Tim Downie wrote:

Oh, righto, I thought it was a sealed system with a substandard
installation.

Wouldn't have had a header tank in that case. ;-)

I thought the header tank was simply left in place from an older
installation or for another system in the same house. I've got a sealed
system for central heating and hot water. There are still two header
tanks in the loft above one bedroom and one of those is still in use, as
the header tank for the woodburner with a back boiler.

On Thu, 04 Dec 2008 16:17:06 +0000, Tim S wrote:

Is it possible to buy non plastic header tanks?

I looked, but couldn;t find anything...

Yes. Drayton Tanks do glass fibre ones, including ones rated at 100C.
They cost an arm and a leg tho' You can probably still get galvanised
steel ones if you look hard enough.

Bill Taylor coughed up some electrons that declared:

Drayton Tanks

Ah yes - 100+ quid - I see your point(!)

:O

Bill Taylor wrote:

On Thu, 04 Dec 2008 16:17:06 +0000, Tim S wrote:

Is it possible to buy non plastic header tanks?

Yes. Drayton Tanks do glass fibre ones,

Errm, GRP *is* plastic.

"Tim Downie" wrote in message
...

A car has far more killing potential but it requires no mandatory testing
until it is at least 3 years old.

However if it is faulty you will be done for driving it even if its a week
old.

"Steve Firth" wrote in message
.. .
Bill Taylor wrote:

On Thu, 04 Dec 2008 16:17:06 +0000, Tim S wrote:

Is it possible to buy non plastic header tanks?

Yes. Drayton Tanks do glass fibre ones,

Errm, GRP *is* plastic.


Glass fibre
Reinforced
Polyurethane

On Thu, 4 Dec 2008 19:32:35 +0000, (Steve Firth)
wrote:

Bill Taylor wrote:

On Thu, 04 Dec 2008 16:17:06 +0000, Tim S wrote:

Is it possible to buy non plastic header tanks?

Yes. Drayton Tanks do glass fibre ones,

Errm, GRP *is* plastic.

So is galvanised steel.

"Tim Downie" wrote in message
...

This one wants to see bodies first before the are outlawed. There is no
need for unvented cylinders when vented heat banks are around. Zero risk
is what you aim for.

Zero risk is a goal of fools.

Only a complete fool would write that.

From the moment of conception until the day you die your life is filled
with risk. Sensible risk reduction is what you aim for.

Yes, zero if it is obtainable.

A car has far more killing potential but it requires no mandatory testing
until it is at least 3 years old.

Which is totally irrelevant to domestic DHW production and storage.

Boy, you are confused.

"Tim S" wrote in message
...
Doctor Drivel coughed up some electrons that declared:


"Tim S" wrote in message
...
Doctor Drivel coughed up some electrons that declared:

It doesn't matter what the kW was. Using 1kW can cause a boom, it takes
longer.

Not if the cylinder can lose 1kW by radiation/convection,

You really don't know.

Neither

You really have clue. Don't ever touch any plumber or gas equipment. Get
real people to do that.

"Andy Dingley" wrote in message
...
On 4 Dec, 14:05, Tim S wrote:

Not if the cylinder can lose 1kW by radiation/convection,

In which case you need to insulate it! (for practical domestic values
of area, volume and max. temp)

Don't confuse him any further!!!

"Tim S" wrote in message
...
Andy Dingley coughed up some electrons that declared:

On 4 Dec, 14:05, Tim S wrote:

Not if the cylinder can lose 1kW by radiation/convection,

In which case you need to insulate it! (for practical domestic values
of area, volume and max. temp)

Yeah I know

You don't, you made that up.

"Tim Downie" wrote in message
...
Doctor Drivel wrote:
"YAPH" wrote in message
...

Having the main thermostat and the safety cutout both fail to danger
is extremely unlikely and I'm sure the probability of any given
unvented installation being subjected to these conditions is very,
very remote. However as the number of unvented installations - and
installations that aren't safety checked periodically - increases,
so the probability of *some* of those installations failing to danger
increases. And the
*consequence* of such failure is Not Good (tm).

