Question about EBT

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sbohlen

Member
Sep 18, 2008
80
Mid Coast Maine
OK. Ive got a total of about 7 hours on the T6 now. As I said in a previous post, I burner hard for a couple of hours this monring and then reloaded and cut the air back. After a few hours it started to look like the coals were going out. Lots of smoke from the chimney too. Also, the glass smoked up some. going to need cleaning I think. I opened the air back up some to get it going again and I am now letting it burn down since the outside temp has hit 60. Is this normal for the EBT? Should it be allowing more air in? Should I not close the air all the way down?
 
It sounds like the draft was minimal, probably due to the warm outside temps. When it gets cool outside you should be able to close it all the way down.
 
Good point. There does seem to be a lack of draft this afternoon. I was in the yard and the smoke was coming right down to ground level. Another question answered on hearth.com Thanks.
 
Something to think about is that the stove has to be hot enough to activate the EBT in the first place. Which it probably isn't if the air is closed down too soon after a reload. Take a look at Tom's excellent pics of how EBT works and you will see that the stove temp has to be high enough to push the EBT arm "over center" before it starts doing its thing.

http://chimneysweeponline.com/hoebt.htm
 
OK T6 owners. Temps are down in the 30s, I seem to have good draft and I have tried to close the air down completely at night. First I get a good fire going and temps up to sustain secondary burn, flue temps about 450F. Once I close the air down the flames gradually die down until only glowing coals remain. The flue temp drops to about 200 within the hour. Is this how the stove should burn with EBT? I'm worried about creosote build up overnight. Should I leave the air open enough to maintain a flame?
 
That's not how mine behaves at 45-50 outside and I suspect you are seeing a lot cooler temps. Try closing the air control in increments. I close it about half way once the new wood is burning well, stove top temp climbs to about 550 or 600, then wait another 15-30 minutes before closing it all the way down. But if I have really large splits then I might add another step. The stove seems to level out with the fully closed air control at about 500 with our softwood. My splits are on the large size, but definitely dry so far.

If you are not getting above 450 after secondary burning kicks in, I would look at the sized of the splits and the dryness of the wood. If you split some in half, is there any trace of dampness in the grain of the wood? If the wood is for certain good and dry, then I would look at the draft. Does the stove perform better with a nearby window cracked open? Can you describe the flue setup on the stove?
 
My wood is very dry. I have tried this with hardwood (about 20% moisture) and some cedar that has been in my basement abut 10 years (less than 15% moisture). Perhaps I am not getting the stove hot enough. I ordered an IR thermometer so I will check stovetop temps once it arrives. My stove pipe goes 3 feet up to a 90 then goes directly into an interior chimney that is about 30+ feet high (from the stove pipe entrance). The house isn't unusually tight and I have a fan blowing into the room with the stove (a trick I learned here for moving the heat around). the splits are releativly small since they were cut for my old cookstove but I am trying to use the larger ones for night burns.
 
I think it might be your wood.

Last year was my first year with the Summit and I couldn't close it down all the way. I assumed it was because I'm at the minimum chimney height and didn't have enough draft. This year I have slab wood and it's bone dry. I'm shutting the stove down all the way and getting crazy burn times. The heat output with it closed all the way is lower though. I'm getting the normal flames and secondaries for a few hours, then a it goes to a blue flame that's two or three inches high and stays that way for a long time.

I was at walmart looking for fire starters and saw a box of fire wood then had for sale that was open. It was slab wood. Somebody's getting rich. Ten bucks for a box, when I paid a hundred for a dump truck load of it. Maybe you should try a box and see if it's your problem.
 
Old House said:
My wood is very dry. I have tried this with hardwood (about 20% moisture) and some cedar that has been in my basement abut 10 years (less than 15% moisture). Perhaps I am not getting the stove hot enough. I ordered an IR thermometer so I will check stovetop temps once it arrives. My stove pipe goes 3 feet up to a 90 then goes directly into an interior chimney that is about 30+ feet high (from the stove pipe entrance). The house isn't unusually tight and I have a fan blowing into the room with the stove (a trick I learned here for moving the heat around). the splits are releativly small since they were cut for my old cookstove but I am trying to use the larger ones for night burns.

That should take off like a house of fire. Check the pipe with a level and make sure that the horiz. section is pitched uphill at least 1/4" per foot. Also, what is the dimension of the flue tile in the chimney?
 
