I have a galvanized chimney, no bricks, no stones, no tile liner, just
one galvanized sheet metal pipe within another, to keep the outside
cool, and an oil furnace in the basement.

Is there supposed to be a cleanout in the house? Can I/should I put
one in?

No one who has been here to clean the furnace has ever said a word
about cleaning the chimney. And I usually watched, so I know they
didn't do it.

I also have a metal chimney for the fireplace. Each chimeny has a
metal chimney cap. Because I thought wood made fireplace chimneys
dirty, I even had a chimney sweep to clean the fireplace chimney and
after he left, I was sure he cleaned that one only and didn't even ask
me if I wanted the other one cleaned. I think I would have said yes.

Does it need it? I found a brush and poles at 80% off so I bought a
set but I can't go up on the roof in the winter. Brick chimneys have
cleanouts, but before the closet under the steps was full of junk,
I've been behind the furnace and I sure don't remember seeing anything
like that. Is it possible that my galvanized chimney has no
cleanout?

Should I put one in? Would it be hard? IIRC the chimney starts about
six feet above the basement floor.

TIA

On Mon, 20 Dec 2010 03:39:59 -0500, Joe wrote:

I have a galvanized chimney, no bricks, no stones, no tile liner, just
one galvanized sheet metal pipe within another, to keep the outside
cool, and an oil furnace in the basement.

Reading more webpages, I see that maybe one or both layers is
stainless steel, not galvanized.

On Dec 20, 8:51*am, Joe wrote:
On Mon, 20 Dec 2010 03:39:59 -0500, Joe wrote:
I have a galvanized chimney, no bricks, no stones, no tile liner, just
one galvanized sheet metal pipe within another, to keep the outside
cool, and an oil furnace in the basement.

Reading more webpages, I see that maybe one or both layers is
stainless steel, not galvanized.

All chimneys need cleaning. I would be very surprised if there is no
means. Usually there is a door at the bottom of the vertical bit. It
may be on the underside out of sight.

On Dec 20, 6:34*am, harry wrote:
On Dec 20, 8:51*am, Joe wrote:

On Mon, 20 Dec 2010 03:39:59 -0500, Joe wrote:
I have a galvanized chimney, no bricks, no stones, no tile liner, just
one galvanized sheet metal pipe within another, to keep the outside
cool, and an oil furnace in the basement.

Reading more webpages, I see that maybe one or both layers is
stainless steel, not galvanized.

All chimneys need cleaning. I would be very surprised if there is no
means. Usually there is a door at the bottom of the vertical bit. It
may be on the underside out of sight.

I'd say, no. Wood burning chimneys need cleaning but not oil or gas
furnaces.

"Joe" wrote in message
...
I have a galvanized chimney, no bricks, no stones, no tile liner, just
one galvanized sheet metal pipe within another, to keep the outside
cool, and an oil furnace in the basement.

Is there supposed to be a cleanout in the house? Can I/should I put
one in?

No one who has been here to clean the furnace has ever said a word
about cleaning the chimney. And I usually watched, so I know they
didn't do it.

I also have a metal chimney for the fireplace. Each chimeny has a
metal chimney cap. Because I thought wood made fireplace chimneys
dirty, I even had a chimney sweep to clean the fireplace chimney and
after he left, I was sure he cleaned that one only and didn't even ask
me if I wanted the other one cleaned. I think I would have said yes.

Does it need it? I found a brush and poles at 80% off so I bought a
set but I can't go up on the roof in the winter. Brick chimneys have
cleanouts, but before the closet under the steps was full of junk,
I've been behind the furnace and I sure don't remember seeing anything
like that. Is it possible that my galvanized chimney has no
cleanout?

Should I put one in? Would it be hard? IIRC the chimney starts about
six feet above the basement floor.

TIA

I am not sure about oil-fired. I have never seen a gas vent with a clean
out or one that needed it.

Unlike slow burning wood the fuels do not create creosote. A properly tuned
oil should create no soot.

Joe wrote:
I have a galvanized chimney, no bricks, no stones, no tile liner, just
one galvanized sheet metal pipe within another, to keep the outside
cool, and an oil furnace in the basement.