Those who vehemently defend unvented cylinders over near zero risk
DHW only vented heat banks,

But it's not zero is it? You can't ignore the deaths from vented cylinder
systems

You really have no clue how they work. Get yourself a how things work book.

Doctor Drivel coughed up some electrons that declared:


You really have clue.

You must be having a lucid moment at last.

Don't ever touch any plumber

I wasn't going to; I'll leave that to senile old perverts like yourself...

"Tim S" wrote in message
...

Don't ever touch any plumber

I wasn't going to;

You were.

On Thu, 04 Dec 2008 13:33:44 +0000, Doctor Drivel wrote:

This is a good sign, the therapy is working.

What sort are you having, by the way?


;-)



--
John Stumbles -- http://yaph.co.uk

Many hands make light work. Too many cooks spoil the broth.

On Thu, 04 Dec 2008 16:51:44 +0000, John Rumm wrote:

I was thinking of two - one where the plastic header tank got back
filled with hot and failed, and another where a cylinder ruptured and
dumped hot water on sleeping people below.

I thought they were both storage tank collapse incidents. What caused the
cylinder to rupture, do you know? Sounds almost as if it had gone
unvented.



--
John Stumbles -- http://yaph.co.uk

I am neither for nor against apathy

YAPH wrote:
On Thu, 04 Dec 2008 16:51:44 +0000, John Rumm wrote:

I was thinking of two - one where the plastic header tank got back
filled with hot and failed, and another where a cylinder ruptured and
dumped hot water on sleeping people below.

I thought they were both storage tank collapse incidents. What caused the
cylinder to rupture, do you know? Sounds almost as if it had gone
unvented.

The recentish one certainly was. I am not sure the older report actually
contained specific info - only "burst hot water cylinder".

Undersized vent scaling up, or inappropriate fitting of a gate valve in
the wrong place would seem like obvious culprits though.

--
Cheers,

John.

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

BigWallop wrote:


Errm, GRP *is* plastic.


Glass fibre
Reinforced
Polyurethane

No.

On Thu, 04 Dec 2008 10:41:15 GMT, YAPH wrote:

On Wed, 03 Dec 2008 17:36:58 +0000, John Rumm wrote:

Even if that were true (which I doubt), a large proportion are unlikely
to ever be heated via the immersion, given the added cost compared to
doing it with the boiler.

I come across a number of places where I find the immersion heater
switched on despite the central heating system working. To many
householders it's just a switch in the airing cupboard that does something
magical and if it happens to be switched on and everything works, they
leave it that way.

My God! I'd hate to see their leccy bill. My immersion was left on by
a "guest" for a few days once and my bill increased by about 30% from
normal.

--
(\__/) M.
(='.'=) Owing to the amount of spam posted via googlegroups and
(")_(") their inaction to the problem. I am blocking most articles
posted from there. If you wish your postings to be seen by
everyone you will need use a different method of posting.
See http://improve-usenet.org

"Mark" wrote in message
...
On Thu, 04 Dec 2008 10:41:15 GMT, YAPH wrote:

On Wed, 03 Dec 2008 17:36:58 +0000, John Rumm wrote:

Even if that were true (which I doubt), a large proportion are unlikely
to ever be heated via the immersion, given the added cost compared to
doing it with the boiler.

I come across a number of places where I find the immersion heater
switched on despite the central heating system working. To many
householders it's just a switch in the airing cupboard that does something
magical and if it happens to be switched on and everything works, they
leave it that way.

My God! I'd hate to see their leccy bill. My immersion was left on by
a "guest" for a few days once and my bill increased by about 30% from
normal.

If it is always on they do not notice an increase. The bulk of the energy
to re-heat the cylidner will be from a powerful gas boiler with a 3kW
immersion just assisting (expensivly so).

Or the amount of time people switch off the gas boiler in summer and use an
immersion. They must like losing money.

On Thu, 4 Dec 2008 03:08:58 -0800 (PST), wrote:

A stove with a boiler must, under all circumstances including
electricity power failure, have some means of dumping the heat. Be that
into a heatstore or once that is hot a radiator as well.

That's why you have a heat leak radiator

That's what I said. Doh...

