Recently amongst many other plumbing jobs
I replaced the ball valves in the DW and FE tanks
with new part 2 floats.

Both of the tanks were very unpleasant. The 50 gal DW
tank was full of limescale/brown grit and other...
I drained it down and cleaned the tank using an ice scraper
and an old towel! Really tough job with a final bleaching
of the tank! The FE tank was full of brown rust I presume.
Didnt bother bleaching this just cleaned it.
The state of these two tanks made me think that maybe
this is something that should be done regularly, maybe
annually. Is it worth it? Thinking about legionella and
otherwise in vented systems. Am I worrying about nothing?

Matthew

On 2006-12-08 12:07:58 +0000, "Matthew" said:

Recently amongst many other plumbing jobs
I replaced the ball valves in the DW and FE tanks
with new part 2 floats.

Both of the tanks were very unpleasant. The 50 gal DW
tank was full of limescale/brown grit and other...
I drained it down and cleaned the tank using an ice scraper
and an old towel! Really tough job with a final bleaching
of the tank! The FE tank was full of brown rust I presume.
Didnt bother bleaching this just cleaned it.
The state of these two tanks made me think that maybe
this is something that should be done regularly, maybe
annually. Is it worth it? Thinking about legionella and
otherwise in vented systems. Am I worrying about nothing?

Matthew

It does make sense to clean out the DHW tank periodically and to remove
grit etc.

For the DHW feed tank, you should have a cover and ideally a water
byelaw kit to connect the overflow, vent etc.

There are millions of tanks in use in the UK and people are not going
down like ninepins with Legionella.

For the CH FE tank, sometimes there can be brownish gungy stuff arising
from corrosion inhibitor etc.
If it's rust, then perhaps you don't have inhibitor and should or there
is pumping over in the system.
There is no real need to clean jus tthe tank, but if there is rust and
sludge then the CH system ought to be cleaned as a whole and inhibitor
added.

Andy Hall wrote:
On 2006-12-08 12:07:58 +0000, "Matthew" said:

Recently amongst many other plumbing jobs
I replaced the ball valves in the DW and FE tanks
with new part 2 floats.

Both of the tanks were very unpleasant. The 50 gal DW
tank was full of limescale/brown grit and other...
I drained it down and cleaned the tank using an ice scraper
and an old towel! Really tough job with a final bleaching
of the tank! The FE tank was full of brown rust I presume.
Didnt bother bleaching this just cleaned it.
The state of these two tanks made me think that maybe
this is something that should be done regularly, maybe
annually. Is it worth it? Thinking about legionella and
otherwise in vented systems. Am I worrying about nothing?

Matthew


It does make sense to clean out the DHW tank periodically and to remove
grit etc.

For the DHW feed tank, you should have a cover and ideally a water
byelaw kit to connect the overflow, vent etc.

There are millions of tanks in use in the UK and people are not going
down like ninepins with Legionella.

For the CH FE tank, sometimes there can be brownish gungy stuff arising
from corrosion inhibitor etc.
If it's rust, then perhaps you don't have inhibitor and should or there
is pumping over in the system.
There is no real need to clean jus tthe tank, but if there is rust and
sludge then the CH system ought to be cleaned as a whole and inhibitor
added.




IIRC, Legionella has to be vapourised into steam and inhaled to make it
dangerous. Hence why most outbreaks occur through inadequate cleaning of
industrial cooling towers.

Googlebot wrote:




IIRC, Legionella has to be vapourised into steam and inhaled to make it
dangerous. Hence why most outbreaks occur through inadequate cleaning of
industrial cooling towers.

With respect you are talking ********. The water has to be turned into
droplets such as spray. That is why so many, but not all, cases of
Legionella are related to cooling towers. They create water droplets.
Google Legionella. It is endemic in all water supplies.

Steam would in fact kill legionella.

On Fri, 08 Dec 2006 04:07:58 -0800, Matthew wrote:

Recently amongst many other plumbing jobs
I replaced the ball valves in the DW and FE tanks
with new part 2 floats.