Is there supposed to be a cleanout in the house? Can I/should I put
one in?

No one who has been here to clean the furnace has ever said a word
about cleaning the chimney. And I usually watched, so I know they
didn't do it.

I also have a metal chimney for the fireplace. Each chimeny has a
metal chimney cap. Because I thought wood made fireplace chimneys
dirty, I even had a chimney sweep to clean the fireplace chimney and
after he left, I was sure he cleaned that one only and didn't even ask
me if I wanted the other one cleaned. I think I would have said yes.

Does it need it? I found a brush and poles at 80% off so I bought a
set but I can't go up on the roof in the winter. Brick chimneys have
cleanouts, but before the closet under the steps was full of junk,
I've been behind the furnace and I sure don't remember seeing anything
like that. Is it possible that my galvanized chimney has no
cleanout?

Should I put one in? Would it be hard? IIRC the chimney starts about
six feet above the basement floor.

TIA

The clean out is the end of the pipe where it connects to the stove. You
disconnect it and run a brush through it.



--
LSMFT

Simple job, assist the assistant of the physicist.

On Mon, 20 Dec 2010 04:06:02 -0800 (PST), Frank
wrote:

On Dec 20, 6:34*am, harry wrote:
On Dec 20, 8:51*am, Joe wrote:

On Mon, 20 Dec 2010 03:39:59 -0500, Joe wrote:
I have a galvanized chimney, no bricks, no stones, no tile liner, just
one galvanized sheet metal pipe within another, to keep the outside
cool, and an oil furnace in the basement.

Reading more webpages, I see that maybe one or both layers is
stainless steel, not galvanized.

All chimneys need cleaning. I would be very surprised if there is no
means. Usually there is a door at the bottom of the vertical bit. It
may be on the underside out of sight.

I'd say, no. Wood burning chimneys need cleaning but not oil or gas
furnaces.

I forgot, I should have mentioned part, or all?, of one season when
for some reason the flue almost filled up with soot. 6 inch pipe, I
think, with a full 2 inches of soot all around the inside and only 2
inches in the middle open, at least where it disconnected 3 feet from
the furnace. This is when the carbon monoxide detector went off,
actually waking me up. (I keep it in my bedroom.) I had a furnace man
from a reputable company clean the flue, and clean and adjust the
furnace, but he didn't clean the chimney, OR recommend that I have it
cleaned! And I was clinically depressed and didnt' think of it.

The first few years I was here the furnace men used at least a gauge
or two to adjust things -- at least they measured the stack
temperature -- but in recent years, they all, from different
companies, skip that. And I didn't argue with them, because I was in,
"They must know how to do it" mood. All they did was change the
nozzle and adjust the electrodes.

So for both the poor adjusting and the not telling me to clean the
chimney, now I'm very disillusioned. This time, I'm telling the
company to either send a guy who uses the gauges properly or don't
send anyone at all.

But don't I have to make sure the chimney is clean before I can expect
even a guy who uses gauges to adjust the furnace correctly?

On Mon, 20 Dec 2010 03:34:52 -0800 (PST), harry
wrote:

On Dec 20, 8:51*am, Joe wrote:
On Mon, 20 Dec 2010 03:39:59 -0500, Joe wrote:
I have a galvanized chimney, no bricks, no stones, no tile liner, just
one galvanized sheet metal pipe within another, to keep the outside
cool, and an oil furnace in the basement.

Reading more webpages, I see that maybe one or both layers is
stainless steel, not galvanized.

All chimneys need cleaning. I would be very surprised if there is no
means. Usually there is a door at the bottom of the vertical bit. It
may be on the underside out of sight.

It turns out there is no door. The flue just turns to vertical and
comes up to a horizontal black plate about 12 inches square at the
ceiling

It was hard to get in there, and I see now that I'd never seen the
chimney from the bottom before (only above the roof), because the
closet next to it which is my access is only 4 feet tall, underneath
the stairway landing. I can only look horizontally from there, not
up.

