Introducing Brand New Wood Furnace to Market - The Drolet Tundra!

[Flamingfire]

Thanks

 

[Flamingfire]

I also have a drolet austral in a trailer with outside air but I only have about 10' of chimney do I need more for the right amount of draft?

 

[brenndatomu]

Probably. 15' chimney is considered minimum for most modern stoves

 

[byron2]

Hi everyone new poster here......I have a Heatmax dfo1000 wood furnace...From what I've read in this thread its the same as the Tundra I picked it up Sept of 2014. I see you were talking about the thermodisc that runs the blower... Like some here have said it takes quite awhile to get the blower to kick in and then it doesn't stay on for long at all....The one I have is a F120-10F....Anyway I went to the droplet site and looked at the latest online manual and its different than mine its shows the thermodisc as F110-20F.... My thinking is this would be much better...my question is this It looks as if they have changed the location from the back in the control box to the top of the stove near the high limit thermodisc ...Wondering if anyone knows....I want to do something maybe I should just get an adjustable one .... thoughts would be much appreciated ...... I'm also having trouble with coaling which is my only gripe about this furnace fiddling with it to much to get the coals burned down

 

[spadjen]

Having problems with excessive coals and no heat at the end of the cycle. The coal bed in the pic is a lot smaller then usual, more then likely due to some changes that I have made. I find the wood turns to coals rather fast? about 3 hours in to the cycle it turns to all coals if half loaded. This happens even with the damper completely shut. I had an EPA drolet ht-2000, and never had any issues. I have made some adjustments to my heatmax to bring things into spec.

Stove located in a basement
1500 sq foot 1.5 story house , with air infiltration problems.
I have 9 heat registers that are 3"x8"
Cold air return that is supplied by two 8" rounds, with filter.
16' of duravent all outside.
approximately 6' of black stove pipe with very little pitch (see pics)
one 90 degree T on the outside and two 45's on the inside.
Using a wall thermostat.
10 month seasoned wood that is 16-22%
A wireless digital prob thermometer.

I have covered all my heat resisters with foil, leaving only 1-2" for an opening. I have installed a damper in one of my lines. This increased my static pressure for my duct work from .08 to .24. note that when I remove the cover to my cold air intake to reduce restriction I can get .4 more pressure in my duct work. I have changed my fan speed to medium low. I replaced the fan snap disk with an adjustable one. I since adjusted it to 120 degrees to simulate factory settings until I can figure out what the issues are. The only difference with the adjustable is the 20 degree swing vs 10. I have removed my chimney cap, and measured my draft at .04 with damper closed by firebox hot, and .05-.06 with damper open. Outside temperatures have been -5 to 15 degrees at night and 5-20 during the day.

I am thinking that my stove pipe in the house is a little too long and the pitch is not helping. This is especially true with the minimum 16' chimney height. However, The draft readings are in spec. The excessive coals I would assume to be not enough air into the firebox or the firebox cooling down too much? I have fixed that static pressure, the fan speed, and snapdisk to keep the firebox hot. Internal stove pipe temperatures are 550 degrees with it fully running and 325-400 with the damper closed. I was told yesterday that internal should not drop below 500 with the damper closed and should run 500-800/900 during normal operation. I have 2 more 36" sections of chimney I can add to make 22', but from the pics you can see that would not be easy. There would be about 10' chimney above the eave. Changing the location of the stove inside would be hard to do since it involves the water heater, cold air return, and plenum.

Any recommendations on what might be going on or what to try?

 

[brenndatomu]

How long have you have this unit? Has it worked good for you up 'til now?
Hard to tell for sure from a pic but from the looks of those unburnt black chunks, your wood is not as dry as you think. If you are checking with a meter, what was the procedure? Even done properly, moisture meters aren't always 100% accurate
I'd say your stove pipe/chimney are fine.
Have you verified "zero" on your manometer lately?

 

[spadjen]

How long have you have this unit? Has it worked good for you up 'til now?
Hard to tell for sure from a pic but from the looks of those unburnt black chunks, your wood is not as dry as you think. If you are checking with a meter, what was the procedure? Even done properly, moisture meters aren't always 100% accurate
I'd say your stove pipe/chimney are fine.
Have you verified "zero" on your manometer lately?

Have had this one for 2 months. Had same furnace last year too. Had similar problems but not as bad. Maybe it is worse when it is colder outside? The unburned chunks is from an attempt to burn down the coals. Usually it is just a thick blank of glowing red hot coals. When checking the wood i checked the ends and middle. Did not bother measuring the pieces on the outside of the wood pile. I got a range of readings but the majority was in the range I quoted. How do you verify zero? I do reset the unit and zero it out with every reading.