(and a thermostatically controlled stove)

How does thermostatically controlled wood or coal burning stove work?

--
Cheers
Dave.

Dave Liquorice wrote:
On Thu, 4 Dec 2008 03:08:58 -0800 (PST), wrote:

A stove with a boiler must, under all circumstances including
electricity power failure, have some means of dumping the heat. Be that
into a heatstore or once that is hot a radiator as well.
That's why you have a heat leak radiator

That's what I said. Doh...

(and a thermostatically controlled stove)

How does thermostatically controlled wood or coal burning stove work?

switched fan, in the one I had to operate, once. More like a mini
bessemer converter..

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember "dennis@home"
saying something like:

In fact I have known an /uninsulated/ vented tank boil when an immersion
heater stat went faulty.

Indeed.
I came in from work one day some years ago and was greeted with rumbling
noise from the hall cubboard where the hot cyl was - the immersion
switch had been left on that morning and the stat had failed sometime
during the day. Luckily the overflow /vent was unblocked, but that had
never been checked as far as I know (rented property).

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember John Rumm
saying something like:

I was thinking of two - one where the plastic header tank got back
filled with hot and failed, and another where a cylinder ruptured and
dumped hot water on sleeping people below.

I thought they were both storage tank collapse incidents. What caused the
cylinder to rupture, do you know? Sounds almost as if it had gone
unvented.

The recentish one certainly was. I am not sure the older report actually
contained specific info - only "burst hot water cylinder".

Undersized vent scaling up, or inappropriate fitting of a gate valve in
the wrong place would seem like obvious culprits though.

There was one a few years back where the owner /renter had been nicking
power and the hot tank was on permanently. The stat had failed shut and
the chalky water over the years had closed the vent pipe down. Resulting
steam explosion took out the back wall of the house.

On Fri, 05 Dec 2008 15:03:37 +0000, The Natural Philosopher
wrote:

Dave Liquorice wrote:
On Thu, 4 Dec 2008 03:08:58 -0800 (PST), wrote:

A stove with a boiler must, under all circumstances including
electricity power failure, have some means of dumping the heat. Be that
into a heatstore or once that is hot a radiator as well.
That's why you have a heat leak radiator

That's what I said. Doh...

(and a thermostatically controlled stove)

How does thermostatically controlled wood or coal burning stove work?

switched fan, in the one I had to operate, once. More like a mini
bessemer converter..

Or thermostatcally controlled air intake.

On Fri, 05 Dec 2008 19:15:03 +0000, Grimly Curmudgeon wrote:

There was one a few years back where the owner /renter had been nicking
power and the hot tank was on permanently. The stat had failed shut and
the chalky water over the years had closed the vent pipe down. Resulting
steam explosion took out the back wall of the house.

So presumably the head of water from the tank pressurised the cylinder
raising the boiling point, and then when someone opened a tap the drop in
pressure caused the pressurised water to flash to steam in a classic steam
explosion.

I don't suppose the legality or otherwise of the leccy supply had anything
directly to do with it though.



--
John Stumbles -- http://yaph.co.uk

A: Because it messes up the order in which people read text.
Q: Why is top-posting a bad thing?

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember YAPH saying
something like:

On Fri, 05 Dec 2008 19:15:03 +0000, Grimly Curmudgeon wrote:

There was one a few years back where the owner /renter had been nicking
power and the hot tank was on permanently. The stat had failed shut and
the chalky water over the years had closed the vent pipe down. Resulting
steam explosion took out the back wall of the house.

So presumably the head of water from the tank pressurised the cylinder
raising the boiling point, and then when someone opened a tap the drop in
pressure caused the pressurised water to flash to steam in a classic steam
explosion.

That might well have been the sequence. Offhand I don't recall if anyone
was injured. It was mentioned on here actually, probably ~nine or ten
years ago and there was a link to a BBC (or perhaps a local rag) news
page.
Somewhere in the north of England, iirc. Middlesborough, perhaps?

I don't suppose the legality or otherwise of the leccy supply had anything
directly to do with it though.