Plus there were three 2x4's in the way, one in the middle, and I'd
stored a folding card table up against them. When I tried to lean in
to the furnace area and look up, I was afraid I would lose my footing
and break my neck.

So I moved about 70 spare fence pickets, and the card table, and got
in there through the cobwebs, and there was no door!

There was just one of those segmented pieces for making a flue turn
corners, and from going slightly uphill, it turned vertical, up to the
center of a black metal plate about 12 inches square. I couldnt' see
but I suppose the flue detaches from the plate, and all the soot will
fall on my head** but I don't know if it will reattach easily, after
28 years.

** Maybe I can wear a hat, or a plastic bag. The space is very small,
only 16 inches wide by about 30 inches, half of that bounded by the
furnace on one side and the wall on the other. I was sorry I hadn't
left the front door unlocked and taken the cordless phone with me, in
case I got stuck in there, and couldn't crouch down to get back under
the stair landing, so I backed off and didn't get close enough to see
everything***.

Tomorrow I'll try to go in from the other side, but the water heater
is close to the furnace and I don't think I could have squeezed by
even when I was average weight. Now I'm fat but if I push my belly in,
it's no bigger than my ribcage, which is average size for a 5'8" man,
but I can't make it smaller.


Anyhow, I called a chimney sweep today but have to call back now with
this added info. The woman said he cleaned from both the basement and
the roof, 170 dollars. Another 170, no discount, for a second
chimney, even though he's already here and already on the roof!

Chimney sweeps used to be children (or small men?), because they
actually went down the chimneys I think, when chimneys were bigger. I
should remember to tell them they should send one of their thin guys.


***It's so good to be healthy again. A couple years ago, about a month
after abdominal surgery, I managed to move my 28-year-old washing
machine away from the wall about 30 inches, and I tried sitting down
behind it to tighten the belt. Each time, I could barely get up. I
couldn't get my legs underneath me, and there was nothing to hold on
to, except the laundry sink, which had no legs and was attached only
to the wall, and I was afraid pulling myself up with that would pull
the sink off the wall. I thought I'd be stuck there for weeks.
(Later I put two legs under the front of the sink.)

I was still tired from the surgery and staying in bed for more than 3
weeks. I coudln't tell if I'd actually tightened the belt while I was
sitting there, only after I got out, so a year later I went back with
a scribing tool, and a GM jack handle for leverage. Now it's tight
and should last for 5 or 10 years.

I am much stronger and more agile than for the month or two after the
surgery. But it was still miserable in that small space, no room to
stand up, since I was under the landing.

In article ,
mm wrote:

When I tried to lean in
to the furnace area and look up, I was afraid I would lose my footing
and break my neck.

First the airbag, and now this. You seem pretty preoccupied with not
wanting to break your neck.

On Mon, 20 Dec 2010 21:47:47 -0800, Smitty Two
wrote:

In article ,
mm wrote:

When I tried to lean in
to the furnace area and look up, I was afraid I would lose my footing
and break my neck.

First the airbag, and now this. You seem pretty preoccupied with not
wanting to break your neck.

You know, you're right! I didn't see the relationship before.

It's a good thing there are no airbags on the furnace.

On Dec 21, 1:37*am, mm wrote:
On Mon, 20 Dec 2010 03:34:52 -0800 (PST), harry
wrote:

On Dec 20, 8:51*am, Joe wrote:
On Mon, 20 Dec 2010 03:39:59 -0500, Joe wrote:
I have a galvanized chimney, no bricks, no stones, no tile liner, just
one galvanized sheet metal pipe within another, to keep the outside
cool, and an oil furnace in the basement.

Reading more webpages, I see that maybe one or both layers is
stainless steel, not galvanized.

All chimneys need cleaning. I would be very surprised if there is no
means. Usually there is a door at the bottom of the vertical bit. It
may be on the underside out of sight.

It turns out there is no door. * The flue just turns to vertical and
comes up to a horizontal black plate about 12 inches square at the
ceiling

It was hard to get in there, and I see now that I'd never seen the
chimney from the bottom before (only above the roof), because the
closet next to it which is my access is only 4 feet tall, underneath
the stairway landing. *I can only look horizontally from there, not
up.

