Everything Drolet Tundra - Heatmax...

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
Recent observation now that I'm running both tundra's a bit, both with serial #'s in the 1340's. The fan switch takes a lot more heat to run the fan on my 2nd install. So much so that the damper almost has to be open to have the fan come on. Once the furnace has settled into secondary burn with air inlet closed the fan shuts off after a bit and takes a long time to come back on plus the top of the furnace is getting much hotter than my other Tundra.

A quick IR check shows it's taking 20-30F more to get it to turn on. I've ordered a adjustable fan switch to resolve the issue.
 
Recent observation now that I'm running both tundra's a bit, both with serial #'s in the 1340's. The fan switch takes a lot more heat to run the fan on my 2nd install. So much so that the damper almost has to be open to have the fan come on. Once the furnace has settled into secondary burn with air inlet closed the fan shuts off after a bit and takes a long time to come back on plus the top of the furnace is getting much hotter than my other Tundra.

A quick IR check shows it's taking 20-30F more to get it to turn on. I've ordered a adjustable fan switch to resolve the issue.
And when the fan is not running...there is probably not much heating going on. If it weren't for the fact that my fan switch is in the back (original location for the early models) and it is an adjustable switch, I don't think my fan would run as much as it does...and my "no heat" situation would be even worse than it is.
Sounds like your situation likely is as simple as a funky switch.
Interesting how different two of these things can be. I set both mine and my sisters up as close to identical as I could, and hers will run circles around mine (for now ::-))
 
I think I am on to something. I made an adapter so that I could spin my 6" chimney brush with my drill (thanks for the idea @Builderml ) and cleaned the heck outta the HEs last night (killed a fully charged L-ion battery!) I thought I had it spic n span in there until I looked very carefully with a bright light. There is a thin and highly polished ;lol layer of baked on soot/creosote covering patches in all 3 HEs. It is about as thick as a heavy layer of paint (think old house paint) and to the "untrained" eye, it looks like bare metal. I confirmed it was not metal by hitting it with the torch...yep, it popcorned up like creosote does when heated real hot! This stuff is really hard and the chimney brush will be worn out before it all comes off. Scraping it off with a sharp edge works but is very time consuming and it is hard to reach much of it. I'm gonna wheel my oxy/acetylene torch in tonight and finish burning it off. I thought about spraying it with kerosene and just lighting it... but thought better of doing that, probably make a mini chimney fire !!!
I tried to get pics but the camera just didn't pic up what I was seeing in a way that shows up on the screen, sorry guys, gotta take my word on this one ::-)
Glad i could help, It did do a really nice job cleaning the inside of the HE. I think i am going to get an 8" poly brush and cut it down a hair so its nice and tight to fit into the center tube. Thanks for the inside "naked tundra" photos. Did you use a steel or poly brush on the inside of the HE? If steel did it scratch the walls?
 
Well, I drug the torch set into the basement tonight, and I think I won.
The buildup seemed to puff up pretty easily and sometimes just pop right off when heated. For anybody familiar with metal working, it was kinda like mill scale when heating new carbon steel. Anyways, things cleaned up pretty well when I ran the brush through afterwards. I could tell I was down to the bare metal because there was a very light layer of surface rust hiding under there. Dunno if this is gonna make any real difference or not, but it sure can't hurt!
I don't know what it is about using a oxy/acetylene torch in the house, but it kinda made me nervous. At one point the torch popped loudly and went out, the way rosebuds do when set low and used in a confined spot. The loud POP was kinda amplified inside the center HE and it scared the poo outta me! I wasn't thinking about the fact that I was putting a ton of heat into the HEs (#6 rosebud tip) and I wasn't paying attention to the ducts temps. I looked up at one point and seen 230* on my digital thermometer! !!! I jumped the fan switch out for the remainder of the job...
This was probably not a solution that I would recommend for most people to try at home (I do all my own stunts...at my own risk ;lol)
Too bad it is too warm to try this thing out tonight ;hm
If this doesn't work, then "plenums-are-us" here I come!
Did you use a steel or poly brush on the inside of the HE? If steel did it scratch the walls?
Steel, 'cause it was what I had. It just polished the walls like a wire wheel does on steel
 
Last edited:
  • Like
Reactions: STIHLY DAN
For some reason I was cold ( house was at 70F ) so I fired up the Caddy.

