what do you think this guys problem is (cat stove owners, and basement stove users look here)?

[MountainStoveGuy]

Original thread here:
http://ths.gardenweb.com/forums/load/firepl/msg1220420628579.html

Garden web scares me.


Here is one years' worth of trial and error work on a woodstove with a lowish flue temperature ~ 280 degrees at max burn, choked with wood and with the damper fully opened. (Good seasoned hard wood.)
I have an Englander ICD-24 stove that I got almost new and cheap on craigslist in an unfinished basement with an outside air supply in a 1300 square foot home with an outside terracotta-lined masonry chimney, 25' and at regulation height from the peak of the roof. It has never burned hot enough regardless of air supply, type of wood, amount of wood, etc, with or without the catalytic bypass opened or closed, and with the damper fully opened at all times.

Originally I was "over-flued" with a 9x12 chimney, so this year I lined it myself with a SS liner from the chimney store. (By the way, as long as you're not afraid of heights or of chiselling cement/brick, this is a fairly simple thing to do. Cost me $550 for the liner compared to estimates in the range of $2000-3000 for "professional" installation). The idea was that (in addition to supposedly increasing the safety of the set-up) the decreased flue size would increase draft due to less cooling in the chimney. THere was no appreciable difference.

I re-did the outside air supply with left-over 6" liner so that it now goes from a 4x8" window opening through 6" pipe which tapers to 4" at the stove intake. No difference.

I contemplated taking out the catalytic converter to "open up" the exhaust, but decided this would be self-defeating regarding creosote (which is why I'm concerned about the low operating temperatures in the first place), so nix that.

Incidentally, while I like the liner (not sure why, because it's not had any appreciable impact - it's probably just that I'm proud to have installed it myself), the rain cap that is on it now collects condensation and drips on the chimney cap and down the side of the chimney. THis appears to not be creosote, as it's colorless and clear, but it's not helping my masonry any.

So tonight, I got me a 3/8" Cobalt drill bit and drilled 14 holes in the air channel that runs from the intake to the front of the stove. I calculate that this creates about 1.5" square of additional cross sectional area for air draw - an increase of about 12% over the 12.5" square inches from the stock (4" diameter) intake.

This effected a temperature increase of about 10%, so now I'm burning at 320 degrees and it's not even that cold out (I expect it to do better when it's colder).

So for the first time since I've had this stove, there may actually be occasions where I will actually close the damper some. In fact I'm so pleased that I may open the holes to 1/2" with a bigger bit, which would increase the combined cross sectional area of the holes to 2.5" or a 25% increase from baseline.

I'm not sure why this stove is so oxygen starved. Either it's the specifis geometry or other charactistics of my particular set-up, or this stove was designed to be relatively oxygen starved to increase the advertised burn-time. Or it's for the catalytic converter operation, and now I've compromised that, but with my very low operating temperatures and condensation problems, something had to give.

I'm posting this to relate my experience and to see if others have had similar experiences that they would like to share. I'm prepared to hear that I'm crazy for modifying the stove also. BUt I figured that if I created any problem that I would tap the holes and screw in bolts or weld a plate over the holes and I'd be back to where I began...

Thoughts?

 

[MountainStoveGuy]

I shold have mentioned, that the problem is the basement in my opinion, not the stove. The outside air has to be coming from way above the stove which is why thats not working either. I dont understand folks who think that its necessary to modify there stoves, it like they think that there isnt a single englander ICD 24 that works on the market. Never would consider local conditions to be the problem.

 

[Roospike]

********** hh: ***********

 

[Roospike]

I was going to say chimney clean out door pulling draft but its been relined.

Prossess of elimination i guess .............
Open the down stairs window
Other things drafting from the room / ie: furnace , exhaust fan , dryer , hot water heater ect..
blow out the air inlet holes with compressed can air
make sure the air inlet damper is working correct
stuck baffle blanket covering exhaust hole
Drill a bunch of holes in your stove ;-)

 

[JMF1]

I don't know too much other than what I've learned here but, Roo....I think he meant that he drilled the holes into the air intake pipe (scrap liner in this case) not the stove itself. That he states helped........could it be something with it not getting enough air, maybe the whole air intake setup altogether? maybe the intake has too long of a run or negative pressure on it....hard to say from the post.
Just a guess......