Plus there were three 2x4's in the way, one in the middle, and I'd
stored a folding card table up against them. *When I tried to lean in
to the furnace area and look up, I was afraid I would lose my footing
and break my neck.

So I moved about 70 spare fence pickets, and the card table, and got
in there through the cobwebs, and there was no door!

There was just one of those segmented pieces for making a flue turn
corners, and from going slightly uphill, it turned vertical, up to the
center of a black metal plate about 12 inches square. *I couldnt' see
but I suppose the flue detaches from the plate, and all the soot will
fall on my head** but I don't know if it will reattach easily, after
28 years.

** Maybe I can wear a hat, or a plastic bag. *The space is very small,
only 16 inches wide by about 30 inches, half of that bounded by the
furnace on one side and the wall on the other. * I was sorry I hadn't
left the front door unlocked and taken the cordless phone with me, in
case I got stuck in there, and couldn't crouch down to get back under
the stair landing, so I backed off and didn't get close enough to see
everything***.

Tomorrow I'll try to go in from the other side, but the water heater
is close to the furnace and I don't think I could have squeezed by
even when I was average weight. Now I'm fat but if I push my belly in,
it's no bigger than my ribcage, which is average size for a 5'8" man,
but I can't make it smaller. * *

Anyhow, I called a chimney sweep today but have to call back now with
this added info. *The woman said he cleaned from both the basement and
the roof, 170 dollars. *Another 170, no discount, for a second
chimney, even though he's already here and already on the roof!

Chimney sweeps used to be children (or small men?), because they
actually went down the chimneys I think, when chimneys were bigger. I
should remember to tell them they should send one of their thin guys.

***It's so good to be healthy again. A couple years ago, about a month
after abdominal surgery, I managed to move my 28-year-old washing
machine away from the wall about 30 inches, and I tried sitting down
behind it to tighten the belt. *Each time, I could barely get up. * I
couldn't get my legs underneath me, and there was nothing to hold on
to, except the laundry sink, which had no legs and was attached only
to the wall, and I was afraid pulling myself up with that would pull
the sink off the wall. *I thought I'd be stuck there for weeks.
(Later I put two legs under the front of the sink.)

I was still tired from the surgery and staying in bed for more than 3
weeks. I coudln't tell if I'd actually tightened the belt while I was
sitting there, only after I got out, so a year later I went back with
a scribing tool, and a GM jack handle for leverage. *Now it's tight
and should last for 5 or 10 years.

I am much stronger and more agile than for the month or two after the
surgery. *But it was still miserable in that small space, no room to
stand up, since I was under the landing.

Well, who ever installed that chinmey was a cheapskate in your
parlance.
As there is no cleaning door it makes it neccessary to do it from the
roof and from inside the furnace. I t may be possible to have one
retro-.fitted if you can find the chimney manufacturer. It's quite
dangerous not having the flue checked out regularly.
Re chimneys and children, check out the "Water Babies" and Charles
Kingsley.
http://en.wikipedia.org/wiki/The_Wat...or_a_Land_Baby

On Tue, 21 Dec 2010 01:45:08 -0800 (PST), harry
wrote:

On Dec 21, 1:37*am, mm wrote:
On Mon, 20 Dec 2010 03:34:52 -0800 (PST), harry
wrote:

On Dec 20, 8:51*am, Joe wrote:
On Mon, 20 Dec 2010 03:39:59 -0500, Joe wrote:
I have a galvanized chimney, no bricks, no stones, no tile liner, just
one galvanized sheet metal pipe within another, to keep the outside
cool, and an oil furnace in the basement.

Reading more webpages, I see that maybe one or both layers is
stainless steel, not galvanized.

All chimneys need cleaning. I would be very surprised if there is no
means. Usually there is a door at the bottom of the vertical bit. It
may be on the underside out of sight.

It turns out there is no door. * The flue just turns to vertical and
comes up to a horizontal black plate about 12 inches square at the
ceiling

It was hard to get in there, and I see now that I'd never seen the
chimney from the bottom before (only above the roof), because the
closet next to it which is my access is only 4 feet tall, underneath
the stairway landing. *I can only look horizontally from there, not
up.