Plenum temps were bouncing between 132F - 134F
Register temps are 98F

Firebox was about one-third full and the secondaries were lit.

My fire will eventually go out also when I close the damper door all of the way. The high tech solution that I came up with is to use a small finishing nail to prop the damper door open. It seems to the perfect amount of air to keep the fire going and to not fire it too much.
 
@sloeffle , so these temps were with the furnace on "high fire"?
You are saying the fire goes out with the damper closed normally, or just during these warmer temps?
 
@brenndatomu, I rarely fill my firebox more than half full. I will call it a "medium fire". ;)My thought is that I can always add more wood but I can't take it out. Temps below 5F will give her a run for the money.

Never had luck in any weather conditions with keeping the fire going with the damper closed. Maybe I don't have enough draft. Hopefully that manometer I am getting from you will solve that mystery. Chimney is 20' or 24' tall class A double wall.
 
  • Like
Reactions: STIHLY DAN
@brenndatomu, I rarely fill my firebox more than half full. I will call it a "medium fire". ;)My thought is that I can always add more wood but I can't take it out. Temps below 5F will give her a run for the money.
The damper was open or closed when you were getting 98* at the registers?
 
Damper was open a 1/16th of an inch using the finish nail.

The fire will eventually go out if with the damper closed.
 
Well, I'm a couple fires in on my HE supercleaning. It definitely helped, I'm running ~8-10* higher in the duct 2' above the furnace. I'm not sure if it is really making a real difference as far as keeping the house warmer, it seems to have helped a little, maybe. Not enough time in the seat yet to know for sure. It is 71-72* in the house right now, I loaded ~1/2 a load last night at 11:30, and 31* for a low overnight. The fan is still cycling on/off right now (5 min on, 10 off) This goofy warm weather is making it tough for someone who is trying to methodically dial in his new wood furnace! ::-)
Oh, I moved the adjustable fan control switch to the "new" position last night too. I think that was a step in the right direction. The fan comes on sooner after a reload, and doesn't blow quite as much cool air at the end of the run.
I'll live with this current setup for a bit to get a good feel for it, but I have sneaking suspicion that I will be installing a supply plenum before this is all over...;)
 
Last edited:
  • Like
Reactions: STIHLY DAN
but I have sneaking suspicion that I will be installing a supply plenum before this is all over...;)

One of the contractors I had give me a quote wanted to do this. He claimed I'd be able to extract more heat from the unit. Makes sence but I'm no pro! I'd be really interested if you did this and heard what your results were.
 
One of the contractors I had give me a quote wanted to do this. He claimed I'd be able to extract more heat from the unit. Makes sence but I'm no pro! I'd be really interested if you did this and heard what your results were.
It does make sense, there is a lot of heat radiating off of that top, especially toward the front outlet. I would probably uncover it also if I do a plenum, so it would be the two side and the front outlets open, for a total of 3.
I did a plenum on my sisters Tundra, it seems to be working good for them.
 
Last edited:
Just for future reference I have found that this stuff actualy works pretty well to soften hard creosote but it takes some time of use for it to do it's work.

Disclaimer: I have no association with Rutland nor do I benifet for the sale of this product in any way.
 

Attachments

  • P0002_051215.jpg
    P0002_051215.jpg
    140.5 KB · Views: 228
Brenn, just to let you know once my fan comes on it stays on the whole burn. None of the 5 on/ 10 off stuff, the only time its does start to cycle is at the end when it just has some coals left.
 
  • Like
Reactions: KARB2014
Brenn, just to let you know once my fan comes on it stays on the whole burn. None of the 5 on/ 10 off stuff, the only time its does start to cycle is at the end when it just has some coals left.
Yep same here, cycles at the end. I was over 9 hrs into the load when I posted that about the "5 on 10 off" thing.
I appreciate everybodys help here with posting their "stats" and everything. After running all weekend I do believe I have made progress. It is keeping the house warm...BUT, it is also not that cold out, so, if winter ever comes, we shall see >>
 