 

[laynes69]

Having had this firebox for 5 years or so now, your main problem is draft. Things will run well when there's fuel in the furnace and flue temps are up. It's when the furnace reaches the coaling stage or before, flue temps can drop below 150 degrees. At this point with a 16' chimney with 2-90° elbows, you can't produce enough draft to burn down the coals, leaving you with what you have now. Those elbows with that length of chimney reduces draft to basically nothing. Since you have a manometer, when you hit that stage test it. If draft falls below .04" anywhere in the burn, you don't have enough draft. The wood may be okay, but 22% is on the higher side for the furnace. It will burn and produce heat, just not as well as it should. With the length of your single wall, that area alone loses alot of heat. Adding a section or two of chimney or double wall flue pipe should bring your draft levels up, therefore performance will increase.

 

[brenndatomu]

Have had this one for 2 months. Had same furnace last year too.

You move?

Maybe it is worse when it is colder outside?

Sounds like it. Some people with EPA type stoves are complaining of the same thing

When checking the wood i checked the ends and middle.

You should be checking the inside right after making a fresh split. The middle is usually a bit wetter than the ends

How do you verify zero?

Just uplug from the flue, make sure it drops to zero

 

[spadjen]

Having had this firebox for 5 years or so now, your main problem is draft. Things will run well when there's fuel in the furnace and flue temps are up. It's when the furnace reaches the coaling stage or before, flue temps can drop below 150 degrees. At this point with a 16' chimney with 2-90° elbows, you can't produce enough draft to burn down the coals, leaving you with what you have now. Those elbows with that length of chimney reduces draft to basically nothing. Since you have a manometer, when you hit that stage test it. If draft falls below .04" anywhere in the burn, you don't have enough draft. The wood may be okay, but 22% is on the higher side for the furnace. It will burn and produce heat, just not as well as it should. With the length of your single wall, that area alone loses alot of heat. Adding a section or two of chimney or double wall flue pipe should bring your draft levels up, therefore performance will increase.

Measured it last night when the firebox was shut down for awhile. It measured .03 but does go to .04 when you open it up for maybe 15 mins. good point on the double wall. I completely overlooked that option for some reason. I do have 6 more feet of chimney but not sure how to reach since it is 6' past the eave now.

 

[spadjen]

You move?


Sounds like it. Some people with EPA type stoves are complaining of the same thing


You should be checking the inside right after making a fresh split. The middle is usually a bit wetter than the ends


Just uplug from the flue, make sure it drops to zero

I dont have anything to split the wood with since I am not allowed around sharp objects. I cause too much self injury...lol. The manometer I have does not permanently attach so it is not attached to the flue. I just drill a hole and put the rubber tube in. But when I retest I do reset the meter to zero by the internal self calibration. I would assume that I am getting good readings from it.

I did not move. Had an issue with my old one and it has been replaced with the one I have now. I had one of the first production units.

 

[laynes69]

I take it, your not getting enough heat from the coalbed? If so ideally you will load in cycles, once the coalbed has burnt down, reload, repeat. Our home is 2500 sqft, 2 story with 10' ceilings plus basement which is 1200 sqft. Last night it dropped to -5° (chills around -20) we loaded at 9:30pm it was 73, at 4:30am it was 70 with a nice hot coalbed.

Your draft is low, but not as bad as what I would have thought. I would go double wall pipe with that length of run to the chimney. That should make a big difference with draft. With your wood, get ahead. We burn 18+ month wood and it makes a big difference.

Air infiltration problems in a home will compound the problem. This weather will find the weakness in any home. On the otherhand, this weather makes it easy to find those drafts. Buy a case of caulking and a few cans of expanding foam. Start in your attic, and plug every gap you find in the attic floor. Look at top plates, electrical wires, junction boxes, plumbing, interior partition walls and anything else you can find. Seal those gaps, then move to the basement. Look around your foundation, sill plates, etc. Then move into the living space and seal any gaps at the floors, around windows and doors, etc. It's a dirty job, takes some time, but doesn't cost much. You do this, and you'll feel like you have a new wood furnace. When I bought our furnace, I couldn't keep the house at 68 when it was 25°, now it's below zero and the house is 72. We also have 42 windows. Even before we added attic insulation, when we air sealed our attic our heating demand dropped probably 20-30%. In our case, I found 32 open cavities in our attic that had fiberglass stuffed in them and covered in cellulose. We had the equivalent of a 6' diameter hole in our attic, shocking.