Both of the tanks were very unpleasant. The 50 gal DW
tank was full of limescale/brown grit and other...
I drained it down and cleaned the tank using an ice scraper
and an old towel! Really tough job with a final bleaching
of the tank! The FE tank was full of brown rust I presume.
Didnt bother bleaching this just cleaned it.
The state of these two tanks made me think that maybe
this is something that should be done regularly, maybe
annually. Is it worth it? Thinking about legionella and
otherwise in vented systems. Am I worrying about nothing?

Yes,
The storage cistern is nearly closed to the air if it is installed to the
Water Regs and more importantly it's cold.

If the cylinder reaches 50C from time to time then legionella is stopped.

Legionella is rare, when it does occur it is invariably as part of a
recirculation warm water cooling system exposed to the atmosphere.

--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html
Gas Fitting Standards Docs he http://www.makewrite.demon.co.uk/GasFittingStandards

"Ed Sirett" wrote in message
...
On Fri, 08 Dec 2006 04:07:58 -0800, Matthew wrote:

Recently amongst many other plumbing jobs
I replaced the ball valves in the DW and FE tanks
with new part 2 floats.

Both of the tanks were very unpleasant. The 50 gal DW
tank was full of limescale/brown grit and other...
I drained it down and cleaned the tank using an ice scraper
and an old towel! Really tough job with a final bleaching
of the tank! The FE tank was full of brown rust I presume.
Didnt bother bleaching this just cleaned it.
The state of these two tanks made me think that maybe
this is something that should be done regularly, maybe
annually. Is it worth it? Thinking about legionella and
otherwise in vented systems. Am I worrying about nothing?

Yes,
The storage cistern is nearly closed to the air if it is installed to the
Water Regs and more importantly it's cold.

If the cylinder reaches 50C from time to time then legionella is stopped.

Legionella is rare, when it does occur it is invariably as part of a
recirculation warm water cooling system exposed to the atmosphere.

While that is still accepted as a possible source of infection, it is now
considered to be a minor one. Current thinking is that the primary method of
infection, including that in the original outbreak, is aspiration of
infected water and a high percentage of domestic stored water has been found
to be infected. What makes it rare is that aspiration - inhaling water
droplets from the mouth - is not common and that there are few occasions
when stored water enters the mouth. The people at highest risk in the UK
are, therefore, those with severe coughs, such as many smokers, and people
who clean their teeth with stored water that comes from an unsealed cistern.
Infection is carried into the stored water by insects and the point of the
requirements of the Water Supply (Water Fittings) Regulations 1999, which
replaced the Water Regulations, is to exclude them from stored water.

Colin Bignell

On Sat, 9 Dec 2006 11:12:02 -0000 someone who may be "nightjar"
nightjar@insert my surname here.uk.com wrote this:-

Current thinking is that the primary method of
infection, including that in the original outbreak, is aspiration of
infected water

That has always been the thinking.

and a high percentage of domestic stored water has been found
to be infected.

Alarmist. Most water, domestic or otherwise, contains the bacteria
at low concentrations, where it poses little danger. The danger is
caused when the conditions for the things to multiply rapidly are
present, especially when vulnerable groups are exposed to aerosols.



--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

"David Hansen" wrote in message
...
On Sat, 9 Dec 2006 11:12:02 -0000 someone who may be "nightjar"
nightjar@insert my surname here.uk.com wrote this:-

Current thinking is that the primary method of
infection, including that in the original outbreak, is aspiration of
infected water

That has always been the thinking.

The difference is that the primary mechanism is no longer believed to be
normal inhalation of aerosols. Instead, it is now thought to be aspiration
of infected water present in the mouth during coughing or choking.

Colin Bignell

"nightjar .uk.com" nightjar@insert my surname here wrote in message
...

"Ed Sirett" wrote in message
...
On Fri, 08 Dec 2006 04:07:58 -0800, Matthew wrote:

Recently amongst many other plumbing jobs
I replaced the ball valves in the DW and FE tanks
with new part 2 floats.

Both of the tanks were very unpleasant. The 50 gal DW
tank was full of limescale/brown grit and other...
I drained it down and cleaned the tank using an ice scraper
and an old towel! Really tough job with a final bleaching
of the tank! The FE tank was full of brown rust I presume.
Didnt bother bleaching this just cleaned it.
The state of these two tanks made me think that maybe
this is something that should be done regularly, maybe
annually. Is it worth it? Thinking about legionella and
otherwise in vented systems. Am I worrying about nothing?

