Friend of mine has a leaking HW cylinder. They have a very expensive
maintenance contract with BG so they have rung them up to come and have
a look at it.

"Oh you have got a very funny tank - its got 2 coils in it."

"Yes we know it has 2 coils, one is for the Gas the other is for the
back boiler behind the open fire in the lounge."

"It will take us ages to get hold of a cylinder of that size with 2
coils can you live without the back boiler?"

"Well yes its never been used since the gas was installed."

My question to the group, if you drain all the water out of a back
boiler system, does that preclude using the open fire? IE will you
melt/damage/distort the fireplace/boiler?

I don't think it will bother them if the answer to the question is no
you cant use the fire - as it has not been used in 25 years - but they
would like to know if it MUST not be used rather than they choose not to
use it.

--
Chris B (News)

On 16/02/2021 20:35, Chris B wrote:


My question to the group, if you drain all the water out of a back
boiler system, does that preclude using the open fire?Â* IE will you
melt/damage/distort the fireplace/boiler?


IIRC people would fill the back boiler with dry sand and the top vent
left open and carry on burning.worse case then would be sand spilling
into the fire as the steel oxidised.

On 16/02/2021 20:35, Chris B wrote:
Friend of mine has a leaking HW cylinder.Â* They have a very expensive
maintenance contract with BG so they have rung them up to come and have
a look at it.

"Oh you have got a very funny tank - its got 2 coils in it."

"Yes we know it has 2 coils, one is for the Gas the other is for the
back boiler behind the open fire in the lounge."

"It will take us ages to get hold of a cylinder of that size with 2
coils can you live without the back boiler?"

"Well yes its never been used since the gas was installed."

My question to the group, if you drain all the water out of a back
boiler system, does that preclude using the open fire?Â* IE will you
melt/damage/distort the fireplace/boiler?

I don't think it will bother them if the answer to the question is no
you cant use the fire - as it has not been used in 25 years - but they
would like to know if it MUST not be used rather than they choose not to
use it.

MUST not be used, unless made safe first.

http://www.heatingandventilating.net/womans-death-in-boiler-explosion-highlights-back-boiler-risk

On 16/02/2021 21:35, S Viemeister wrote:
On 16/02/2021 20:35, Chris B wrote:
Friend of mine has a leaking HW cylinder.Â* They have a very expensive
maintenance contract with BG so they have rung them up to come and
have a look at it.

"Oh you have got a very funny tank - its got 2 coils in it."

"Yes we know it has 2 coils, one is for the Gas the other is for the
back boiler behind the open fire in the lounge."

"It will take us ages to get hold of a cylinder of that size with 2
coils can you live without the back boiler?"

"Well yes its never been used since the gas was installed."

My question to the group, if you drain all the water out of a back
boiler system, does that preclude using the open fire?Â* IE will you
melt/damage/distort the fireplace/boiler?

I don't think it will bother them if the answer to the question is no
you cant use the fire - as it has not been used in 25 years - but they
would like to know if it MUST not be used rather than they choose not
to use it.

MUST not be used, unless made safe first.

http://www.heatingandventilating.net/womans-death-in-boiler-explosion-highlights-back-boiler-risk

The issue there was that the pipework had been capped and there was
presumably still some water left in the back boiler. Very bad idea.

As the other poster said, filling with sand AND LEAVING VENTED is
traditional, although TBH I am not quite sure what the sand filling
does. My woodburner is just a cast iron box; no firebricks so the back
panel sees direct heat. With a back boiler, it's the front face of the
boiler that sees direct heat. Its back face will get up to a similar
temperature by radiation, depending on how well it is cooled from
behind. You are not going to melt anything in a woodburner, although in
a coal stove (especially with smokeless fuel) the grate may get hot
enough to distort significantly.

If it were mine, and if I was unable to confirm with high confidence
that the pipework had not been capped (and perhaps bricked in) then I
would probably drill a few 3/8 inch holes in the boiler through the open
door. It should drill reasonably easily with a cordless drill and a
sharp HSS drill bit. Come to think of it, a couple of through-wall slits
with an angle grinder would have the same effect.

