When my mother's kitchen chimney was re-pointed a couple of years ago
the builder caught his 'helper' dropping bricks down it. After giving
him a telling off he took the flue above the wood burning stove apart
to remove the bricks. He then re-sealed the joins with fire cement.
This has now cracked up and largely fallen away.

Ever since the chimney was worked on my mother swears that the stove
hasn't been as good, she says it burns okay for an hour or two then
goes out. It has a metal disk with a small hole in that pivots at the
top of the stove to control airflow into a large flue. That flue goes
up then bends 45 degrees to the side then 45 degrees upright again.
The flue then disappears into brick where it undergoes two 90 degree
turns (accessible from the outside through a metal hatch) then goes
straight up the chimney.

Any suggestions as to a sealer for the joins in the flue? I see
Toolstation do a high temperature sealant on pg 202 (no. 66124) but
the description says it's only rated to 300 degrees C. Would that be
good enough?

Any suggestions as to why it's okay for a couple of hours only? It
doesn't seem to depend on external wind speed or direction. Could it
be the effect of a brick somewhere?

wrote:

When my mother's kitchen chimney was re-pointed a couple of years ago
the builder caught his 'helper' dropping bricks down it. After giving
him a telling off he took the flue above the wood burning stove apart
to remove the bricks. He then re-sealed the joins with fire cement.
This has now cracked up and largely fallen away.

Ever since the chimney was worked on my mother swears that the stove
hasn't been as good, she says it burns okay for an hour or two then
goes out. It has a metal disk with a small hole in that pivots at the
top of the stove to control airflow into a large flue. That flue goes
up then bends 45 degrees to the side then 45 degrees upright again.
The flue then disappears into brick where it undergoes two 90 degree
turns (accessible from the outside through a metal hatch) then goes
straight up the chimney.

Any suggestions as to a sealer for the joins in the flue? I see
Toolstation do a high temperature sealant on pg 202 (no. 66124) but
the description says it's only rated to 300 degrees C. Would that be
good enough?

Any suggestions as to why it's okay for a couple of hours only? It
doesn't seem to depend on external wind speed or direction. Could it
be the effect of a brick somewhere?

The HETAS installer I had used something like a silicone sealant tube - but
it was rated for loony temperatures. Sorry - I don't know its name.

Re going out - the first worthwhile test is to get some smoke matches (B&Q
sometimes have them with the gas related bits). Light a small fire and see
if the smoke from the match is sucked swiftly up the chimney.

Repeat with a normal fire at aorund the time it starts to fail.

I would have thought if you had a blocked flue, you would have known about
it (ie smoke everywhere).

Does the rest of the stove check out, particularly with respect to the inlet
air vents?

--
Tim Watts

On Oct 20, 9:59*pm, wrote:
When my mother's kitchen chimney was re-pointed a couple of years ago
the builder caught his 'helper' dropping bricks down it. After giving
him a telling off he took the flue above the wood burning stove apart
to remove the bricks. He then re-sealed the joins with fire cement.
This has now cracked up and largely fallen away.

Ever since the chimney was worked on my mother swears that the stove
hasn't been as good, she says it burns okay for an hour or two then
goes out. It has a metal disk with a small hole in that pivots at the
top of the stove to control airflow into a large flue. That flue goes
up then bends 45 degrees to the side then 45 degrees upright again.
The flue then disappears into brick where it undergoes two 90 degree
turns (accessible from the outside through a metal hatch) then goes
straight up the chimney.

Any suggestions as to a sealer for the joins in the flue? I see
Toolstation do a high temperature sealant on pg 202 (no. 66124) but
the description says it's only rated to 300 degrees C. Would that be
good enough?

Any suggestions as to why it's okay for a couple of hours only? It
doesn't seem to depend on external wind speed or direction. Could it
be the effect of a brick somewhere?


There could well still be a brick in the chimney. You need to get
sweeping brushes all the way through to confirm it is clear.
You also need to check the top of the chimney to make sure that tar
has not accumulated. (It mostly accumulates there). Tar usually can't
be dislodged by brushes, it has to be scraped off)

Four bends is really too many, the draught will be pretty marginal at
best.

On Oct 20, 9:59 pm, wrote:
When my mother's kitchen chimney was re-pointed a couple of years ago
the builder caught his 'helper' dropping bricks down it. After giving
him a telling off he took the flue above the wood burning stove apart
to remove the bricks. He then re-sealed the joins with fire cement.
This has now cracked up and largely fallen away.

Ever since the chimney was worked on my mother swears that the stove
hasn't been as good, she says it burns okay for an hour or two then
goes out. It has a metal disk with a small hole in that pivots at the
top of the stove to control airflow into a large flue. That flue goes
up then bends 45 degrees to the side then 45 degrees upright again.
The flue then disappears into brick where it undergoes two 90 degree
turns (accessible from the outside through a metal hatch) then goes
straight up the chimney.