 

[MountainStoveGuy]

the reason it wont work with a outside air kit is that the makeuop air for the stove is having to be pulled from way above the stove, outside airkits need to be level or below the stove.
the reason it didnt work without the outside air kit is beacuse his basement , like most, is under negative pressure. Basements are typically negative, main floors are typically neutral, and attics and upper levels are typically positive. Your house acts like one big chimney as heat rises in a home escapes out the attic. Your basement is typically not very leaky, and the rising heat puts pressure on the basement. It has no place to get make up air... well except for that chimmey.

 

[secondofangle]

Hi, guys, thanks for your input. I can maybe clear a few things up

the englander stove has an air intake on the bottom that accepts air from a 3-4" pipe into a channel about 1 inch deep, 6 inches across and 12 inches long running from front to back under the stove. The damper also runs in this channel. I drilled holes in the front of this channel, which, in effect, makes there be the stock air intake in teh bottom rear of the stove, and now my holes in thr front of the stove. I did not drill into the actual firebox. And this morning, I'm not sure I made much of a difference., because I'm burning at 250 again. Quite frustrating.

Now, in deference to all the experience you guys have, I have to say that from a purely physics and airflow standpoint, the idea of the pressure in teh basement doesn't make very much sense. With that outside air intake, the pressure in the basement is irrelevant. It's a closed system now. So all that matters is the pressure at the level of the air intake and the pressure at the top of the chimney. YOu could run that air intake 400 feet into the ground and back up to the stove, and it wouldn't make a bit of difference as far as pressure and flow are concerned (neglecting resistance to flow over that 400 feet), so long as the pressure at the top of the chimney is less than the pressure at the level of the air inlet. This is basic physics. And it's also why a siphon works (but in reverse). YOu can raise the hose up 400 feet over the ground, and as long as the outlet has a lower pressure than the inlet, she's gonna drain.

If I didn't have the outside air intake, then the pressure of the basement WOULD matter.

Does anyone think that a "better" stove, such as a Harman would be better?

Thanks for all the help!

SOA

 

[MountainStoveGuy]

It matters greatly when you try to pull combustion air from above the stove.. combustion air is supposed to be level or below the stove. Stoves have a hard time drawing air from up above. Also, if your air kit is on the leeward side of the house, the wind will make it pull the oppisit way you want it to. outside air kits are not the solve all answer, they work well in certain situations, but can hurt in othes....

Unless that stove is defective somehow... i guarentee you that any stove you put there will act the same way.

Yank out the stove, drag it up to the lawn, hook about 10' of pipe on it, and fire it up. I bet it works.

Ohh and welcome to hearth.com. You will find this site specificly tailored to woodburning.

 

[secondofangle]

That's a great idea, trying to burn it outside! It will be amajor PITA to get it out of the basement at this point now though. BUt if I unhook her for another reason, I just might try that....

So what would you do if you were me? There are plenty of folks who burn in the basement effectively aren't there?

And from talking to some of the stove dealers, they seem to believe that some stoves burn better than others.

Maybe there is a particular stove that will burn in my particular situation better than the englander?

Open to all suggestions,

Scott

PS - would taking the rain cap off of my SS liner help with the condensation problem?

And what do you think of the Harman Oakwood and Exception stoves?

 

[secondofangle]

Oh, and the other thing that argues against a problem with a low pressure basement is that I have no problems with back-puffing of smoke into the basement, and in fact opening the door HELPS the problem, doesn't make it worse. this fire is simply oxygen starved. Could it be that my catalytic converter is clogged? I thought of that, but even iwht the bypass opened, it doesn't burn very hot.

It will only burn hot with the door cracked.