Indirectly, iwt - if the immersion hadn't been on all the time I suspect
the stat would have lasted longer (and he might have turned the stat up
'cos he liked a piping hot bath for nowt), but also the vent pipe
wouldn't have chalked up so much.
Served the bugger right anyway.

On Fri, 05 Dec 2008 23:44:51 +0000, Grimly Curmudgeon wrote:

Indirectly, iwt - if the immersion hadn't been on all the time I suspect
the stat would have lasted longer (and he might have turned the stat up
'cos he liked a piping hot bath for nowt), but also the vent pipe
wouldn't have chalked up so much.

That bit puzzles me. Limescale typically blocks up pipes where cold fresh
water gets heated, so would be more likely to block the feed pipe to a HW
cylinder if it was hot enough throughout that the cold/hot water interface
was actually in the pipework rather than the lower regions of the cylinder
itself. The water in the vent pipe has already been heated and given up
its limescale.

And if it was oop North don't they have soft water up there anyway?



--
John Stumbles

If we'd known how much fun grandchildren are
we'd have had them first

"John Stumbles" wrote in message
. ..
On Fri, 05 Dec 2008 23:44:51 +0000, Grimly Curmudgeon wrote:

Indirectly, iwt - if the immersion hadn't been on all the time I suspect
the stat would have lasted longer (and he might have turned the stat up
'cos he liked a piping hot bath for nowt), but also the vent pipe
wouldn't have chalked up so much.

That bit puzzles me. Limescale typically blocks up pipes where cold fresh
water gets heated, so would be more likely to block the feed pipe to a HW
cylinder if it was hot enough throughout that the cold/hot water interface
was actually in the pipework rather than the lower regions of the cylinder
itself. The water in the vent pipe has already been heated and given up
its limescale.

And if it was oop North don't they have soft water up there anyway?

Depends on what part of oop north, some parts are very hard. They don't know
how lucky they are having soft water. They tend to use microbore pipes as
standard. I know around the Liverpool area microbore is the norm and they
all know how to fit it by rule of thumb too. The are experts at uncoiling
it. They are amazed when they see 15mm slapped in all over a house,
thinking that is something of 40 years ago.

On Fri, 05 Dec 2008 15:03:37 +0000, The Natural Philosopher wrote:

How does thermostatically controlled wood or coal burning stove work?

switched fan, in the one I had to operate, once. More like a mini
bessemer converter..

I'd call that a boiler not a stove. A stove is a passive lump of cast iron
with a door for shoving wood/coal in and a flue to take the smoke away.

Yes there are thermosatically controlled air vents but even if you shut
that down (How? This has to work without electric from the temperature of
the store) it takes a while for the significant amount of heat in the
firebox and mass of the stove to dissipate. Oh and a lump of ash could
stop the vent shutting properly, single point of failure...

--
Cheers
Dave.

Doctor Drivel wrote:

"John Stumbles" wrote in message
. ..
On Fri, 05 Dec 2008 23:44:51 +0000, Grimly Curmudgeon wrote:

Indirectly, iwt - if the immersion hadn't been on all the time I suspect
the stat would have lasted longer (and he might have turned the stat up
'cos he liked a piping hot bath for nowt), but also the vent pipe
wouldn't have chalked up so much.

That bit puzzles me. Limescale typically blocks up pipes where cold fresh
water gets heated, so would be more likely to block the feed pipe to a HW
cylinder if it was hot enough throughout that the cold/hot water
interface
was actually in the pipework rather than the lower regions of the
cylinder
itself. The water in the vent pipe has already been heated and given up
its limescale.

And if it was oop North don't they have soft water up there anyway?

Depends on what part of oop north, some parts are very hard. They don't
know how lucky they are having soft water. They tend to use microbore
pipes as standard. I know around the Liverpool area microbore is the
norm and they all know how to fit it by rule of thumb too. The are
experts at uncoiling it. They are amazed when they see 15mm slapped in
all over a house, thinking that is something of 40 years ago.

But doesn't Liverpool actually get much of its water from Wales - i.e.
not oop North? (Yes - I know - not all of it.)