  • Like
Reactions: KARB2014
It's been to warm here to run the Tundra much, but now just as I feared...the temp finally dropped outside and so did the inside temp too. She's just not keepin up. Low 20s overnight and I wake to 68-69 in the house this AM. Anything under 70 is too cold around here. And I don't do all this work makin firewood to be cold.
So yesterday I added a third duct connection, from the front hole. So I am using the two side holes and now the front one too.
Comparing the temps externally about 2' above the furnace, the front pipe runs about 10* hotter than the other two. We'll see how this does. I thought I'd try this before installing an actual plenum, I was planning at least 3 pipes between the plenum and the main duct anyways. I have the 24" x 24" plenum that came with my Yukon that I never used...looks like a good candidate to me...after a few mods. It is 36" tall so it would need to be cut down a bit.
One step at a time
 
Interesting to see how she works with the third duct. Has that played havic on your static pressure at all? I too wake up to 67-69 if its cold at night. Cold being mid 20's and down. I am good with that as i know the Tundra is undersized for my application. I load at about 8-9pm before heading to bed. If i was to get up around 1am to put some more wood on that would be ideal and would keep the house in the low 70's.

So i have been doing some experimenting with the tundra over the last few weeks. I'll brake it down into 3 "test"
Method # 1 - I load the firebox full as i can get it and let the load get nice and hot, usually i'll let it bounce off the high limit a couple times at which point i will shut the damper down and just let her go into secondary mode.
Method #1 result- Nice long burn times 6 hours plus, I have made it overnight with a few coals still in the morning. But not much heat coming out at the end. For me i think this will work best for when the temps will be mid 30's plus. Will keep house temp at 69-73 depending on outside temps.

Method # 2- I load firebox full let the load get nice and hot. By now my coffee is done and i head upstairs for a refill and turn the old style round thermostat to about 2* above what the current temp is on the thermostat. What i have noticed doing this and what i really like is i am able to bring the temp up fairly quick and still have a decent burn time. about 4-6 hours. The result of setting the round dial t-stat 2* higher is it cycles about 5min. damper open and about 5 min. damper closed for about the first hour, increasing my burn times with saving the wood while keeping real hot secondary burns. As the temp rises it just keeps the damper closed further increasing my burn time.
Method #2 result- Increased burn times. Bring up temp fairly quickly. I think this method will be best for most temps from teen's and 20's. So far this is my method of choice.
Here is a picture of how i have my t-stat's set up. The round for wood and digital for oil. You can see current temp in house is 71* with the oil furnace set at 67* as back up. By the way i am about 5 hours into this burn. The round dial temps are not accurate as you can see.
KIMG0429.jpeg
Method #3 - I load firebox full and just let her go wide open, She bounces off the high limit most of the time for the first hour.
Method #3- Result crappy burn times 2-4 hours, Able to bring temp up faster but in all honesty i don't think it does it that much faster compared to method #2. I suspect i'll have to do this if temps drop below 10*. We shall see as i have not had temps below 20* so far.

Sorry for the long post but just wanted to give an idea of what i am doing in the short experience i have with the Tundra. As a side note when i heat with oil as in the past i keep the tstat set at 69*. So 71*is pretty warm for us. The digital Tstat may actually be off a touch because at 71* i can tell you its plenty warm. When i had the house up to 73* the wife had opened the windows. Also keep in mind these results are from burning softwood only mostly spruce/pine. I have been waiting for the temps to come down before i start burning the hardwood. I suspect i should be able to increase my burn times by about 1-2 hours. Hope this helps some others.
Merry Christmas and Happy New Years !!!!!!!!!
 
Last edited:
That false top has to be effecting the overall output of the furnace. Either that, or your home isn't as tight as you think. I dealt with the same thing when I got our Caddy. The old furnace would cook us out and I assumed the house was tight because of it. I upgraded and found the house was extremely loose. I had pretty much the exact results. Fast forward, I went 11 hours between loads overnight and the house kept above 73 overnight with temps in the mid 20's. We coast on coals for quite some time. I'll also add, you shouldn't need a huge flaming firebox for a clean burn. If we open the damper too long, it does affect burntimes.
 