Yes,
The storage cistern is nearly closed to the air if it is installed to the
Water Regs and more importantly it's cold.

If the cylinder reaches 50C from time to time then legionella is stopped.

Legionella is rare, when it does occur it is invariably as part of a
recirculation warm water cooling system exposed to the atmosphere.

While that is still accepted as a possible source of infection, it is now
considered to be a minor one. Current thinking is that the primary method
of infection, including that in the original outbreak, is aspiration of
infected water and a high percentage of domestic stored water has been
found to be infected. What makes it rare is that aspiration - inhaling
water droplets from the mouth - is not common and that there are few
occasions when stored water enters the mouth. The people at highest risk
in the UK are, therefore, those with severe coughs, such as many smokers,
and people who clean their teeth with stored water that comes from an
unsealed cistern. Infection is carried into the stored water by insects
and the point of the requirements of the Water Supply (Water Fittings)
Regulations 1999, which replaced the Water Regulations, is to exclude them
from stored water.

Exclude what from stored water?

On Dec 9, 11:33 pm, "Doctor Drivel" wrote:


and the point of the requirements of the Water Supply (Water Fittings)
Regulations 1999, which replaced the Water Regulations, is to exclude them
from stored water.

Exclude what from stored water

He meant insects.

I don't think insects carry the bacteria into the water, the bacteria
are in the mains supply. Insect remains in the water would provide
nutrients.

In article . com,
"Matthew" writes:
I drained it down and cleaned the tank using an ice scraper
and an old towel! Really tough job with a final bleaching
of the tank!

Note that it's not a good idea to bleach a GRP tank, as
bleach makes it go brittle.

--
Andrew Gabriel

On Dec 8, 12:07 pm, "Matthew" wrote:
Thinking about legionella and
otherwise in vented systems. Am I worrying about nothing?

Matthew

No.

More info here than you can shake a stick at;

http://en.wikipedia.org/wiki/Legionnaires%27_disease

Legionella bacteria are common in the environment being found in lakes,
rivers and reservoirs in small numbers. They are in the cold water
mains supply, in small numbers.

Given favourable temperatures and a source of nutrients, they will
colonise a water system. If the water is dispersed as an aerosol
(showers, spray taps) it will be inhaled and will colonise your lungs.
A lot of people contract it and recover without realising they had it;
anyone with a compromised immune system will probably die unless
treated.

Water temperatures in the range of 20 to 45 degC favour growth; blood
temperature 37 degC ish is about ideal. Hot water should be stored at
60 degC and be 50 degC at any outlet within 60 seconds (commercial,
should be much quicker for domestic). Cold water must be kept below 20
degC at all times.

The gunge, scale, rust and biofilms in the tank are a source of
nutrients and provide a safe harbour for legionella, protecting it from
high temperatures in the HWS system, that would otherwise kill it. The
tank has got into that state because dirt can get in. Get a Bylaw 30
compliant tank (insulated, snap-on tight lid, screened overflow and
air vent, etc..) and install and insulate it carefully. They will stay
clean, save for deposits of limescale in the bottom of the tank which
can be syphoned out every year or two. The tank should provide not more
than 24 hours use, to prevent stagnation. Many water storage tanks in
UK lofts are utterly disgraceful, I wouldn't wash my car in water from
some I've seen.

The F&E tank shouldn't get hot and will get colonised by any
bacteria. My one was filled with a jelly-like slime ( possibly
psedonomas). The water shouldn't be used or become an aerosol, so
shouldn't be a hazard. I've converted to a sealed system now.

On Fri, 08 Dec 2006 12:53:59 -0800, Aidan wrote:


The gunge, scale, rust and biofilms in the tank are a source of
nutrients and provide a safe harbour for legionella, protecting it from
high temperatures in the HWS system, that would otherwise kill it. The
tank has got into that state because dirt can get in. Get a Bylaw 30
compliant tank (insulated, snap-on tight lid, screened overflow and
air vent, etc..) and install and insulate it carefully. They will stay
clean, save for deposits of limescale in the bottom of the tank which
can be syphoned out every year or two.