Any suggestions as to a sealer for the joins in the flue? I see
Toolstation do a high temperature sealant on pg 202 (no. 66124) but
the description says it's only rated to 300 degrees C. Would that be
good enough?

no

ebay 130474972598 ??

Any suggestions as to why it's okay for a couple of hours only? It
doesn't seem to depend on external wind speed or direction. Could it
be the effect of a brick somewhere?

any maladjusted thermostatic controls?

Jim K

On Thu, 20 Oct 2011 13:59:41 -0700, combi6793 wrote:

When my mother's kitchen chimney was re-pointed a couple of years ago
the builder caught his 'helper' dropping bricks down it. After giving
him a telling off he took the flue above the wood burning stove apart to
remove the bricks. He then re-sealed the joins with fire cement. This
has now cracked up and largely fallen away.

Ever since the chimney was worked on my mother swears that the stove
hasn't been as good, she says it burns okay for an hour or two then goes
out. It has a metal disk with a small hole in that pivots at the top of
the stove to control airflow into a large flue.

There must be something on the 'inlet' side of things, so it can draw air
in - are those vents / valves / associated pathways clear? (does it
source combustion air from within the room or from outside?)

cheers

Jules

On Oct 21, 1:46 pm, Jules Richardson
wrote:


There must be something on the 'inlet' side of things, so it can draw air
in - are those vents / valves / associated pathways clear? (does it
source combustion air from within the room or from outside?)


It sources air from inside the kitchen, even before the chimney was re-
pointed we knew that using the kitchen extractor fan subdued the fire.
The inlet takes two forms, there are holes in the front of the stove
that are covered or exposed by moving cast iron discs or the stove
door can be opened and a fire excluder type mesh can be clipped over
the doorway. However we try to regulate the draft the fire still dies
away after about an hour or two.

On Oct 21, 9:33 am, Jim K wrote:
On Oct 20, 9:59 pm, wrote:



Any suggestions as to a sealer for the joins in the flue? I see
Toolstation do a high temperature sealant on pg 202 (no. 66124) but
the description says it's only rated to 300 degrees C. Would that be
good enough?

no

ebay 130474972598 ??


Looks interesting. The metal that makes the sections is pretty thin,
any idea if it would come apart again intact if we used that stuff?

Any suggestions as to why it's okay for a couple of hours only? It
doesn't seem to depend on external wind speed or direction. Could it
be the effect of a brick somewhere?

any maladjusted thermostatic controls?

It doesn't have a thermostat, just more or less draft/fuel.

On Oct 21, 9:03 am, harry wrote:
On Oct 20, 9:59 pm, wrote:



When my mother's kitchen chimney was re-pointed a couple of years ago
the builder caught his 'helper' dropping bricks down it. After giving
him a telling off he took the flue above the wood burning stove apart
to remove the bricks. He then re-sealed the joins with fire cement.
This has now cracked up and largely fallen away.

Ever since the chimney was worked on my mother swears that the stove
hasn't been as good, she says it burns okay for an hour or two then
goes out. It has a metal disk with a small hole in that pivots at the
top of the stove to control airflow into a large flue. That flue goes
up then bends 45 degrees to the side then 45 degrees upright again.
The flue then disappears into brick where it undergoes two 90 degree
turns (accessible from the outside through a metal hatch) then goes
straight up the chimney.

Any suggestions as to a sealer for the joins in the flue? I see
Toolstation do a high temperature sealant on pg 202 (no. 66124) but
the description says it's only rated to 300 degrees C. Would that be
good enough?

Any suggestions as to why it's okay for a couple of hours only? It
doesn't seem to depend on external wind speed or direction. Could it
be the effect of a brick somewhere?

There could well still be a brick in the chimney. You need to get
sweeping brushes all the way through to confirm it is clear.
You also need to check the top of the chimney to make sure that tar
has not accumulated. (It mostly accumulates there). Tar usually can't
be dislodged by brushes, it has to be scraped off)

Four bends is really too many, the draught will be pretty marginal at
best.

The odd thing is the fire burns when the chimney is cold, but well
after the chimney is hot the fire dies. I've seen spinning cowls on
chimneys that are supposed to increase draft, but I don't know if it
works.

On Oct 21, 12:05 am, Tim Watts wrote:


Re going out - the first worthwhile test is to get some smoke matches (B&Q
sometimes have them with the gas related bits). Light a small fire and see
if the smoke from the match is sucked swiftly up the chimney.

Repeat with a normal fire at aorund the time it starts to fail.