--
Rod

Hypothyroidism is a seriously debilitating condition with an insidious
onset.
Although common it frequently goes undiagnosed.
www.thyromind.info www.thyroiduk.org www.altsupportthyroid.org

Dave Liquorice wrote:

Yes there are thermosatically controlled air vents but even if you shut
that down (How? This has to work without electric from the temperature of
the store) it takes a while for the significant amount of heat in the
firebox and mass of the stove to dissipate. Oh and a lump of ash could
stop the vent shutting properly, single point of failure...


They work by having a damn great bimetallic strip with a flat plate on
the end. When hot, it bends the strip so the plate covers the air
inlet. Seen them on (IIRC) Rayburns.

Andy

"Rod" wrote in message
...
Doctor Drivel wrote:

"John Stumbles" wrote in message
. ..
On Fri, 05 Dec 2008 23:44:51 +0000, Grimly Curmudgeon wrote:

Indirectly, iwt - if the immersion hadn't been on all the time I
suspect
the stat would have lasted longer (and he might have turned the stat up
'cos he liked a piping hot bath for nowt), but also the vent pipe
wouldn't have chalked up so much.

That bit puzzles me. Limescale typically blocks up pipes where cold
fresh
water gets heated, so would be more likely to block the feed pipe to a
HW
cylinder if it was hot enough throughout that the cold/hot water
interface
was actually in the pipework rather than the lower regions of the
cylinder
itself. The water in the vent pipe has already been heated and given up
its limescale.

And if it was oop North don't they have soft water up there anyway?

Depends on what part of oop north, some parts are very hard. They don't
know how lucky they are having soft water. They tend to use microbore
pipes as standard. I know around the Liverpool area microbore is the
norm and they all know how to fit it by rule of thumb too. The are
experts at uncoiling it. They are amazed when they see 15mm slapped in
all over a house, thinking that is something of 40 years ago.

But doesn't Liverpool actually get much of its water from Wales - i.e. not
oop North? (Yes - I know - not all of it.)

I believe it does, like Birmingham too.

On Sat, 06 Dec 2008 16:35:18 +0000, Andy Champ wrote:

(How? This has to work without electric from the temperature of
the store) it takes a while for the significant amount of heat in the
firebox and mass of the stove to dissipate. Oh and a lump of ash could
stop the vent shutting properly, single point of failure...

They work by having a damn great bimetallic strip with a flat plate on
the end. When hot, it bends the strip so the plate covers the air
inlet. Seen them on (IIRC) Rayburns.

Fine but that only regulates the device from the temperature of the device
not that of the store. It also doesn't shut the device down (as if off)
and you still have the problem of lots of residual heat.

--
Cheers
Dave.

On Sat, 06 Dec 2008 15:04:56 +0000, Rod wrote:

But doesn't Liverpool actually get much of its water from Wales - i.e.
not oop North? (Yes - I know - not all of it.)

Dunno about Liverpool. Birmingham gets its water from the Elan Valley
reservoirs in mid-Wales, and that's soft.

--
John Stumbles

What is a simile like?

John Stumbles wrote:
On Sat, 06 Dec 2008 15:04:56 +0000, Rod wrote:

But doesn't Liverpool actually get much of its water from Wales - i.e.
not oop North? (Yes - I know - not all of it.)

Dunno about Liverpool. Birmingham gets its water from the Elan Valley
reservoirs in mid-Wales, and that's soft.


Liverpool gets a load from Vyrnwy - a bit further north.

(Mind I think Shrewsbury and the other Severn towns are perhaps not
always so pleased with the Welsh water they get. :-) )

--
Rod

Hypothyroidism is a seriously debilitating condition with an insidious
onset.
Although common it frequently goes undiagnosed.
www.thyromind.info www.thyroiduk.org www.altsupportthyroid.org

replying to tom.harrigan, Me wrote:
If you own your property then you don't legally require annual certification.
But if your cylinder splits or the hot water side bursts a pipe and floods the
place, the insurance company will ask for your certification as it's part of
your contract with insurance company to "do all within your means to look
after insured property"

--
for full context, visit https://www.homeownershub.com/uk-diy...th-525079-.htm