  • Like
Reactions: STIHLY DAN
Interesting to see how she works with the third duct. Has that played havic on your static pressure at all?
No, I have each one dampered individually so after a round or two of adjusting, I can get them all the same.
That false top has to be effecting the overall output of the furnace.
I agree.
Either that, or your home isn't as tight as you think
If you are referring to me then, maybe, but back before I upgraded the insulation I only had to use ~700ish gallons of oil per winter. And that was with an old 1940 coal-burner-converted-to-oil furnace. The other thing is that my Yukon is rated the same as the Tundra for output (140k gross) and it will heat us right outta here on the same or, really, I think maybe less wood that what I have been using. But to be honest, when I say "less" wood, I have to admit that is after I modded the Yook for a cleaner burn.
We coast on coals for quite some time
Yah...ain't happening with the Tundra...very little heat output with coals, unless it is a firebox completely full of red screaming hot coals...and even then the fan cycles a good bit. The furnace room stays nice and warm though...80!? Feels cold when I go back upstairs ;lol

I agree with what others have said about the rating of the Tundra...way to high. The only way it is gonna heat 2500 sq ft is if you have a "super-insulated" home, or live a good bit further south than Ohio.

For any of you that are members over on AS, remember a couple years ago when Spidey put that "EPA furnace" in and then froze all winter...yeah, I'm seeing what he was talking about here. Like him though, I won't give up on this until the horse is long dead and beat thoroughly! Theres got to be a way to get this thing to heat the house. I love the clean burn and the user friendly-ness of the Tundra...just need it to act like a furnace now!
 
  • Like
Reactions: KARB2014
140,000 btus is an input rating, I believe it's around 90,000 btu high output, and around 60,000 average output. Even then, there's a curve and these numbers drop after so many hours. Just out of curiosity, I wonder how the new usstove furnaces output compares, being a similar setup. Luckily so far this winter had been nothing like the last, or you'd be in trouble. I'm rootin for you, but it sounds like you're running out of options.
 
;lol
I agree with what others have said about the rating of the Tundra...way to high. The only way it is gonna heat 2500 sq ft is if you have a "super-insulated" home, or live a good bit further south than Ohio.
OK let me give you the specs of what I have going on.
2800sqft total living space,
Tundra ducted to about 2000 sq ft, remaining 800 sqft is still being heated but no ducts to those rooms, really aren't any cold spots in the house with the doors left open to those rooms,
2x4 walls with 1" air seal done with closed cell spray foam, r13 batts over spray foam, yes insulation is compressed some, blown in attic insulation about 18-20 inches worth,
Ceiling heights are 10' minimum, 650 sq ft at 14' high, 150 sq ft at 12' , large windows and doors so alot of glass area as well. I am sure most of my heat is at the ceiling. When I get on the ladder and change a bulb you can really tell where the heat is. Right now its 30* outside 70* in the house and I just came down stairs, blower just turned off so you know I am down to just a few coals.
I wouldn't say my house is super insulated but Tundra is doing to job, I don't see how at 2500 sqft with 8'/9' ceilings and OK insulation the tundra wouldn't do it. To give you another example the past two years I used 1500gallons of oil each year. During the cold months it was exaclty 300 gallons on month. So you know now why I am trying wood.
 
Either that, or your home isn't as tight as you think
I need to get my paws on one of those infra-red cameras one of these days...I'm sure there are improvements to be had here
140,000 btus is an input rating, I believe it's around 90,000 btu high output, and around 60,000 average output.
Wow, is it that low? The Yook is 140k in and 112k out...at least what they claim. It does have a HUGE heat exchanger...54 sq ft total! That is why the furnace is so darn big (that's it in my avatar pic)
Luckily so far this winter had been nothing like the last, or you'd be in trouble. I'm rootin for you, but it sounds like you're running out of options.
Nah...I got an ace-in-the-hole...if it gets too cold, flip the switch on the Yukon, BAM, heat! ::-)
To give you another example the past two years I used 1500gallons of oil each year. During the cold months it was exaclty 300 gallons on month
Right, you just made my point. I used half that oil...BEFORE insulation upgrades, and your Tundra is keepin up fine, mine not so much
 
Brenn are you sure the controls you have on are not hurting you at all?
 
Brenn are you sure the controls you have on are not hurting you at all?
Nah, results before were even worse...I have been making some slow gains...besides I have tried all kind of different settings, to no avail...even not using it