Also, back boilers are sometimes an optional "add-on" so it might be
possible to remove it, although you would probably have to do some
dismantling.

On 16/02/2021 20:35, Chris B wrote:
Friend of mine has a leaking HW cylinder.Â* They have a very expensive
maintenance contract with BG so they have rung them up to come and have
a look at it.

"Oh you have got a very funny tank - its got 2 coils in it."

"Yes we know it has 2 coils, one is for the Gas the other is for the
back boiler behind the open fire in the lounge."

"It will take us ages to get hold of a cylinder of that size with 2
coils can you live without the back boiler?"

"Well yes its never been used since the gas was installed."

My question to the group, if you drain all the water out of a back
boiler system, does that preclude using the open fire?Â* IE will you
melt/damage/distort the fireplace/boiler?


Conventional wisdom says you fill it with sand and then its OK
I didn't bother and 20 years later no issues..,

I don't think it will bother them if the answer to the question is no
you cant use the fire - as it has not been used in 25 years - but they
would like to know if it MUST not be used rather than they choose not to
use it.

It will be fine. At the worst you may melt or distort the steel boiler
housing if you get it to yellow or white hot



--
The theory of Communism may be summed up in one sentence: Abolish all
private property.

Karl Marx

On 16/02/2021 21:35, S Viemeister wrote:
On 16/02/2021 20:35, Chris B wrote:
Friend of mine has a leaking HW cylinder.Â* They have a very expensive
maintenance contract with BG so they have rung them up to come and
have a look at it.

"Oh you have got a very funny tank - its got 2 coils in it."

"Yes we know it has 2 coils, one is for the Gas the other is for the
back boiler behind the open fire in the lounge."

"It will take us ages to get hold of a cylinder of that size with 2
coils can you live without the back boiler?"

"Well yes its never been used since the gas was installed."

My question to the group, if you drain all the water out of a back
boiler system, does that preclude using the open fire?Â* IE will you
melt/damage/distort the fireplace/boiler?

I don't think it will bother them if the answer to the question is no
you cant use the fire - as it has not been used in 25 years - but they
would like to know if it MUST not be used rather than they choose not
to use it.

MUST not be used, unless made safe first.

http://www.heatingandventilating.net/womans-death-in-boiler-explosion-highlights-back-boiler-risk

Well making safe consists in simply disconnecting the pipes - in that
case it happened the very first time she lit the fire before the water
had any chance to evaporate and some numpty had left the pipes sealed



--
Socialism is the philosophy of failure, the creed of ignorance and the
gospel of envy.

Its inherent virtue is the equal sharing of misery.

Winston Churchill

On 16/02/2021 21:53, newshound wrote:
On 16/02/2021 21:35, S Viemeister wrote:
On 16/02/2021 20:35, Chris B wrote:
Friend of mine has a leaking HW cylinder.Â* They have a very expensive
maintenance contract with BG so they have rung them up to come and
have a look at it.

"Oh you have got a very funny tank - its got 2 coils in it."

"Yes we know it has 2 coils, one is for the Gas the other is for the
back boiler behind the open fire in the lounge."

"It will take us ages to get hold of a cylinder of that size with 2
coils can you live without the back boiler?"

"Well yes its never been used since the gas was installed."

My question to the group, if you drain all the water out of a back
boiler system, does that preclude using the open fire?Â* IE will you
melt/damage/distort the fireplace/boiler?

I don't think it will bother them if the answer to the question is no
you cant use the fire - as it has not been used in 25 years - but
they would like to know if it MUST not be used rather than they
choose not to use it.

MUST not be used, unless made safe first.

http://www.heatingandventilating.net/womans-death-in-boiler-explosion-highlights-back-boiler-risk

The issue there was that the pipework had been capped and there was
presumably still some water left in the back boiler. Very bad idea.