If you're in a hard water area you can fit a Fernox bag-in-the-tank
scale inhibitor. These are simply a mesh bag full of crystals of a
phosphate salt which prevent scale deposition. The instructions say to
hang them in the middle of the tank in free water, but most people hang
them under the ballvalve. They need to be renewed every year or so,
when the crystals have all dissolved away.

Legionella is a real risk. Most people do not realise they have
legionella as it often manifests as cold/pnuemonia type symptoms and is
put down to a virus/bacteria, from which most normal people recover.
It can however kill.

Legionella is not spread by steam but is spread by breathing in
aerosols, small water droplets which can get into the lungs. This
makes it high risk in showers, particularly showers that are not used
often, as it gets into the water stream and is broken up into the small
droplets. The person showering is stood directly below the stream and
breathes in the bacteria. Showers should be flushed at least weekly if
not used regularly and the water should be as hot as possible whilst
flushing to kill bacteria within the pipework.

Regulations in the UK for public use buildings state that the heads of
showers that can harbour these bacteria should be cleaned and
disinfected at least every 3 months.

Many hotels on the continent can be causes of legionairres disease in
early season for this reason. Showers have been left with stagnant
water in pipes until the new season at which point a holiday maker
stands underneath and has a shower in nice bacterial soup. Always run
the shower into a sealed bag and carefully place it down the drain if
you are going on holiday early season in many holiday resorts.

Whilst what you say about 50°C killing the legionella bacteria is
strictly true (it takes several minutes at this temperature) it is
often the case that the entire cylinder does not reach 50°C. Heat
rises and often there is a cold spot at the bottom of the cylinder in
which the bacteria can grow. This is particularly prevelant on large
cylinder and large calorifiers found in hospitals and the like.

The presence of biofilm/limescale and dirt as previously mentioned can
cause additional problems of protection and nutrients, thus providing a
breeding ground for legionella.

Cooling towers generate spray (and some stem if running hot) and are
also nice nutrient rich, warm and pleasant areas for legionella to
breed if left unchecked. Most cooling towers are very well managed
through regulation and company policy and actually pose little risk to
the public.

The F&E tanks should be examined for rust as other bacteria can also
cause large rust pits that if left unchcked can rapidly cause pitting
to such a degree that pin hole leaks can occurr. If rust is a large
problem it may be best to clean and dry the tank and coat the tank with
an epoxy sealer to protect the metal surfaces from the bacteria within
the water.

Bleach is fine on GRP tanks as long as it is kept to sensible levels
(50 ppm of chlorine) for short periods (1 hour). This is the standard
sterilisation proceedure used by hospitals and other public use
buildings.

John Stumbles wrote:

On Fri, 08 Dec 2006 12:53:59 -0800, Aidan wrote:


The gunge, scale, rust and biofilms in the tank are a source of
nutrients and provide a safe harbour for legionella, protecting it from
high temperatures in the HWS system, that would otherwise kill it. The
tank has got into that state because dirt can get in. Get a Bylaw 30
compliant tank (insulated, snap-on tight lid, screened overflow and
air vent, etc..) and install and insulate it carefully. They will stay
clean, save for deposits of limescale in the bottom of the tank which
can be syphoned out every year or two.

If you're in a hard water area you can fit a Fernox bag-in-the-tank
scale inhibitor. These are simply a mesh bag full of crystals of a
phosphate salt which prevent scale deposition. The instructions say to
hang them in the middle of the tank in free water, but most people hang
them under the ballvalve. They need to be renewed every year or so,
when the crystals have all dissolved away.

"Blogz" wrote in message
oups.com...
Legionella is a real risk. Most people do not realise they have
legionella as it often manifests as cold/pnuemonia type symptoms and is
put down to a virus/bacteria, from which most normal people recover.
It can however kill.

Legionella is not spread by steam but is spread by breathing in
aerosols, small water droplets which can get into the lungs....

Aspiration of infected water in the mouth is now considered to be the
primary route of infection, although, obviously, that does not make showers
any less of a risk, as they can be the source of that water.

Colin Bignell

In article .com
, Blogz writes
Legionella is a real risk. Most people do not realise they have
legionella as it often manifests as cold/pnuemonia type symptoms and is
put down to a virus/bacteria, from which most normal people recover.
It can however kill.