Plus there were three 2x4's in the way, one in the middle, and I'd
stored a folding card table up against them. *When I tried to lean in
to the furnace area and look up, I was afraid I would lose my footing
and break my neck.

So I moved about 70 spare fence pickets, and the card table, and got
in there through the cobwebs, and there was no door!

There was just one of those segmented pieces for making a flue turn
corners, and from going slightly uphill, it turned vertical, up to the
center of a black metal plate about 12 inches square. *I couldnt' see
but I suppose the flue detaches from the plate, and all the soot will
fall on my head** but I don't know if it will reattach easily, after
28 years.

** Maybe I can wear a hat, or a plastic bag. *The space is very small,
only 16 inches wide by about 30 inches, half of that bounded by the
furnace on one side and the wall on the other. * I was sorry I hadn't
left the front door unlocked and taken the cordless phone with me, in
case I got stuck in there, and couldn't crouch down to get back under
the stair landing, so I backed off and didn't get close enough to see
everything***.

Tomorrow I'll try to go in from the other side, but the water heater
is close to the furnace and I don't think I could have squeezed by
even when I was average weight. Now I'm fat but if I push my belly in,
it's no bigger than my ribcage, which is average size for a 5'8" man,
but I can't make it smaller. * *

Anyhow, I called a chimney sweep today but have to call back now with
this added info. *The woman said he cleaned from both the basement and
the roof, 170 dollars. *Another 170, no discount, for a second
chimney, even though he's already here and already on the roof!

Chimney sweeps used to be children (or small men?), because they
actually went down the chimneys I think, when chimneys were bigger. I
should remember to tell them they should send one of their thin guys.

***It's so good to be healthy again. A couple years ago, about a month
after abdominal surgery, I managed to move my 28-year-old washing
machine away from the wall about 30 inches, and I tried sitting down
behind it to tighten the belt. *Each time, I could barely get up. * I
couldn't get my legs underneath me, and there was nothing to hold on
to, except the laundry sink, which had no legs and was attached only
to the wall, and I was afraid pulling myself up with that would pull
the sink off the wall. *I thought I'd be stuck there for weeks.
(Later I put two legs under the front of the sink.)

I was still tired from the surgery and staying in bed for more than 3
weeks. I coudln't tell if I'd actually tightened the belt while I was
sitting there, only after I got out, so a year later I went back with
a scribing tool, and a GM jack handle for leverage. *Now it's tight
and should last for 5 or 10 years.

I am much stronger and more agile than for the month or two after the
surgery. *But it was still miserable in that small space, no room to
stand up, since I was under the landing.

Well, who ever installed that chinmey was a cheapskate in your
parlance.
As there is no cleaning door it makes it neccessary to do it from the
roof and from inside the furnace.

I talked to a couple chimney sweeps today, and they clean from the
roof regardless, it seems. Also from the basement regardless, since
they clean the stove pipe. This is there busy season, but I have one
coming next week.

I t may be possible to have one
retro-.fitted if you can find the chimney manufacturer. It's quite
dangerous not having the flue checked out regularly.
Re chimneys and children, check out the "Water Babies" and Charles
Kingsley.
http://en.wikipedia.org/wiki/The_Wat...or_a_Land_Baby

Thanks

On Dec 21, 11:14*pm, mm wrote:
On Tue, 21 Dec 2010 01:45:08 -0800 (PST), harry
wrote:





On Dec 21, 1:37 am, mm wrote:
On Mon, 20 Dec 2010 03:34:52 -0800 (PST), harry
wrote:

On Dec 20, 8:51 am, Joe wrote:
On Mon, 20 Dec 2010 03:39:59 -0500, Joe wrote:
I have a galvanized chimney, no bricks, no stones, no tile liner, just
one galvanized sheet metal pipe within another, to keep the outside
cool, and an oil furnace in the basement.

Reading more webpages, I see that maybe one or both layers is
stainless steel, not galvanized.