As the other poster said, filling with sand AND LEAVING VENTED is
traditional, although TBH I am not quite sure what the sand filling
does.

Square root of Sweet Fanny Adams, in reality. It probably helps to
spread the het evenlly prevednting hot spots

My woodburner is just a cast iron box; no firebricks so the back
panel sees direct heat. With a back boiler, it's the front face of the
boiler that sees direct heat. Its back face will get up to a similar
temperature by radiation, depending on how well it is cooled from
behind. You are not going to melt anything in a woodburner,

I beg to differ. I've melted grates...

although in
a coal stove (especially with smokeless fuel) the grate may get hot
enough to distort significantly.

And in an open wood fire. I can show you if you like. In the end
burning coal or charcoal is no different temperature wise



If it were mine, and if I was unable to confirm with high confidence
that the pipework had not been capped (and perhaps bricked in) then I
would probably drill a few 3/8 inch holes in the boiler through the open
door. It should drill reasonably easily with a cordless drill and a
sharp HSS drill bit. Come to think of it, a couple of through-wall slits
with an angle grinder would have the same effect.

Well there is access to the pipework at the tank isn't there? Simply
leave it open

If you cant disconnect more locally

IIRC most gravity fed systems also have a pressure valve to prevent
blowing up.

In short you really have to be a total arse and not only disconnect the
pipework but cap it at the fire itself to blow the **** up.


Also, back boilers are sometimes an optional "add-on" so it might be
possible to remove it, although you would probably have to do some
dismantling.

Don't thinks so with an open fire back boiler


--
Socialism is the philosophy of failure, the creed of ignorance and the
gospel of envy.

Its inherent virtue is the equal sharing of misery.

Winston Churchill

On 16/02/2021 20:44, AJH wrote:
On 16/02/2021 20:35, Chris B wrote:


My question to the group, if you drain all the water out of a back
boiler system, does that preclude using the open fire?Â* IE will you
melt/damage/distort the fireplace/boiler?

IIRC people would fill the back boiler with dry sand andÂ* the top vent
left open and carry on burning.worse case then would be sand spilling
into the fire as the steel oxidised.

That was what the guy who looked at ours wanted to do. You need
something behind it to take way some of the heat. The metal on its own
would heat up too quickly. It will run a lot hotter with dry sand in but
nowhere near as hot as a thin sheet of metal with air behind it would.

--
Regards,
Martin Brown

On 17/02/2021 10:00, Martin Brown wrote:
On 16/02/2021 20:44, AJH wrote:
On 16/02/2021 20:35, Chris B wrote:


My question to the group, if you drain all the water out of a back
boiler system, does that preclude using the open fire?Â* IE will you
melt/damage/distort the fireplace/boiler?

IIRC people would fill the back boiler with dry sand andÂ* the top vent
left open and carry on burning.worse case then would be sand spilling
into the fire as the steel oxidised.

That was what the guy who looked at ours wanted to do. You need
something behind it to take way some of the heat. The metal on its own
would heat up too quickly. It will run a lot hotter with dry sand in but
nowhere near as hot as a thin sheet of metal with air behind it would.

Thanks all for the comments (particularly the references to the
explosion and HSE advice) I will be sure to pass it on. It looks like
its not just them but any future house owners who need to be considered.

--
Chris B (News)

On 17/02/2021 11:41, Chris B wrote:
On 17/02/2021 10:00, Martin Brown wrote:
On 16/02/2021 20:44, AJH wrote:
On 16/02/2021 20:35, Chris B wrote:


My question to the group, if you drain all the water out of a back
boiler system, does that preclude using the open fire?Â* IE will you
melt/damage/distort the fireplace/boiler?

IIRC people would fill the back boiler with dry sand andÂ* the top
vent left open and carry on burning.worse case then would be sand
spilling into the fire as the steel oxidised.

That was what the guy who looked at ours wanted to do. You need
something behind it to take way some of the heat. The metal on its own
would heat up too quickly. It will run a lot hotter with dry sand in
but nowhere near as hot as a thin sheet of metal with air behind it
would.