Any idea if there is a low cost way of testing for high levels of Legionella or
other risky water borne bacteria? I'm thinking of the scenario where there is
an adult resident that frequently succumbs to cold and flu like symptoms
and it would be nice to narrow down possible causes. I know it would be
straightforward to disinfect the water system but it would be nice to track
down causes rather than hitting and hoping.

In case it is of interest, the scenario is in a 4 storey multiple occupancy
building with loft header tanks. Hot water vent pipes go all the way to the
top so there is great scope for stagnant partially heated water in these
pipes. Many residents have converted to combis so fewer are using the
header tank water, leading to plenty of stagnant cold water too.
--
fred
Plusnet - I hope you like vanilla

On Dec 9, 2:05 pm, fred wrote:
Any idea if there is a low cost way of testing for high levels of Legionella or
other risky water borne bacteria? I'm thinking of the scenario where there is
an adult resident that frequently succumbs to cold and flu like symptoms
and it would be nice to narrow down possible causes. I know it would be
straightforward to disinfect the water system but it would be nice to track
down causes rather than hitting and hoping.

No.

" Analysis of water for legionella should be carried out by a UKAS
accredited laboratory which takes part in the PHLS Water Microbiology
External Quality assessment Scheme for the isolation of Legionella from
Water. The interpretatioin of any results should be carried out by an
experienced microbiologist."
( from 'Legionnaires' Disease, The control of legionella bacteria in
water systems', HSE).

A blood test would confirm whether the person has had the disease, or
whatever else they may be suffering from.See GP.

The buildings' water systems and control regimes should be regularly
inspected and monitored. If the hot isn't at 50 degC at any tap within
1 minute, or if the cold gets much above 20 degC, you have a problem.

"Blogz" wrote in message
oups.com...
Legionella is a real risk. Most people do not realise they have
legionella as it often manifests as cold/pnuemonia type symptoms and is
put down to a virus/bacteria, from which most normal people recover.
It can however kill.

Legionella is not spread by steam but is spread by breathing in
aerosols, small water droplets which can get into the lungs. This
makes it high risk in showers, particularly showers that are not used
often, as it gets into the water stream and is broken up into the small
droplets. The person showering is stood directly below the stream and
breathes in the bacteria. Showers should be flushed at least weekly if
not used regularly and the water should be as hot as possible whilst
flushing to kill bacteria within the pipework.

Regulations in the UK for public use buildings state that the heads of
showers that can harbour these bacteria should be cleaned and
disinfected at least every 3 months.

Many hotels on the continent can be causes of legionairres disease in
early season for this reason. Showers have been left with stagnant
water in pipes until the new season at which point a holiday maker
stands underneath and has a shower in nice bacterial soup. Always run
the shower into a sealed bag and carefully place it down the drain if
you are going on holiday early season in many holiday resorts.

Whilst what you say about 50°C killing the legionella bacteria is
strictly true (it takes several minutes at this temperature) it is
often the case that the entire cylinder does not reach 50°C. Heat
rises and often there is a cold spot at the bottom of the cylinder in
which the bacteria can grow. This is particularly prevelant on large
cylinder and large calorifiers found in hospitals and the like.


That is why cylinders with domes at the bottom preventing a dead spot at the
bottom of the cylinder are superior. Gledhill make these.


Cooling towers generate spray (and some stem if running hot) and are
also nice nutrient rich, warm and pleasant areas for legionella to
breed if left unchecked.


Cooling towers have to be a sealed circulation system these days.

On Dec 10, 10:52 am, "Doctor Drivel" wrote:

Cooling towers have to be a sealed circulation system these days.

No. They cannot be "sealed circulation systems". The cooling is
achgieved by evaporating water to the atmosphere and so they are
inherently prone to contamination from the environment.

http://en.wikipedia.org/wiki/Cooling_towers

Blogz wrote:
Legionella is a real risk. Most people do not realise they have
legionella as it often manifests as cold/pnuemonia type symptoms and is
put down to a virus/bacteria, from which most normal people recover.
It can however kill.

