Smoke in the House

A few days ago I was getting large amounts of smoke in the house when firing my boiler. It would be manageable as long as I didn't have the ash pan door open, but as soon as I would open that up, I would get tons of smoke at first from the firebox door. At this point I couldn't even fire it without filling the entire room with smoke. It soon got to the point where smoke would pour out of every tiny hole and seam in my flue pipe. There is a barometric damper installed on the flue pipe, and as you can imagine, it just puffed thick black smoke. At that point I smothered the fire and called a chimney sweep. He reported the chimney was pretty much clogged, and demonstrated after he cleaned it there was significant draw by holding a burning piece of paper in front of the firebox door and observing the smoke being drawn into the firebox. I should mention we also cleaned out the heat exchanger via both the access panel on the front, and by removing the flue pipe to get at the back. There was significant ash buildup in this area, we pulled an entire 5 gallon bucket out of there.

For two days after that I'm still having issues with smoke pouring back out of the firebox door as soon as I open it, and no matter how slowly I open it. If I keep the ash pan door completely closed, and my damper flap is mostly closed, I can still only get the door open maybe an inch before smoke starts pouring out. It didn't used to be this bad when I first started burning coal, but has just steadily gotten worse.

I'm not sure if the coal I'm burning is to blame or not. I started out with some bituminous coal my father in law had laying in his coal bin for years. This coal was a mixture of large lumps, maybe grapefruit sized, all the way down to an almost sandy consistency. It was very dark black and clean looking. This stuff burned great. It produced a small amount of grey smoke when I would first fire it, but other than that, I could stand there all day with the firebox door open. This next ton he got me came from 'his buddy who works at a mine' and it is supposedly Pittsburgh seam coal. It was still the cheapest of the cheap, he only charged us $37 a ton for it, and I'm starting to think I got what I paid for. This stuff is mostly 2-3 inch nuggets with a powdery coating over the surface of the lumps. They are a dustier almost grey color. It feels more solid than the first batch, almost like anthracite, but as soon as flames touch it, I get thick yellowish brownish smoke just roaring off of it and it stays that way for quite some time. It burns strangely too, after a few hours it starts to congeal like the other stuff, but it never really hardens, I don't know how else to describe it other than a gelatinous almost spongy mass. At this point it is producing thick black smoke, and if I poke it up and break the mass up, there is even more smoke.

A new symptom has also recently started with this stuff, my boiler has an oil gun on the back, and this smoke has taken to puffing out from the actual oil gun assembly itself, all the way back on the top of it where the breaker is to turn it on and off.

I keep my boiler temperature between 140 and 180, it is adjusted via a mechanical temperature gauge with a chain running down to a damper flap on the side of the ash pan. It used to run between 200 and 220 but I was having problems with the release valve blowing often, so I added some length to the chain which helped cool things down.

Can anyone please help me get this smoke situation sorted out?! It has gotten extremely frustrating and I'm just about ready to turn the dang oil gun back on. I would like to burn anthracite anyway as I understand it produces less smoke and ash and dust overall, but my father in law keeps showing up with this soft coal.

The only things I can think of are the coal is junk, or something is up with the barometric damper, as it is always 100% wide open. Maybe we jostled it around or something when we had the flue pipe off. I'm thinking that being wide open all the time has to be robbing draft that would otherwise help pull smoke up out of the firebox. Also another thing that changed was lowering the temperature of the boiler, and consequently the firebox to keep the release valve from blowing. Am I not burning hot enough to burn all the smoke off?

Any ideas and suggestions you guys have are very welcome at this point!

First off, the only way to tell the amount of draft you have is with a draft gauge. It will tell you just how strong the draft really is.

Those of us who burn anthracite usually use a Dwyer Mark II. If you have a Grainger's store near you, they should stock it.

Now make sure that your baro is flapping. Here on the eastern part of the state we have been dealing with some windy conditions so that may be the reason the baro is stuck open. A baro is there to PREVENT excessive draft. It's function is to open when it gets windy and blows across the top of the chimney thereby creating more draft. The baro prevents this by opening allowing more air to enter the chimney rather than drawing up through the fire.

You may want to take some foil and cover the baro for about a muinute before opening the doors. This would create more draft and maybe keep the smoke from pouring back into the house.

Another thing could be if your house is too tight. Try opening a basement window and see if that changes anything.

I'm not too familiar with burning Bit but I'm sure the bitty burners will be along.

