

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

Are there any documented cases of Legionella causing problems in a
domestic storage system?

The easy answer is no but as domestic properties are not investigated,
no one knows the extent of the problem.
There are certainly cases where people have contracted Legionaires
disease from showers.
http://news.bbc.co.uk/1/hi/england/somerset/5256926.stm

Legionaires disease is a respiratory infection similar to Pneumonia.
It's contracted by inhaling a contaminated water aerosol. The most
likely sources are cooling towers and spa pools but there are many
others. Basically, if you keep water for longer than a week (less if
it's warmer) Legionella bacteria will almost certainly develop. If
that water is then sprayed, an aerosol is produced which can cause
Legionaires disease.
Most UK cases arrise after holidays, particularly foreign ones. In
warmer climates, Legionella is more difficult to control and, with an
incubation period of 7 - 10 days, any illness could occur long after
the holiday. Coincedentally, during the holiday, the domestic water
system is unused. Loft tanks etc get warm and the bacteria grows. Run
a tap, flush a toilet, spray water on the garden or have a shower and
an aerosol is produced. By the time any symptoms develop, the house
sytem has been flushed many times making detection difficult.
There's lots of information out there if you're bored.

John

In article . com,
John wrote:
Are there any documented cases of Legionella causing problems in a
domestic storage system?

The easy answer is no but as domestic properties are not investigated,
no one knows the extent of the problem.
There are certainly cases where people have contracted Legionaires
disease from showers.
http://news.bbc.co.uk/1/hi/england/somerset/5256926.stm

Yes - but that's in a hospital where all sorts of other reasons could have
led to contamination of a water supply.

I'm more concerned with a domestic storage system. Many seem to think them
unhygienic - and I wondered if there was any substance to this rather
than purely a 'gut' feeling. After all, they were the norm once in many
areas - and with open topped tanks.

--
*If at first you don't succeed, destroy all evidence that you tried *

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

In article ,
Dave Plowman (News) wrote:

I'm more concerned with a domestic storage system. Many seem to
think them unhygienic - and I wondered if there was any
substance to this rather than purely a 'gut' feeling. After all,
they were the norm once in many areas - and with open topped
tanks.

When we lived in Cheltenham the next door had two
young children. Their hot water supply had always
been a little erratic, but when she was filling the
bath one evening for the two girls the decomposed
remains of a large bird came through the tap.

The tank in the loft had no lid and they think that
a blackbird or starling had fallen in, drowned,
rotted, and eventually bits of it came through the
pipes.

She still has the heeby-jeebies about exactly what
they were bathing in all those months before.

--
Tony Williams.

On Thu, 05 Jul 2007 14:30:42 +0100, "Dave Plowman (News)"
wrote:

I'm more concerned with a domestic storage system. Many seem to think them
unhygienic - and I wondered if there was any substance to this rather
than purely a 'gut' feeling. After all, they were the norm once in many
areas - and with open topped tanks.

Many years ago I did read an article on this and the tanks were a
breeding ground for bacteria, not necessarily harmful ones. Much
greater emphasis was put on vermin dying in them.

The bacteria angle was because the tanks tended to be galvanised and
right over the airing cupboard for the support of the four cupboard
walls, and thus warmer than expected for a roof situation. Also the
tanks tended to be large, having to supply all internal water, except
the kitchen tap, and thus only partially emptied with daily use.

The tanks were run from solid fuel back boilers and subject to the
overheating pipe emptying into them for additional hazard, there being
no dedicated CH header tank.

As another poster said rules were tightnened with close lids and
capacity only to supply a daily need to ensure regular water changes.

We sold a house at Xmas with exactly this situation and I always
shuddered when I cleaned my teeth there, remembering where the hot and
cold water to the basin was coming from.

I'm more concerned with a domestic storage system. Many seem to think them
unhygienic - and I wondered if there was any substance to this rather
than purely a 'gut' feeling. After all, they were the norm once in many
areas - and with open topped tanks.

As I said, since domestic systems are rarely checked, information is
very sparse.
However, we carry out routine water tests at work and recently found
Legionella in 3 of our hot water cylinders so it's more than just a
theory. Our systems are larger than domestic but of a similar design.

Open topped tanks are essentially unhygenic as others have said. The
longer that the water is in there, the worse it gets. That's why tanks
need to be as small as possible to reduce the residesnce time. They
should also be as clean as possible so that the water (and bugs) can't
hide and stay for long periods. Tanks should also have the inlet and
outlet at oposite ends to prevent stagnation. All very simple things
that can make a water sytem much safer.