Maybe the other users of Englander stoves don't know their flue temperatures and are having unrecognized creosote problems.

Oh, and as regards the process of elimination, I blew compressed air throught the air intake system. The furnace is PVC vented and not running. No exhaust fans. Openeing window doesn't help. Damper is working fine. What is a "stuck baffle blanket covering exhaust hole"?

Thanks, Scott

 

[MountainStoveGuy]

some houses are condusive to basement burning, but most are not. Brother Bart, a member here, burns a englander in his main living level, and a Jotul in his basement. Basement burning works for him, the same with earth harvester, he burns a quad 4300 in his basement and hasnt reported any problems. These are exceptions, not the norm. If your house is newer, and is tight the basement will be more negative then if its old and leaky. Mechanical rooms in basements create alot of the problems, there exausting alot of air and gas to the outside, and usually starve for make up air. Some appliances are supplied with make up air, but its a passive system. The chimney in these cases become the supply for the basement, and its very hard for a efficient stove to overcome the draw of the basement. The more efficient the stove, the worse this problem becomes.
Be leary of dealers that tell you that one brand of stove burns better then another. You can waste alot of money following that advice. A englander is made with cheaper materials, but in no way does it burn any worse or better then some of the top of the line stoves. All these stoves are similar in design.

What i would do in your case, is one of three things,
Try to find the least efficient stove you can find and try it ( it probably wont make any difference)
Install a pellet stove, there exaust is pressurized
Install a direct vent gas, room pressure doenst effect there performance what so ever.

Honestly, the best bet is to limit your wood burning to the main level of your house or higher. This is not the case for everyone, but your stove is telling you what it can and cant do. I would not waste money on a different stove untill yout try it somewhere else to elimate the stove being the issue.

 

[MountainStoveGuy]

sometimes the blanket on top of the smoke shelf will suck up and block the flue collar

Mechanical rooms arent the only culprit, tall tight houses will do the same thing. As hot air rises it pressurizes the attic and de pressurizes the basement. You dont have to have backpuffing, but i agree it would make the problem more clear.

It is possible that your cat is plugged, but that wouldnt make sense if you can bypass the damper. You should have never engaged your cat yet, that requires at least 500* stove temps...

 

[BrotherBart]

This Englander stove owner knows that he keeps the temp on that probe thermometer in his first section of flue pipe over four hundred except when letting the stove die down. Normally rises to 600-700 EGT on start-up before settling in at five hundred for a normal burn.

And he also has checked the chimney twice in the last month.

 

[secondofangle]

The catalytic converter thermometer, which goes in a hole in the side of the stove right above the converter, reads 700* now while the stovepipe thermometer reads about 250* (with the fire about died down to coals).

Is part of my problem reading the stovepipe thermomether instead of the catalytic converter one? What should each of them say? I've always read that creosote happens less than 250-300 (and that's consistent with what the stovepipe thermometer says). Seems like that's the important one, as that's what my chimney sees, not what's right above the catalytic converter.

I'll send you my address, and you can send a bill for all this advice

Scott

 

[MountainStoveGuy]

also unhook the chimney from the stove and light a smoking device, incense stick, cig, or what ever, and see how well the smoke falls up the chimmey...

 

[BrotherBart]

At what temp on the cat probe are you closing the cat damper and what temp is the cat probe showing when the cat is firing during the burn?

 

[secondofangle]

I always wait until it's above 500* before I close the cat convert bypass, and if it's chock full of wood, it will burn at 1000* on the cat thermometer. It's just that it's never hardly ever over 300 on the stovepipe thermometer unless the door's open. Which one should I care about?

 

[MountainStoveGuy]

If you 100% sure your getting good draft, the only other real possibliy is the stove is broke. Stoves should never need to be modified to operate properly.
A few more questions,
you mentioned relining your own chimney, what was there before the englander? A fireplace?
How well did this appliance run before you converted to a woodstove?
Is this stove rear vented? and if so, how far is the horizontal pipe run
If its verticly vented, how much verticle pipe do you have before the 90* and how long is the horizontal run to the chimney.
Do you have at least 1/4" per foot of rise on your horizontal pipe?
If you have alot of single wall pipe, have you considerd going to double wall to help keep heat in the chimney?
exactly how far above the stove is the outside air kit?

