Why isn’t it burning right?

[Apprentice_GM]

G'day All,

My stove ain't burning right, that is, as well as it was last week. I've had it for 3 years, just started my 4th winter, only burn at night so always cold starting, and have become accustomed to it's usual performance, which as of about 4 days ago changed, and I can't figure out why.

At the moment I'm burning hardwood fence post / rails / palings, which are "completely" seasoned. You know, been standing outside for 50 years and torn down for new metal fencing or new estates. I scrounge them by getting the fencing contractors to drop them off at my place, as long as they are unpainted (our hardwood fences are untreated, only the new pine fencing gets various pressure and chemical treatments) and cut them up.

To me the only 2 factors I can think of affecting bad / slow starting / cool burning fires are air issues (not enough, or airflow blocked somewhere eg a birds nest) or bad fuel (wet / unseasoned wood) and I just can't think what I'm missing.

My wood is stored on a porch, out of the rain, and although we are having a bit of a big wet, the wood seems fine as I'm loading it, certainly not obviously wet or even damp. It's clearly seasoned. I have my air intakes open to the max. The only thing I haven't done is pulled apart the flu as it's raining a fair bit and I'm not keen on doing that on a wet roof and when we need the fire anyway (even if it's not working properly). The draft is a lot harder to get going than normal, but after quite a while it appears to be drawing OK.

Anyone got any suggestions for me to look into? I did have a look inside my flu / chimney a few weeks ago before burning season started and there was no creosote buildup. I brushed it anyway and got maybe half a cup of soot from 18 foot of 6" active so it's clean.

It seems to be a sudden change.

I might pull apart the baffle creating secondary burn and see if something is blocking the bottom before pulling the cowl off.

Any thoughts?

 

[jebatty]

Be sure your chimney is clean and no blockage, that the stove exhaust path to the chimney is clean and without blockage, and your wood is dry. Has to work ... but you mention rain. Perhaps the rain and high humidity in the atmosphere is impeding draft (heavy air, takes more heat to get a draft going well). Be sure you have a good air supply to the stove, crack a window, etc., to let in extra air. You may have to burn the stove hotter to increase the draft in mild and/or wet weather. Good luck.

 

[savageactor7]

I take it you're patiently letting the fire get up speed with smaller splits before adding the larger ones? If you don't have established hot coals just be patient and hold off on adding the larger splits.

 

[LLigetfa]

Perhaps the rain and high humidity in the atmosphere is impeding draft (heavy air, takes more heat to get a draft going well).

Ja, that'd be my guess too. Blame it on the barometer. Does the smoke spill down the outside of the chimney? In weather like described I have trouble getting the smoke to rise.

 

[Apprentice_GM]

I take it you're patiently letting the fire get up speed with smaller splits before adding the larger ones? If you don't have established hot coals just be patient and hold off on adding the larger splits.

Yep, same as the last few years . . . I actually build top-down fires, have found them to be far superior to the usual type.

jebatty, I have wondered about the rain and humidity and if that might affect my fire, it hasn't in the past. It might explain some of the problem, certainly on startup. However if I get a nice coal bed, which eventually I do, then add a new load of dry, extremely seasoned palings, normally they would torch up like petrol / gas, but now they take a lot longer, and I need to crack the fireplace door to really get them going, whereas before I could open the intake for 15 minutes, get 'em roaring, then close it down to 15% (smallest setting possible in my fire - prevents "0" and smoke choking which some people in my neighbourhood love to do on their older models) and leave her be.

In times of really high humidity does that also affect new load inflammation?

As soon as it stops raining I'm going to remove the cowl and check out my chimney / flu - I'm sure it is clean but it might be blocked by a bird or some rodent or something.

 

[LLigetfa]

Do you draw outside air for combustion? Could the makeup air to the home have changed? I was having the issues you describe and came to the realization that my HRV intake was all clogged up with cotton fluff from the trees. The HRV was pulling air out but not letting air in. I draw outside air (OAK) for secondary combustion but use room air for the doghouse (primary) which has a big influence on the fire.

There's been cases posted here where a poorly seated attic hatch changed the stack effect from one year to the next.

 

[smokinj]

I take it you're patiently letting the fire get up speed with smaller splits before adding the larger ones? If you don't have established hot coals just be patient and hold off on adding the larger splits.