Rick

Thanks for explaining exactly what a baro does, I was having a hard time getting a clear description of this. It has been kind of windy here too so possibly that is why it is wide open.

I will try covering it and opening an outside door in the basement when I fire it tomorrow morning and let you know if that helps. My house was built in 1980 and I never considered it to be very tight but I'll give it a shot.

Does it close on its own ??

Perhaps it needs to be adjusted. And the only way to know if it is adjusted is again back to the draft gauge.

If you have a window in the basement, perhaps you can leave that cracked open a bit ??

In my old shop, if I turned on the exhaust fan, it would back flow through the ash pan door. By opening a window when the fan was on prevented this.

You do have CO monitors and alarms don't you ??????

Rick

In the few minutes I was looking at it it hadn't closed at all. I could push it closed but it just swung back open. The damper got jostled around a bit when we had the flue pipe off and we put it back on with the damper being as close to horizontal as we could eyeball it. By horizontal I mean the opening pointing towards the side, not the top or bottom. There is a window in the other side of the basement I could keep cracked open.

I have smoke detectors and a CO detector on the main and upstairs floors.

You've got a clog somewhere. either you missed a buildup in the connecting pipe to the flue, you have a cap on the stack that's clogged, or your stack is blocked where the connecting pipe attaches @ the thimble. If it didn't behave this way before, and is now, you have an obstruction that you haven't yet discovered.

The exact bituminous coal you are getting will make a difference in performance and smoke/soot production. But, w/ any bit coal you need to have an 8" stack and a min. 8" flue. Large lumps of coal are best and, although pittsburgh coal is good, high BTU bituminous, it has two negative qualities for home heating; a very high volatile content and a VERY high coke button (it swells and agglomerates together). Other bituminous coals of large size, low coke button, and fired by "banking" the coal - push the hot coals to the back (or front) and fill the valley with fresh coal leaving the mountain of glowing coke exposed from the previous firing. Use some overfire or secondary air and keep the underfire air low. You will always have some smoke and soot (in a proper setup, it does NOT leave the firebox or chimney however) but a good bit coal will respond faster, have more BTU's and less ash than most anthracite. Getting good coal of the proper size and learning how to fire it (along with a good setup) make the difference.

This morning when I fired it, I tried the suggestion about covering the baro and leaving a door open in the basement. This seemed to help, most, if not all of the smoke stayed contained within the firebox the entire time I was poking it up and adding more coal. With the baro covered and the ash pan door open, the fire raged like I've never seen it before, but I was still able to have the firebox door open without much smoke escaping. I watched the baro a little while after I did this, and it was slowly flapping back and forth, only moving 1/4 to 1/2 inch from wide open.

I'm not sure where else to look for a clog. The chimney sweep cleaned out my cap, chimney, and flue pipe as well as the back of the heat exchanger. That is what that is called right? The area above the firebox where the water is heated? A few days ago, my father in law and I cleaned out this entire area from the front access panel, and the back by removing the flue pipe. We also brushed out the upper areas of the firebox at this time.

I have been keeping the vent on the firebox cracked open a bit, I have been told before coal needs some air on top. I have also kept the vent on the ash pan totally closed. I do have an 8" flue and chimney.

As for firing this stuff, I've been going side to side instead of front to back, always leaving a pile of glowing coals exposed on one side.

sounds like a draft gauge and maybe a new baro is in order here. I love Ricks advise above about the Baro

when starting a fire in a coal stove with poor draft I always cover the baro (if equipped) , set up my paper and sticks and then stuff some newspaper behind any baffle and directly into the stove pipe itself and light that a min. prior to lighting my "kindling set up" in the stove... to get a draft flowing (I'm not sure if you can do that in a coal furnace prior to lighting it but might be a good tip to create some draft beforehand?)

[quote="Matt328"] ......If I keep the ash pan door completely closed, and my damper flap is mostly closed, I can still only get the door open maybe an inch before smoke starts pouring out. It didn't used to be this bad when I first started burning coal, but has just steadily gotten worse......

......I keep my boiler temperature between 140 and 180, it is adjusted via a mechanical temperature gauge with a chain running down to a damper flap on the side of the ash pan. It used to run between 200 and 220 but I was having problems with the release valve blowing often, so I added some length to the chain which helped cool things down.

....but my father in law keeps showing up with this soft coal.

quote]

My $.02.... Get back to basics.... Fire needs a source of ignition, fuel, and enough air to support the combustion

Think about this from the standpoint of what changes were made before this started. You said that you were OK and then it started puffing at you.