 

[spadjen]

I take it, your not getting enough heat from the coalbed? If so ideally you will load in cycles, once the coalbed has burnt down, reload, repeat. Our home is 2500 sqft, 2 story with 10' ceilings plus basement which is 1200 sqft. Last night it dropped to -5° (chills around -20) we loaded at 9:30pm it was 73, at 4:30am it was 70 with a nice hot coalbed.

Your draft is low, but not as bad as what I would have thought. I would go double wall pipe with that length of run to the chimney. That should make a big difference with draft. With your wood, get ahead. We burn 18+ month wood and it makes a big difference.

Air infiltration problems in a home will compound the problem. This weather will find the weakness in any home. On the otherhand, this weather makes it easy to find those drafts. Buy a case of caulking and a few cans of expanding foam. Start in your attic, and plug every gap you find in the attic floor. Look at top plates, electrical wires, junction boxes, plumbing, interior partition walls and anything else you can find. Seal those gaps, then move to the basement. Look around your foundation, sill plates, etc. Then move into the living space and seal any gaps at the floors, around windows and doors, etc. It's a dirty job, takes some time, but doesn't cost much. You do this, and you'll feel like you have a new wood furnace. When I bought our furnace, I couldn't keep the house at 68 when it was 25°, now it's below zero and the house is 72. We also have 42 windows. Even before we added attic insulation, when we air sealed our attic our heating demand dropped probably 20-30%. In our case, I found 32 open cavities in our attic that had fiberglass stuffed in them and covered in cellulose. We had the equivalent of a 6' diameter hole in our attic, shocking.

The problem I found was that the coal bead is very thick even when I start with an empty stove. At that point the house is dropping temperature and the furnace fan will not kick in. However, now that I increased the static pressure it seems the fan is turning on more when there is a coal bed. I am wondering if I am filling the firebox too much? Even with the air infiltration problems, at 1500 sq feet, the house is on the smaller side for the furnace.

So I should add double wall instead of chimney length? It would be a much easier install, but I dont have double wall and would need to order it.

The air infiltration problems I have are a little more involved. I do have have the normal foaming and calking of gaps. I need to replace both exterior doors, which wont happen this year. They need to be custom made due to the rough opening size. At the top of the walls and between the beams (post and beam house) there is insulation that when you pull it back, goes right out side. I am in the process of sheet rocking this area to make it air tight. This should help a lot.

 

[laynes69]

If you want heat before loading, pull the coals forward and open the damper. You can also place a softer wood split across the top and the coals will burn down while producing alot of heat. If it's extremely cold, we will do that once or twice then level the coalbed and load. If we let the load go and don't touch it, at the end of the burn we have ash up front and coals in the back. Before spending money on double wall pipe, try 1 section on your chimney if you can, since you have it. Extra draft during the coaling stage will keep those coals remain hot and burn them down. Instead of smaller loads, have you tried full loads?

 

[spadjen]

I do pull the coals forward. Not enough heat even with a 10" bed of coal. When trying to burn down with a piece of wood across the top, I get heat but the wood turns to coals fast and just adds to the coal bed. Or at least I dont see it getting much smaller after a few times. This is what lead me to the drafting issue?

Normally on an overnight burn I must so much wood in that its filled to the tubes. I am wondering if that would be too full for this size house? Damper keeps closing too often for the wood load to burn? This would cause a bad draft on a system that had low draft. I am assuming anyway.


I was thinking of finding a craigslist specialist to get up on the roof and put the 2 pieces of chimney together. LOL. I dont have a roof support bracket. Not sure I can get by with one until the end of the season? Would be about 12' unsupported. Depending on shipping speed, I can wait to have everything installed together.

 

[laynes69]

Was your draft reading at .03" taken when the furnace was at the coaling stage, or taken when the damper was closed and secondaries firing? As far as loading, I wouldn't load full loads if not needed.

 

[Cpeder]

I'm having the same problem burning red oak. The maple did not do leave more then a 2" coal bed. Right now I'm about 6-8" of bright red hot coals. I set the thermostat up to open the damper. This burns it down but if I don't do this early enough there won't be enough room for a new load before bed. Of corse adding wood every 3 hours will only compound the problem. I don't get much heat in the early morning hours from the coal bed. My thought is to change the thermodisc. My Manuel say its 140 on 120 off. Having an adjustable set at 130 on and 100 off should allow fans to cycle longer and when just coals turn on sooner. Any heat that can be used is good heat in my book.