Legionella is not spread by steam but is spread by breathing in
aerosols, small water droplets which can get into the lungs. This
makes it high risk in showers, particularly showers that are not used
often, as it gets into the water stream and is broken up into the small
droplets. The person showering is stood directly below the stream and
breathes in the bacteria. Showers should be flushed at least weekly if
not used regularly and the water should be as hot as possible whilst
flushing to kill bacteria within the pipework.

Regulations in the UK for public use buildings state that the heads of
showers that can harbour these bacteria should be cleaned and
disinfected at least every 3 months.

Many hotels on the continent can be causes of legionairres disease in
early season for this reason. Showers have been left with stagnant
water in pipes until the new season at which point a holiday maker
stands underneath and has a shower in nice bacterial soup. Always run
the shower into a sealed bag and carefully place it down the drain if
you are going on holiday early season in many holiday resorts.

Whilst what you say about 50°C killing the legionella bacteria is
strictly true (it takes several minutes at this temperature) it is
often the case that the entire cylinder does not reach 50°C. Heat
rises and often there is a cold spot at the bottom of the cylinder in
which the bacteria can grow. This is particularly prevelant on large
cylinder and large calorifiers found in hospitals and the like.

The presence of biofilm/limescale and dirt as previously mentioned can
cause additional problems of protection and nutrients, thus providing a
breeding ground for legionella.

Cooling towers generate spray (and some stem if running hot) and are
also nice nutrient rich, warm and pleasant areas for legionella to
breed if left unchecked. Most cooling towers are very well managed
through regulation and company policy and actually pose little risk to
the public.

The F&E tanks should be examined for rust as other bacteria can also
cause large rust pits that if left unchcked can rapidly cause pitting
to such a degree that pin hole leaks can occurr. If rust is a large
problem it may be best to clean and dry the tank and coat the tank with
an epoxy sealer to protect the metal surfaces from the bacteria within
the water.

Bleach is fine on GRP tanks as long as it is kept to sensible levels
(50 ppm of chlorine) for short periods (1 hour). This is the standard
sterilisation proceedure used by hospitals and other public use
buildings.

At last! Someone who knows what they are talking about when it comes to
Legionella in domestic circumstances. I started a thread some time ago
regarding the dangers of imported, low quality, EPDM cored Flexible tap
hoses that have been proven by Dr Tom Makin of Liverpool University to
harbour Legionella growing on biofilms on the EPDM rubber. I was well
flamed for my thread.

On Dec 11, 9:27 am, "Merryterry" wrote:
I started a thread some time ago
regarding the dangers of imported, low quality, EPDM cored Flexible tap
hoses that have been proven by Dr Tom Makin of Liverpool University to
harbour Legionella growing on biofilms on the EPDM rubber. I was well
flamed for my thread.

My recollection is that you had some commercial interest in the WRAS
approved flexible hoses. Your post came across as yet more spam, rather
than as altruistic advice and spam does tend to get flambéed around
here.

On Dec 8, 12:07 pm, "Matthew" wrote:
Thinking about legionella and
otherwise in vented systems. Am I worrying about nothing?

Matthew

No.

More info here than you can shake a stick at;

http://en.wikipedia.org/wiki/Legionnaires%27_disease

Legionella bacteria are common in the environment being found in lakes,
rivers and reservoirs in small numbers. They are in the cold water
mains supply, in small numbers.

Given favourable temperatures and a source of nutrients, they will
colonise a water system. If the water is dispersed as an aerosol
(showers, spray taps) it will be inhaled and will colonise your lungs.
A lot of people contract it and recover without realising they had it;
anyone with a compromised immune system will probably die unless
treated.

Water temperatures in the range of 20 to 45 degC favour growth; blood
temperature 37 degC ish is about ideal. Hot water should be stored at
60 degC and be 50 degC at any outlet within 60 seconds (commercial,
should be much quicker for domestic). Cold water must be kept below 20
degC at all times.

The gunge, scale, rust and biofilms in the tank are a source of
nutrients and provide a safe harbour for legionella, protecting it from
high temperatures in the HWS system, that would otherwise kill it. The
tank has got into that state because dirt can get in. Get a Bylaw 30
compliant tank (insulated, snap-on tight lid, screened overflow and
air vent, etc..) and install and insulate it carefully. They will stay
clean, save for deposits of limescale in the bottom of the tank which
can be syphoned out every year or two. The tank should provide not more
than 24 hours use, to prevent stagnation. Many water storage tanks in
UK lofts are utterly disgraceful, I wouldn't wash my car in water from
some I've seen.