All chimneys need cleaning. I would be very surprised if there is no
means. Usually there is a door at the bottom of the vertical bit. It
may be on the underside out of sight.

It turns out there is no door. The flue just turns to vertical and
comes up to a horizontal black plate about 12 inches square at the
ceiling

It was hard to get in there, and I see now that I'd never seen the
chimney from the bottom before (only above the roof), because the
closet next to it which is my access is only 4 feet tall, underneath
the stairway landing. I can only look horizontally from there, not
up.

Plus there were three 2x4's in the way, one in the middle, and I'd
stored a folding card table up against them. When I tried to lean in
to the furnace area and look up, I was afraid I would lose my footing
and break my neck.

So I moved about 70 spare fence pickets, and the card table, and got
in there through the cobwebs, and there was no door!

There was just one of those segmented pieces for making a flue turn
corners, and from going slightly uphill, it turned vertical, up to the
center of a black metal plate about 12 inches square. I couldnt' see
but I suppose the flue detaches from the plate, and all the soot will
fall on my head** but I don't know if it will reattach easily, after
28 years.

** Maybe I can wear a hat, or a plastic bag. The space is very small,
only 16 inches wide by about 30 inches, half of that bounded by the
furnace on one side and the wall on the other. I was sorry I hadn't
left the front door unlocked and taken the cordless phone with me, in
case I got stuck in there, and couldn't crouch down to get back under
the stair landing, so I backed off and didn't get close enough to see
everything***.

Tomorrow I'll try to go in from the other side, but the water heater
is close to the furnace and I don't think I could have squeezed by
even when I was average weight. Now I'm fat but if I push my belly in,
it's no bigger than my ribcage, which is average size for a 5'8" man,
but I can't make it smaller.

Anyhow, I called a chimney sweep today but have to call back now with
this added info. The woman said he cleaned from both the basement and
the roof, 170 dollars. Another 170, no discount, for a second
chimney, even though he's already here and already on the roof!

Chimney sweeps used to be children (or small men?), because they
actually went down the chimneys I think, when chimneys were bigger. I
should remember to tell them they should send one of their thin guys.

***It's so good to be healthy again. A couple years ago, about a month
after abdominal surgery, I managed to move my 28-year-old washing
machine away from the wall about 30 inches, and I tried sitting down
behind it to tighten the belt. Each time, I could barely get up. I
couldn't get my legs underneath me, and there was nothing to hold on
to, except the laundry sink, which had no legs and was attached only
to the wall, and I was afraid pulling myself up with that would pull
the sink off the wall. I thought I'd be stuck there for weeks.
(Later I put two legs under the front of the sink.)

I was still tired from the surgery and staying in bed for more than 3
weeks. I coudln't tell if I'd actually tightened the belt while I was
sitting there, only after I got out, so a year later I went back with
a scribing tool, and a GM jack handle for leverage. Now it's tight
and should last for 5 or 10 years.

I am much stronger and more agile than for the month or two after the
surgery. But it was still miserable in that small space, no room to
stand up, since I was under the landing.

Well, who ever installed that chinmey was a cheapskate in your
parlance.
As there is no cleaning door it makes it neccessary to do it from the
roof and from inside the furnace.

I talked to a couple chimney sweeps today, and they clean from the
roof regardless, it seems. *Also from the basement regardless, since
they clean the stove pipe. * This is there busy season, but I have one
coming next week.

I t may be possible to have one
retro-.fitted if you can find the chimney manufacturer. *It's quite
dangerous not having the flue checked out regularly.
Re chimneys and children, check out the "Water Babies" and Charles
Kingsley.
http://en.wikipedia.org/wiki/The_Wat...Tale_for_a_Lan...

Thanks- Hide quoted text -

- Show quoted text -

Are you sure the flat black panel you described is not to be opened
for cleaning?

On Wed, 22 Dec 2010 00:14:52 -0500, mm
wrote:


Well, who ever installed that chinmey was a cheapskate in your
parlance.

My parlance?

As there is no cleaning door it makes it neccessary to do it from the
roof and from inside the furnace.