 

[flotek]

This can happen when weather gets really cold . You have a few things that cause this :

Your adding wood too frequently on top of the coals before the cycle is complete

Your not running the air flap long enough to burn off the coals you do have

Your packing dense wood that is known to really coal up

There's tons of heat in that bed of coals ..you just need to get air to it to burn them off . I open up the air control by means of cranking up t stat and then crack the firebox door and it will glow a couple thin slabs on that bed helps get things rocking too ..throwing great heat for hours on end . Of coarse not everyone is going to be comfortable un securing the door for safety reasons

 

[Grey Ghost]

I've had that problem too but I was burning big hunks of wood with the old idea of big "over nighters". I switched to smaller splits and I get a nice coal bed that heats for quite awhile and when the cycle is complete, there's some coals in the back, ashes in the front. I scoop out some ashes, level out the coals and throw some more wood in.

Smaller splits worked well for me. Also, if you aren't using dry wood, it's gonna create a thick coal bed that doesn't really put out heat. I've got a friend that has logs stacked for years but he doesn't cut, split and stack until right before winter. Then he throws it directly in his basement. He can't figure out why his furnace doesn't heat well. His moisture readings are always way high although the logs have been stacked for years.

I cut, split and stack outside under an open wood shed for at least a year. Works well and doesn't coal up like that. Using smaller splits will help if you have slightly moust wood too. Not saying that is the problem but it could be. Just sharing my experience with this stove.

 

[spadjen]

Was your draft reading at .03" taken when the furnace was at the coaling stage, or taken when the damper was closed and secondaries firing? As far as loading, I wouldn't load full loads if not needed.

that was with warm coals and the damper shut.

I'm having the same problem burning red oak. The maple did not do leave more then a 2" coal bed. Right now I'm about 6-8" of bright red hot coals. I set the thermostat up to open the damper. This burns it down but if I don't do this early enough there won't be enough room for a new load before bed. Of corse adding wood every 3 hours will only compound the problem. I don't get much heat in the early morning hours from the coal bed. My thought is to change the thermodisc. My Manuel say its 140 on 120 off. Having an adjustable set at 130 on and 100 off should allow fans to cycle longer and when just coals turn on sooner. Any heat that can be used is good heat in my book.

I did change the snap disk to adjustable. I now have it set at 115 and get much more heat from the furnace when it is shut down. Not sure what type of wood I have other then its hard wood. No ash, very little birch.

This can happen when weather gets really cold . You have a few things that cause this :

Your adding wood too frequently on top of the coals before the cycle is complete

Your not running the air flap long enough to burn off the coals you do have

Your packing dense wood that is known to really coal up

There's tons of heat in that bed of coals ..you just need to get air to it to burn them off . I open up the air control by means of cranking up t stat and then crack the firebox door and it will glow a couple thin slabs on that bed helps get things rocking too ..throwing great heat for hours on end . Of coarse not everyone is going to be comfortable un securing the door for safety reasons

Still happens when a new load is put in an empty stove. Did this to eliminate the possibility of a frequent load cycle. I have had to do that before for an extended burn when no one will be home, but the cycle has not compleated. Not the case here though.

The coal bed still wont burn down with the flap open. Well it prob will, but after 2 hours it was still almost the same size.

Not sure what type of wood I have, so this could be a possibility.

Have tried burning down the coals like that. Still has not worked out for the most part. I do get a lot more combustion with the door partly open. I wonder if this is also a sign of poor draft? I have not tried leaving the door cracked with a large coal bed and wonder if I should try that. If it was to work, then I would assume that meant that there was not enough air into the fire box.

I've had that problem too but I was burning big hunks of wood with the old idea of big "over nighters". I switched to smaller splits and I get a nice coal bed that heats for quite awhile and when the cycle is complete, there's some coals in the back, ashes in the front. I scoop out some ashes, level out the coals and throw some more wood in.

Smaller splits worked well for me. Also, if you aren't using dry wood, it's gonna create a thick coal bed that doesn't really put out heat. I've got a friend that has logs stacked for years but he doesn't cut, split and stack until right before winter. Then he throws it directly in his basement. He can't figure out why his furnace doesn't heat well. His moisture readings are always way high although the logs have been stacked for years.

I cut, split and stack outside under an open wood shed for at least a year. Works well and doesn't coal up like that. Using smaller splits will help if you have slightly moust wood too. Not saying that is the problem but it could be. Just sharing my experience with this stove.

I had the same problem with big split. I went with the same thought as you, the bigger the better for longer burns. I since switch to smaller splits and have had better results. Smaller also drys faster. Wood has been seasoning for 10 months under a roof and open on the sides. according to the meter, it is in spec. I might try ordering ash for next year since it drys faster.