The F&E tank shouldn't get hot and will get colonised by any
bacteria. My one was filled with a jelly-like slime ( possibly
psedonomas). The water shouldn't be used or become an aerosol, so
shouldn't be a hazard. I've converted to a sealed system now.

"Matthew" wrote in message
ups.com...
... Thinking about legionella and
otherwise in vented systems. Am I worrying about nothing?

As others have said, there is a definite risk with open cisterns. Your
domestic cold water supply cistern should have a tight-fitting, insect and
light proof lid and be fitted with a Water Bye-Law kit. Although the Water
Bye-Laws were superceded in 1999, the kits are still known by that name and
will include an insect-proof screen for the warning (overflow) pipe, with a
dip pipe that will take the end of the pipe just below the full water level,
an insect-proof air vent, to allow air in and out as the water level changes
and a tight-fitting seal for the hot water cylinder vent pipe.

Colin Bignell

On Sat, 9 Dec 2006 11:19:53 -0000, "nightjar" nightjar@insert my surname
here.uk.com wrote:


Your
domestic cold water supply cistern should have a tight-fitting, insect and
light proof lid and be fitted with a Water Bye-Law kit. Although the Water
Bye-Laws were superceded in 1999, the kits are still known by that name and
will include an insect-proof screen for the warning (overflow) pipe, with a
dip pipe that will take the end of the pipe just below the full water level,
an insect-proof air vent, to allow air in and out as the water level changes
and a tight-fitting seal for the hot water cylinder vent pipe.

Just what I would like for my old tank - no joy with google though - any
pointers to supplier?

Geo

On Sun, 10 Dec 2006 17:42:58 GMT someone who may be Geo
wrote this:-

Your
domestic cold water supply cistern should have a tight-fitting, insect and
light proof lid and be fitted with a Water Bye-Law kit. Although the Water
Bye-Laws were superceded in 1999, the kits are still known by that name and
will include an insect-proof screen for the warning (overflow) pipe, with a
dip pipe that will take the end of the pipe just below the full water level,
an insect-proof air vent, to allow air in and out as the water level changes
and a tight-fitting seal for the hot water cylinder vent pipe.

Just what I would like for my old tank - no joy with google though - any
pointers to supplier?


Any of them, including large orange tin sheds.



--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

In article ,
Geo writes:
On Sat, 9 Dec 2006 11:19:53 -0000, "nightjar" nightjar@insert my surname
here.uk.com wrote:


Your
domestic cold water supply cistern should have a tight-fitting, insect and
light proof lid and be fitted with a Water Bye-Law kit. Although the Water
Bye-Laws were superceded in 1999, the kits are still known by that name and
will include an insect-proof screen for the warning (overflow) pipe, with a
dip pipe that will take the end of the pipe just below the full water level,
an insect-proof air vent, to allow air in and out as the water level changes
and a tight-fitting seal for the hot water cylinder vent pipe.

Just what I would like for my old tank - no joy with google though - any
pointers to supplier?

You'll probably have difficulty retofitting a new lid to an old tank.
All the other bits are available from every plumber's merchant.

--
Andrew Gabriel

"Geo" wrote in message
...
On Sat, 9 Dec 2006 11:19:53 -0000, "nightjar" nightjar@insert my surname
here.uk.com wrote:


Your
domestic cold water supply cistern should have a tight-fitting, insect and
light proof lid and be fitted with a Water Bye-Law kit. Although the Water
Bye-Laws were superceded in 1999, the kits are still known by that name
and
will include an insect-proof screen for the warning (overflow) pipe, with
a
dip pipe that will take the end of the pipe just below the full water
level,
an insect-proof air vent, to allow air in and out as the water level
changes
and a tight-fitting seal for the hot water cylinder vent pipe.

Just what I would like for my old tank - no joy with google though - any
pointers to supplier?

Any plumbers' merchant. In theory, the overflow ought to be 1" these days,
but almost all are still 3/4" and the Water Bye-Law kits are all made to fit
that.

Colin Bignell