I talked to another chimney sweep company today**, and made an
appointment with them for next Wednesday, and she said it was almost
standard around here that the stove pipe bends and points up and meets
the bottom of the metal chimney in line, and that there is no
cleanout.

There is more than one way to do; things.

**I had to mention the lack of a cleanout to know whether to remove
things so the sweep could get around the back of the furnace to the
bottom of the chimney, because I thought he might do all the basement
vacuuming via the stove pipe, which is already accessible.

I guess besides brushing it from the roof, he's going to disconnect
the stove pipe from the chimney to clean it. The soot falls to the
bottom?

I talked to a couple chimney sweeps today, and they clean from the
roof regardless, it seems. Also from the basement regardless, since
they clean the stove pipe. This is there busy season, but I have one
coming next week.

I t may be possible to have one
retro-.fitted if you can find the chimney manufacturer. It's quite
dangerous not having the flue checked out regularly.
Re chimneys and children, check out the "Water Babies" and Charles
Kingsley.
http://en.wikipedia.org/wiki/The_Wat...or_a_Land_Baby

Thanks

On Wed, 22 Dec 2010 18:41:41 -0800 (PST), "hr(bob) "
wrote:



Are you sure the flat black panel you described is not to be opened
for cleaning.

Perhaps it is, but I still don't think it is called a cleanout.

I'm saying that because it's not a door that opens into the pipe,
which is how I conceive of a cleanout, but a place to separate the
pipe. (That may well be where the sweep vacuums it from.)

It's a "thimble", I'm pretty sure.

It's going to be very hard to see what he does unless I crowd in right
behind him between the water heater and the furnace. From the other
side, I have to go into that 4' high closet and then squeeze my body
between two studs and turn my head to the right to see the ceiling,
while he's trying to vacuum, and doesn't want to drop anything on my
head. (My neck used to turn more when I slept on my belly, but since
the surgery a couple years ago I've slept on my side, and my neck has
gotten less limber. when I lose enough weight, I'm going to sleep on
my belly again.)

You know, I shoudl have had this cleaned years ago, but not a single
furnace clearer ever suggested it, even the time the soot was 1.5"
thick all around the inside of hte 5" stove pipe, with only a 2" hole
in the middle for the combustion gas. He cleaned the entire stove
pipe that day, but if the stove pipe was that sooty, it's likely that
the chimney was dirty too.

In addition some webpages said that the sulfur in the oil soot could
combine with water if the chimney cap was off and it rained in**, it
would make (weak?) sulfuric acid which could eat through the stainless
steel. That's bad. But on further looking, I saw that the two
webpages that made that sound like a real likelihood were chimney
sweep pages, who have an interest in scaring people into frequent
cleaning. **Does it require rain? Isnt' there condensation sometimes
of the exhaust gases, which are supposed to be C02 and H20. I know
the hot draft is supposed to prevent condensation in the chimney, but
I think I've read that it happens some times, at least in fireplace
chimneys.

Other pages said the fraction (or percent?) of sulfur in the northeast
is .15 and the states from Maryland to Maine have agreed to lower that
to .002, but they say they're doing that to prevent acid rain, not to
keep metal chimneys from damage, so I still think that while a bad
draft is a real possibility, it's not likely I've damaged the chimney.

Home oil furnaces use #1 or #2 oil, but there is also #4 and #6, used
in factories iiuc. It said that lowering the sulfur in #2 would also
benefit #4 which is a mixture of 2 and 6. Apparently the high
percentage in 6 can do damage to metal chimneys, but so far, only
chimney sweeps and one other page said home stainless steel was
vulnerable. What's done is done, but if I ever need a new chimney I
guess it will be thousand or two

**And my chimney cap was off for a couple months. It blew off and a
month later my neighbor offered to climb up and put it back on for me.
Then a year later, it blew off again, got damaged when it landed on
the ground, and I got the chimney sweep to put on another one. So that
was a couple months without a cap. I only asked him to clean the
fireplace chimney, he didn't suggest cleaning the furnace, one, he
only charged me for one chimney, and it wasn't until after he left, I
thought about the furnace chimney.