From what your describing this started when your father in law started bringing soft coal around. I burn hard coal but I have picked up on here that you need tons of draft with soft coal, over fire air as well as underfire air and burn it hot. You may have had enough excess air in the room before you started burning this soft coal your father in law is bringing you. Make sure the room has enough free air with a window cracked open a couple of inches. Start by putting foil on that barometric damper to increase the draft through the stove.

make sure the flue pipes are clean, clean, clean. Make sure that all your gaskets and seals are good so you don't have air getting in where you don't want it.

Take some of that chain out and get your temps up

If the problem started when your father in law started bring the soft coal around, you may be using a piece of equipment that is set up for hard coal and needs to be set up for soft coal.

Put your setup back the way it was before the great smokeout and then change one thing at a time until you discover the culprit.

Rev. Larry

I should clarify, bituminous is the only coal I personally have ever burnt in this boiler. The first batch of it he brought up seemed to burn much nicer however than this Pittsburgh batch.

I did end up shortening the chain a bit this morning as it dipped into the low 20s here and the house was chilly when I woke up. This boiler has kept it 75 degrees in the house when the temperature was in the teens for a high, so I think I have it cooled off a bit too much.

I recently put a door on my boiler room to try and keep ash and soot from coming out into the rest of the basement, and based on what you guys are saying, it sounds like keeping that door closed might not be letting the fire get enough air. I will try for the next few days keeping that door open, and a window cracked in the basement.

I would very much like to burn anthracite as I've read elsewhere this boiler does much better with it than bituminous. Before though, I was having a hard time arguing with only $37 a ton, but now I'm learning you get what you pay for.

Make sure that all your gaskets and seals are good so you don't have air getting in where you don't want it.

I've seen smoke also puffing out around the oil gun. Can anyone offer any advice on getting this stopped? I'm worried that if smoke is able to puff out of there that air can also be getting in.

sounds like a draft gauge and maybe a new baro is in order here.

Do these go bad? The one that is there looks brand new, it isn't even hardly dirty, and there don't seem to be any serviceable or even adjustable parts on it for that matter.

http://www.dwyer-inst.com/Product/Pressure/Manome ... riesMarkII

I think this is the draft gauge that has been mentioned above. Where and how is this installed? It wasn't very obvious from the info online there.

Manometer Install

as for the door,if keeping it opens works,then just cut a 3" hole in the wall inside the boiler room then you will be able to shut the door and keep the dust inside.
Can't beat the price your paying for coal,if you can burn the bit coal safely, stay with it and welcome

$37 a ton????? Good grief... Topsoil around here is $36.50 a ton. Your coal is almost cheaper than dirt!!!

Dennis nailed it.

The baro will only go bad if it was bent due to dropping or getting blown off in a puffback. They should flutter freely. The axis pins should be level. The face of the baro should be plumb. Then the weight has to be placed correctly on 1 side or the other depending on whether the baro is installed in a vertical or horizontal section of pipe.

Then the connection to the draft gauge goes BEFORE the baro.

Also as Dennis said, IF the door is what created the tight condition, either a pipe in the wall or possibly cut a rectangular hole and install a furnace filter in the hole to stop the dust migration.

As far as the soot/smoke coming back through the oil gun, that would only happen if there is not enough draft on the chimney. Remember you do have a hole in the pipe for the baro and you aren't getting smoke back through there unless there is a huge down force wind or the chimney gets clogged. Same thing with anything regarding the fire box. As long as there is adequate draft, everything gets sucked up the chimney.

Rick

This afternoon, I cracked a window in another part of the basement with no closed doors into the boiler room, and did the tinfoil over the baro trick, and the smoke was pretty much under control. I was able to have the firebox open and poke it up pretty well without eating a face full of smoke.

I haven't seen any smoke coming back through the oil gun since I started opening a window/door and covering the baro. It's kind of a pain to get back there, so next time I fire, I'll try without covering the baro and see what happens.

if your baro is always open or flapping ,the draft is going up the chimney and pulling the smoke out thru the firebox and up the chimney creating a negitive pressure in the firebox(hense smoke pouring out every hole in the stove),you may need to adjust it with a manometer.Heres a PFD for adjusting the baro,it will get you closer,but only a manometer will give you the proper setting. http://www.fieldcontrols.com/pdfs/DC01575700.pdf -page 3