John

Tony Williams wrote:
In article ,
Dave Plowman (News) wrote:

The tank in the loft had no lid and they think that
a blackbird or starling had fallen in, drowned,
rotted, and eventually bits of it came through the
pipes.

She still has the heeby-jeebies about exactly what
they were bathing in all those months before.

Mm, nice... hope it didn't feed the bathroom basin tap too!

David

"John" wrote in message
ups.com...
Are there any documented cases of Legionella causing problems in a
domestic storage system?

The easy answer is no but as domestic properties are not investigated,
no one knows the extent of the problem.
There are certainly cases where people have contracted Legionaires
disease from showers.
http://news.bbc.co.uk/1/hi/england/somerset/5256926.stm

Legionaires disease is a respiratory infection similar to Pneumonia.
It's contracted by inhaling a contaminated water aerosol. The most
likely sources are cooling towers and spa pools but there are many
others. Basically, if you keep water for longer than a week (less if
it's warmer) Legionella bacteria will almost certainly develop. If
that water is then sprayed, an aerosol is produced which can cause
Legionaires disease.

Current thinking is that contaminated water in the mouth aspirated during
choking or coughing is the primary method of infection and possibly was even
the way the outbreak that gave the disease its name happened. That means
that any stored water system presents a potential risk and is a good reason
for having the handbasin in the bathroom mains fed, to reduce the risk to
anyone cleaning their teeth there. Mind you, I make and sell water byelaw
kits, mostly for really big systems (an 8" overflow pipe is the largest so
far), and my loft cistern is still unprotected - the cobbler's children
syndrome.

Colin Bignell

In article ,
Lobster wrote:

Tony Williams wrote:
She still has the heeby-jeebies about exactly what
they were bathing in all those months before.

Mm, nice... hope it didn't feed the bathroom basin tap too!

So do I, but knowing that builder..........

--
Tony Williams.

Aarrg, you just rekindled a supressed memory from my student days in a
shared old terrace house. For weeks there had been a growing nasty
odour around the bathroom, particularly when having a bath. We
supsected the drains but I had a feeling it was the water itself. The
landlord insisted repeatedly he could find nothing. One day we
returned home to find a soggy decomposed bird lying on the slabs
outside the back door. This roused my suspicion and I challenged the
landlord. To start with he was cagey, then the slimeball admitted he
had found it in the tank and must have "overlooked" it when he
previously checked. Why he chose to dump the carcass like that is
beyond me. "heeby jeebies" pretty much describes the feeling we had
wondering what we had been bathing in, drinking and brushing teeth in
for weeks. I don't think the bathroom tap was mains fed and I do know
one flatmate had a habit of filling the kettle from the hot kitchen
tap. The fact it would be boiled didn't make me feel any better. Yuk.

AA

Tony Williams wrote:

When we lived in Cheltenham the next door had two
young children. Their hot water supply had always
been a little erratic, but when she was filling the
bath one evening for the two girls the decomposed
remains of a large bird came through the tap.

The tank in the loft had no lid and they think that
a blackbird or starling had fallen in, drowned,
rotted, and eventually bits of it came through the
pipes.

She still has the heeby-jeebies about exactly what
they were bathing in all those months before.

"Lurch" wrote in message
...
On Thu, 5 Jul 2007 00:27:01 +0100, "John"
mused:


wrote in message
groups.com...

Anyway, the question is, what is this huge tank for? If mains pressure
is good enough... why bother having it?

I would presume (without looking at it) that it is the feed tank for your
immersion cylinder which you will probably find in an upstairs cupboard,
although they can be downstairs in certain installations. To check look
for
an immersion heater cylinder or sit next to the huge tank and ask somebody
to turn a hot tap on and you should hear it refilling. Unless of course
you
now have a combi boiler and the lazy ar**d plumber couldn't be bothered to
empty and remove this tank!!

It's not an immersion tank\cylinder, it's a hot water cylinder.

Thanks for the lesson!! As the OP is a new home owner he would, more than
likely, have heard of the term "immersion heater" but may not know what to
look for if searching for a "hot water cylinder" and may have had to come
back to ask again. Also if he doesn't have gas and doesn't turn the
"immersion" on it would in fact be a COLD water cylinder. Now go away and
play with the mains!

John

Its been a bit but I just wanted to say thanks to everyone who replied
- answered my question marvelously.

Thanks again,
David