To be honest, I'm getting pretty good burn times (8 hours) its just that I need to leave the air open about 25%. It seems EBT should alow you to shut it completely. maybe I could be doing better.
 
It could be weaker draft. Check the horiz pipe level and if you can, give us the tile size in the chimney. Nows a great time to fine tune the stove. In a month you may want it to perform at peak heat.
 
Not sure about my chimney diameter. I will measure it tomorrow. It seems like it is at least 6 inches square. I have about 16 inches of horizontal pipe that has no pitch to it. Could that be a problem?
 
Adding a little uphill action made a world of difference with my Jotul. And that was a short 10" run.
 
I'll give it a try and report back. Thanks.

Be Green, are you anywhere near Centralia? I sometimes get out to the Transalta power plant for work. beautiful country out there. good salmon at a place in olympia. can't remember the name of the place. Near some falls though.
 
If that chimney has a much larger size clay liner in it, that may be your draft problem.
Cross section area has been widely discussed and covered in many posts here.
 
I adjusted my horizontal section. My chimney is clay tile lined and it is rectangular shaped. It measures 4 inches by about 6.5 inches. i measured from the cleanout since it is raining here and I have a high, steep, roof. I looked with a mirror and everything looks clean and clear (as near as I can tell). I have a scheduled cleaning on November 1st so we will see if that helps any. I suppose any build-up on the sides could reduce draft. Does any one see a problem with those flue dimensions?

I will try again tonight to see if anything has changed with the horizontal adjustment.
 
4 x 6.5 ID is a tiny clay flue liner. I haven't seen anything that small. It gives a 26" cross-sectional area which is below the 6" round pipe cross sectional area of ~28 sq in. required for the stove. Add 2, 90 degree turns in the smoke path and a level horiz run and that can cause lazy draft.

My understanding is that ideally you'd want the cross sectional area to be about 25% larger than the stove pipe requirement or about 35 sq in for a 6" stove pipe. However, you do have a tall stack, which I would think when warmed up should draw ok. If adjusting the horiz. section's pitch doesn't help, the connector pipe could be modified to improve draft. The stove could be connected using a 45 off the stove, then a diagonal pipe going into another 45 that ties into the thimble.
 
Perhaps my measurements are wrong. The cleeanout is hard to access. It sure looks bigger when looking at it from the ground. The stove is on the middle chimney which has the liner protruding out of it. When I open the cleanout door, there is a ton of draft, almost sucked me up the chimney. The doorwas slightly loose, there are no gaskets on it. I would imaging that air leakage at the cleanout would reduce draft at the stove.
 

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Bingo! Take some duct tape and seal the cleanout door. If that radically improves the stove performance you are set. You can use silicone to make a permanent gasket after the sweep is done cleaning. Put a generous bead of silicone cement on the inside edge of the cleanout door, then latch it shut (or tape it back up).
 
Make sure the clean out door is tight & not leaking when closed. Any leaks will be taking away draft from the stove.
What is below the cleanout door to the bottom of the chimney? Is this dead, closed off space? Or is there some kind of leak or opening below that can also be robbing the stove of draft?
You do have the air lever to the left when starting correct?
You want any sucking & draft from the chimney to be pulling entirely from the stove only, any other areas, cleanout door etc, if leaking will be taking away from the stove.
 
Cleanout is in the cellar at the very bottom of the chimney. No other spots for leaks. I do have the lever to the left when starting and usually begin to close it after the surface magnet thermommeter on my stove pipe measures around 400F. This takes about 20 minutes of full open air with a load of hardwood. I sometimes leave the door unlatched, especially if I am starting the stove from cold. I then start to close it off incrementaly until i get down to about 1/3 to 1/4 open. Thats when I start to lose my flame.

The house has been staying at 67 today so I let the fire go out from this morning. I will be trying again this evening with a tightly sealed cleanout door. As Be Green said before, I want to fine tune everything so I am getting the best performace possible this winter. This stove is a Ferrari compared to my old cookstove, I want to get it going as good as it can get.

BTW, I am building a programable overtemp alarm for my stove pipe so my wife doesnt melt the stove while I am away. I will post pitures once its complete.
 
Try letting it get up to about 450 or 500 with lever wide open, then slide lever full to low.
 
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