Thanks all for the comments (particularly the references to the
explosion and HSE advice)Â* I will be sure to pass it on. It looks like
its not just them but any future house owners who need to be considered.

The key is not to seal it up with water inside

It can handle hot air but not steam

--
The lifetime of any political organisation is about three years before
its been subverted by the people it tried to warn you about.

Anon.

On 17/02/2021 07:55, The Natural Philosopher wrote:
On 16/02/2021 21:53, newshound wrote:
On 16/02/2021 21:35, S Viemeister wrote:
On 16/02/2021 20:35, Chris B wrote:
Friend of mine has a leaking HW cylinder.Â* They have a very
expensive maintenance contract with BG so they have rung them up to
come and have a look at it.

"Oh you have got a very funny tank - its got 2 coils in it."

"Yes we know it has 2 coils, one is for the Gas the other is for the
back boiler behind the open fire in the lounge."

"It will take us ages to get hold of a cylinder of that size with 2
coils can you live without the back boiler?"

"Well yes its never been used since the gas was installed."

My question to the group, if you drain all the water out of a back
boiler system, does that preclude using the open fire?Â* IE will you
melt/damage/distort the fireplace/boiler?

I don't think it will bother them if the answer to the question is
no you cant use the fire - as it has not been used in 25 years - but
they would like to know if it MUST not be used rather than they
choose not to use it.

MUST not be used, unless made safe first.

http://www.heatingandventilating.net/womans-death-in-boiler-explosion-highlights-back-boiler-risk

The issue there was that the pipework had been capped and there was
presumably still some water left in the back boiler. Very bad idea.

As the other poster said, filling with sand AND LEAVING VENTED is
traditional, although TBH I am not quite sure what the sand filling does.

Square root of Sweet Fanny Adams, in reality. It probably helps to
spread the het evenlly prevednting hot spots

It's not going to conduct particularly efficiently, and will stop
convection!


Â*My woodburner is just a cast iron box; no firebricks so the back
panel sees direct heat. With a back boiler, it's the front face of the
boiler that sees direct heat. Its back face will get up to a similar
temperature by radiation, depending on how well it is cooled from
behind. You are not going to melt anything in a woodburner,

I beg to differ. I've melted grates...

although in a coal stove (especially with smokeless fuel) the grate
may get hot enough to distort significantly.

And in an openÂ* wood fire. I can show you if you like. In the end
burning coal or charcoal is no different temperature wise

Wow, you must have had a hell of a draft (assuming it was a CI grate).
With a stove, wood does not need to be on a grate IME




If it were mine, and if I was unable to confirm with high confidence
that the pipework had not been capped (and perhaps bricked in) then I
would probably drill a few 3/8 inch holes in the boiler through the
open door. It should drill reasonably easily with a cordless drill and
a sharp HSS drill bit. Come to think of it, a couple of through-wall
slits with an angle grinder would have the same effect.

Well there is access to the pipework at the tank isn't there? Simply
leave it open

If you cant disconnect more locally

IIRC most gravity fed systems also have a pressure valve to prevent
blowing up.

In short you really have to be a total arse and not only disconnect the
pipework but cap it at the fire itself to blow the **** up.


Which is what I assume happened in the quoted case. It's easy enough to
imagine how all the visible iron pipework might be removed when an older
house is updated by adding an immersion or a gas boiler of some sort. As
you say, only a complete idiot would cap the boiler at the same time.

On 17/02/2021 16:03, newshound wrote:
On 17/02/2021 07:55, The Natural Philosopher wrote:
On 16/02/2021 21:53, newshound wrote:
On 16/02/2021 21:35, S Viemeister wrote:
On 16/02/2021 20:35, Chris B wrote:
Friend of mine has a leaking HW cylinder.Â* They have a very
expensive maintenance contract with BG so they have rung them up to
come and have a look at it.

"Oh you have got a very funny tank - its got 2 coils in it."