 

[MountainStoveGuy]

I always wait until it's above 500* before I close the cat convert bypass, and if it's chock full of wood, it will burn at 1000* on the cat thermometer. It's just that it's never hardly ever over 300 on the stovepipe thermometer unless the door's open. Which one should I care about?

that doenst make much sense to me. How can the cat be that hot and not the flue temps.. is the stove hot when the cat is at 1000*? i would think that it would be glowing red. Im not the cat guy here, i will let others comment on that.

 

[BrotherBart]

The cat probe is internal and he is using an external chimney thermo I would guess so the with an external pipe surface temp of 300 would indicate an internal pipe temp of around six hundred. The rest of the heat should be dissapating through the stove body from the cat chamber.

Though the cat probe temp looks low to me that stove should be hotter at that point than it is. I am waiting for a current cat stove operator to ring in but it seems to me the cat probe temp should be running up to 1,200 or so if the cat is in good condition.

 

[MountainStoveGuy]

i thought the cats platnium coating allowed it to operate in the 600* range......

 

[secondofangle]

THanks again guys for your comments. Let me address some of the other questions:

I'm getting pretty good draft.
The chimney was previously used for an old gas furnace, which I replaced for a PVC vented high-efficiency one. WHen I removed the old furnace, the chimney was spotless, and apparently it worked well for the vintage inefficient gas furnace.
Stove is top vented. THere is about 2 feet of vertical stove pipe, then a 90degree bend adn then 2 more feet and then into the SS liner (via masonry).
I don't think there is 1/4 inch rise. I know this would be ideal, but I don't think it's enough to cause the problems I'm describing.
I have single wall stove pipe.
THe outside air intake is about 5 feet above the stove intake. THe basement has a [relatively] short ceiling.

Part of the problem may in fact be that I'm measuring the outside of teh stove pipe. When I get home, I'm going to drill into teh stove pipe (I'm pretty good with a drill at this point )and put the probe thermometer in the pipe to see what teh inside temperature is.

But I reiterate, when the stove is running full blast and the catalytic converter probe is reading 1000 degrees (rarely ever more), the stovepipe surface thermometer reads 300 tops.

 

[MountainStoveGuy]

well, if you didnt have so much chimney that short up and out would cause problems, but you should have plenty of chimney to overcome that.
I believe you that your stove IS starving for air, and thats because that air kit is to high. When you open the door it gets O2 and its happy, but it wont get hot with the door open. My guess is you have a 2 story house on top of that basement and the pressure is to unbalanced.

just incase you dont have a manual, here is one.
http://www.englanderstoves.com/manuals/24-ICD.pdf

 

[Todd]

OK, I'll chime in here. My stove is in a finished basement. I have 3 thermometers on my cat stove. When I have a full load and the stove is chugging along my temps are as follows.

Cat probe- 1000
Stove top- 550-600
Stove pipe- 275-300 (magnetic thermometer)

Like BB said if your stove pipe thermometer was a probe type it would be much higher. It seems to me it's running the way it is sapose to, and doesn't put the heat out because the surrounding concrete is sucking up all the heat. If you fininsh off your basement you would probably get blasted out.

And I think if you disconnected the outside air from your stove, and just leave it by itself with maybe a flapper valve or something on the end it would help balance the pressure in your basement and act as a fresh air ventilator.

 

[Hogwildz]

I was going to say chimney clean out door pulling draft but its been relined.

Prossess of elimination i guess .............
Open the down stairs window
Other things drafting from the room / ie: furnace , exhaust fan , dryer , hot water heater ect..
blow out the air inlet holes with compressed can air
make sure the air inlet damper is working correct
stuck baffle blanket covering exhaust hole
Drill a bunch of holes in your stove ;-)

He shoulda got a Summit