I'll try to get hold of some matches over the next few days.

wrote:

It sources air from inside the kitchen, even before the chimney was re-
pointed we knew that using the kitchen extractor fan subdued the fire.
The inlet takes two forms, there are holes in the front of the stove
that are covered or exposed by moving cast iron discs or the stove
door can be opened and a fire excluder type mesh can be clipped over
the doorway. However we try to regulate the draft the fire still dies
away after about an hour or two.

I hesitate to ask such an obvious question, but how does air get
into the kitchen?

Chris
--
Chris J Dixon Nottingham UK


Have dancing shoes, will ceilidh.

Chris J Dixon wrote:

wrote:

It sources air from inside the kitchen, even before the chimney was re-
pointed we knew that using the kitchen extractor fan subdued the fire.
The inlet takes two forms, there are holes in the front of the stove
that are covered or exposed by moving cast iron discs or the stove
door can be opened and a fire excluder type mesh can be clipped over
the doorway. However we try to regulate the draft the fire still dies
away after about an hour or two.

I hesitate to ask such an obvious question, but how does air get
into the kitchen?


Yes this all sounds a bit worrying. The extractor fan should not be run when
the stove is lit, indeed they shouldn't be in the same room.

What's being burnt and are there any smells? Smokeless fuels ( and charcoal)
can be deadly because there is no acrid smoke to warn.

Does the fire die down after this time because the room has become warm?

Is there an air circulation path whereby the warm are in the room vents
through the house or up another flue that exits higher than the one the
stove uses?

AJH

andrew wrote:
Chris J Dixon wrote:

wrote:

It sources air from inside the kitchen, even before the chimney was re-
pointed we knew that using the kitchen extractor fan subdued the fire.
The inlet takes two forms, there are holes in the front of the stove
that are covered or exposed by moving cast iron discs or the stove
door can be opened and a fire excluder type mesh can be clipped over
the doorway. However we try to regulate the draft the fire still dies
away after about an hour or two.
I hesitate to ask such an obvious question, but how does air get
into the kitchen?


Yes this all sounds a bit worrying. The extractor fan should not be run when
the stove is lit, indeed they shouldn't be in the same room.

What's being burnt and are there any smells? Smokeless fuels ( and charcoal)
can be deadly because there is no acrid smoke to warn.

Does the fire die down after this time because the room has become warm?

Is there an air circulation path whereby the warm are in the room vents
through the house or up another flue that exits higher than the one the
stove uses?

AJH
I've got couple of 6" pipes going to the underfloor cavity wherever
there is an fuel appliance or open fire - or in the bedroom into the
vented loft cavity.

If the OP has a suspended floor, Id drop a vent into it and put a grille
over the top.

On Oct 22, 9:17 am, Chris J Dixon wrote:

I hesitate to ask such an obvious question, but how does air get
into the kitchen?


I can't give a more specific answer than drafts.

I've now got hold of some smoke matches and will test the draft as per
Tim Watts' suggestion. I'll also try opening a window to see if that
helps.

Also, I've been up on a ladder and lowered a torch down the chimney on
a string. I can't see any tar or blockages. The external hatch, about
seven feet up, turns out to be something of a sloppy fit.

On Oct 22, 12:06 pm, andrew wrote:


Yes this all sounds a bit worrying. The extractor fan should not be run when
the stove is lit, indeed they shouldn't be in the same room.


We no-longer run the stove and the extractor at the same time.

What's being burnt and are there any smells? Smokeless fuels ( and charcoal)
can be deadly because there is no acrid smoke to warn.


Seasoned wood.

Does the fire die down after this time because the room has become warm?

Is there an air circulation path whereby the warm are in the room vents
through the house or up another flue that exits higher than the one the
stove uses?

The extractor fan has a flap to prevent drafts when the fan is not
running. There are no other vents than the stove's own flue. Air could
move through one of three doors but they are only briefly open when
the stove is lit.

In other words, I can not think of how warm air would vent higher than
the stove. Plus no vents have been changed since the problem developed.

On 23/10/11 21:25, wrote:
On Oct 22, 9:17 am, Chris J wrote:

I hesitate to ask such an obvious question, but how does air get
into the kitchen?


I can't give a more specific answer than drafts.

I've now got hold of some smoke matches and will test the draft as per
Tim Watts' suggestion. I'll also try opening a window to see if that
helps.

Also, I've been up on a ladder and lowered a torch down the chimney on
a string. I can't see any tar or blockages. The external hatch, about
seven feet up, turns out to be something of a sloppy fit.

and if you've got modern plastic windows theres no air coming in there,
so you have a problem of not enough incoming air...
- get a carbon monoxide alarm tomorrow!

[g]

The odd thing is the fire burns when the chimney is cold, but well
after the chimney is hot the fire dies. xxxx

Because its used most of the oxygen in the room?

Get a CO alarm tomorrow!

[g]