"Yes we know it has 2 coils, one is for the Gas the other is for
the back boiler behind the open fire in the lounge."

"It will take us ages to get hold of a cylinder of that size with 2
coils can you live without the back boiler?"

"Well yes its never been used since the gas was installed."

My question to the group, if you drain all the water out of a back
boiler system, does that preclude using the open fire?Â* IE will you
melt/damage/distort the fireplace/boiler?

I don't think it will bother them if the answer to the question is
no you cant use the fire - as it has not been used in 25 years -
but they would like to know if it MUST not be used rather than they
choose not to use it.

MUST not be used, unless made safe first.

http://www.heatingandventilating.net/womans-death-in-boiler-explosion-highlights-back-boiler-risk

The issue there was that the pipework had been capped and there was
presumably still some water left in the back boiler. Very bad idea.

As the other poster said, filling with sand AND LEAVING VENTED is
traditional, although TBH I am not quite sure what the sand filling
does.

Square root of Sweet Fanny Adams, in reality. It probably helps to
spread the het evenlly prevednting hot spots

It's not going to conduct particularly efficiently, and will stop
convection!


Â*Â*My woodburner is just a cast iron box; no firebricks so the back
panel sees direct heat. With a back boiler, it's the front face of
the boiler that sees direct heat. Its back face will get up to a
similar temperature by radiation, depending on how well it is cooled
from behind. You are not going to melt anything in a woodburner,

I beg to differ. I've melted grates...

although in a coal stove (especially with smokeless fuel) the grate
may get hot enough to distort significantly.

And in an openÂ* wood fire. I can show you if you like. In the end
burning coal or charcoal is no different temperature wise

Wow, you must have had a hell of a draft (assuming it was a CI grate).
With a stove, wood does not need to be on a grate IME

dunno really - nothing special. My wood burner DOES have a CI grate - a
new one - the last one burned and cracked






If it were mine, and if I was unable to confirm with high confidence
that the pipework had not been capped (and perhaps bricked in) then I
would probably drill a few 3/8 inch holes in the boiler through the
open door. It should drill reasonably easily with a cordless drill
and a sharp HSS drill bit. Come to think of it, a couple of
through-wall slits with an angle grinder would have the same effect.

Well there is access to the pipework at the tank isn't there? Simply
leave it open

If you cant disconnect more locally

IIRC most gravity fed systems also have a pressure valve to prevent
blowing up.

In short you really have to be a total arse and not only disconnect
the pipework but cap it at the fire itself to blow the **** up.


Which is what I assume happened in the quoted case. It's easy enough to
imagine how all the visible iron pipework might be removed when an older
house is updated by adding an immersion or a gas boiler of some sort. As
you say, only a complete idiot would cap the boiler at the same time.

Well that is plumbers for you. Generally reckoned to be the thickest of
all the trades






--
A lie can travel halfway around the world while the truth is putting on
its shoes.

I thought you fill the back boiler in a woodburner with sand so that it can be emptied and used as a water boiler later on, otherwise the tank will burst.

Might be wrong.

george


On Wednesday, February 17, 2021 at 11:41:28 AM UTC, Chris B wrote:
On 17/02/2021 10:00, Martin Brown wrote:
On 16/02/2021 20:44, AJH wrote:
On 16/02/2021 20:35, Chris B wrote:


My question to the group, if you drain all the water out of a back
boiler system, does that preclude using the open fire? IE will you
melt/damage/distort the fireplace/boiler?

IIRC people would fill the back boiler with dry sand and the top vent
left open and carry on burning.worse case then would be sand spilling
into the fire as the steel oxidised.

That was what the guy who looked at ours wanted to do. You need
something behind it to take way some of the heat. The metal on its own
would heat up too quickly. It will run a lot hotter with dry sand in but
nowhere near as hot as a thin sheet of metal with air behind it would.

Thanks all for the comments (particularly the references to the
explosion and HSE advice) I will be sure to pass it on. It looks like
its not just them but any future house owners who need to be considered.

--
Chris B (News)