+1 thats how hedge apple acts at frist as well. softwods will bring your temps up quicker

 

[Apprentice_GM]

Do you draw outside air for combustion? Could the makeup air to the home have changed? I was having the issues you describe and came to the realization that my HRV intake was all clogged up with cotton fluff from the trees. The HRV was pulling air out but not letting air in. I draw outside air (OAK) for secondary combustion but use room air for the doghouse (primary) which has a big influence on the fire.

There's been cases posted here where a poorly seated attic hatch changed the stack effect from one year to the next.

I only draw room air, no OAK. I have a single storey brick veneer dwelling and haven't changed any of the seals to windows or doors in the last few days. The only thing I can think of is the high humidity with regard to draft, although strange I haven't experienced it in the last 3 winters and we have had plenty of rainy days over that time, or some bird / rodent getting jammed in the 6" flu.

Or possibly the ultra seasoned wood drawing heaps of humidity despite not appearing damp. I did a test tonight by putting some wood next to the fire and ensuring it was dry, warm to touch before burning it by placing the new load on a nice hot bed of coals, and same problem, so I'm back to airflow / draft I think.

I appreciate the other suggestions eg split size and softwoods, hopefully it will help others following this thread later, but for me the thing I am doing has changed yet the performance is markedly different the last few days compared to last week and last month and last year and the year before that etc.

I just can't think what other variables might be in play. As soon as it stops raining I'm removing the cowl and checking the flu.

 

[summit]

which stove is it? have you checked the baffle area? excess flyash can block off areas required to be open for proper draft. knowing the brand and model would help.

 

[savageactor7]

Well after some thought I've concluded it might not be your chimney...mostly cause you'd smell smoke. To rule that out next time before starting a fire dissemble the stove pipe from the flue and mirror the chimney.

If the mirror reveals the chimney to be clear the next couple of 3 days start a conventional fire from the bottom up...the way cave men did it. Do that an note any difference.

I remember when you tore out that gorgeous inefficient fireplace of your...that took a lot of balls. I respect folks that can do that.

 

[jebatty]

jebatty, I have wondered about the rain and humidity and if that might affect my fire

I notice a difference based on weather and temperature. Fire starts and burning are always much better the colder and drier the outside air/weather. I don't have a problem, just that it takes a bit more care to use plenty of kindling to get a good draft going before putting on larger splits.

 

[Apprentice_GM]

which stove is it? have you checked the baffle area? excess flyash can block off areas required to be open for proper draft. knowing the brand and model would help.

Summit, all my equipment is in the signature, stove first. I cleaned out the baffle before this winter and I've only been burning a few weeks and only night burns at that, and with super seasoned wood, so I don't think the baffle is blocked from ash. Certainly seems strange ash buildup would make such a sudden and dramatic difference. There could be a dead bird or rodent (which might have snuck in through the cowl) in there though which could be doing it.

 

[carinya]

I don't think it's the stove system. It's the climate !

Central Coast NSW Australia doesn't get cold enough to feed a wood burner - last time I looked it was 55F in Terrigal and 99% humidity at 11am tomorrow :cheese:

You should be out in the surf getting refreshed :lol:

Here, in humid Ohio, I would be having a hard time getting any draw at 50F

Could certainly do with some good old hardwood Aussie fence palings come December.

Cheers

 

[LeonMSPT]

"Sheet" of creosote loosed from the liner and fell across the pipe, holding your draft back but not enough to make smoke back in? Not there, can't see it, only reading on a page. Sometimes happens...

Good luck to you, it'll work out.

which stove is it? have you checked the baffle area? excess flyash can block off areas required to be open for proper draft. knowing the brand and model would help.

Summit, all my equipment is in the signature, stove first. I cleaned out the baffle before this winter and I've only been burning a few weeks and only night burns at that, and with super seasoned wood, so I don't think the baffle is blocked from ash. Certainly seems strange ash buildup would make such a sudden and dramatic difference. There could be a dead bird or rodent (which might have snuck in through the cowl) in there though which could be doing it.

 

[Apprentice_GM]

"Sheet" of creosote loosed from the liner and fell across the pipe, holding your draft back but not enough to make smoke back in? Not there, can't see it, only reading on a page. Sometimes happens...

Good luck to you, it'll work out.

Hey Leon, thanks for your thoughts

wrt the sheet of creosote, er, next to impossible. I don't get creosote buildup. Been burning old railway sleepers, hardwood fencing, used timber / lumber and some very well seasoned split hardwood and after 3 years the flu was a little sooty at the top but no creosote. I think my fuels are too seasoned, the flu (~18 foot long) too short and too well insulated (complicated, but it's quad in room, then triple in attic, then double walled externally), and outdoor temps too warm, for creosote buildup. My fire burns hot and smoke free, except on startup (and except for right now!), and besides as posted earlier, I cleaned the half cup of soot accumulated from 3 years of burning before this winter started and I've only been burning at night and for a few weeks, and again, with that super seasoned hardwood fencing. The MC readings are well under 10% but vary a bit with weather patterns.

Twice I've been up the ladder today and twice been driven back inside with heavy showers. We're getting a lot of rain, 93mm in the last 24 hours, almost 4 inches, mostly in heavy showers. I'm going to pull the baffle out and cowl off, weather permitting, and check the flu this afternoon. Bit of a hassle but has to be done!

 

[Apprentice_GM]

I don't think it's the stove system. It's the climate !

Central Coast NSW Australia doesn't get cold enough to feed a wood burner - last time I looked it was 55F in Terrigal and 99% humidity at 11am tomorrow :cheese:

You should be out in the surf getting refreshed :lol:

Here, in humid Ohio, I would be having a hard time getting any draw at 50F

Could certainly do with some good old hardwood Aussie fence palings come December.

Cheers

G'day carinya, actually it does get cold enough (imho) to burn overnight - the last 2 weeks have been 0 degrees to 7 degrees celsius overnight which is low 30's and 40's F I think

I have enjoyed a wave lately with 4 to 6 foot swells and the good news is the water temps are still mild, around 19 degrees C (66 F?) but the air temps are "refreshing"

You are welcome to as many palings as you want Free to me and plenty of them - can be a hassle cutting up, but you won't get better seasoning - my favourite is still ex-railway sleepers, heavy ironbark sitting in the elements for 40 to 50 years - murder on saws but awesome burning. Is this an option for woodburners in the USA?

Have you visited Terrigal? It's 15 minutes from me (Glenning Valley).

 

[begreen]

If nothing has changed on the stove or flue, then the first place I'd examine is the flue cap. See if it the screen is getting plugged. The second place I'd examine is the wood. Try splitting it. If the freshly exposed surface feels cool and damp when you put it up to your cheek, then that is likely the problem.

I'm curious about burning old railway ties (sleepers?). Normally these are creosote or preservative soaked in this country. Are they raw wood down under?

 

[Apprentice_GM]

Well after some thought I've concluded it might not be your chimney...mostly cause you'd smell smoke. To rule that out next time before starting a fire dissemble the stove pipe from the flue and mirror the chimney.

If the mirror reveals the chimney to be clear the next couple of 3 days start a conventional fire from the bottom up...the way cave men did it. Do that an note any difference.

I remember when you tore out that gorgeous inefficient fireplace of your...that took a lot of balls. I respect folks that can do that.

SavageActor7 and all, today I got the chance to pull the baffle out that creates the secondary ignition chamber, and take the flu cap / cowl off as well. The flu is clean and clear and the cowl / cap doesn't even have a screen (presume for spark arrest or preventing insects / birds in?) so all is good there.

I split 2 palings and MC on the outside was 16% - 18% and inside was 12% - 14% which surprised me given the usual MC is < 10% even in previously rainy / humid weather. Perhaps its a combination of those 2 things - higher MC than I usually have, despite being well under 20%, and some draft issues with the high humidity and low temp differentials between inside and outside the house (although I have had those things before perhaps not altogether and to the same extent).

Savage thanks for your kind words too

 

[Todd]

One other thing you may want to check is your air control mechanism. Something could of worked loose and it could be stuck on low. Maybe a mouse built a nest in there?

 

[carinya]

You are welcome to as many palings as you want

Have you visited Terrigal? It's 15 minutes from me (Glenning Valley).

You can't beat dessicated eucalyptus for a roaring fire :lol:

Grew up at Bronte but relo's had a place at Ettalong where I spent hol's. (This is back in the 50's-60's.....). As a kid, I remember fishing on the bridge at the Entrance and, of course, dropping my line in the water. :-S I have a niece at Bateau Bay but haven't seen her for 10years.

Hope you figure out your stove difficulties.