Everything Drolet Tundra - Heatmax...

[jdogg]

Every one would like a new car (or truck) but some times it's not in the budget so you have to buy a used one or two for less money to get you by until your situation allows you to buy brand new. Yes, you may spend a little more in the long run but at least you never have to walk

I def want something that will last longer than 5 yrs way to much work to get a new one in basement and remove old one.
Im def holding off on the drolet till they get it right. I'll let you "early adaptors" deal with their design flaws. Kinda like my vette they made C-4s from 1984-1996 the latest model has the most powerfull motor (fastest) and least design issues. Like my 1992 was the first year for the LT-1 engine, first one over 300 HP stock and a upgrade over previous models.
But they put the opti spark (basicly the distributor) on the front of the engine below the waterpump. Not a good idea when the waterpump starts going it leaks coolent on your distributor. (Not good) etc prob solved by 1996 etc.

 

[jdogg]

So last year when my waterpump went out I installed a new opti-spark at the same time. The old one still worked but when I opened it up it was full of corrosion. Once you have the water pump out the opti is the next thing down so I said "change it while its easy to do.

 

[JRHAWK9]

So last year when my waterpump went out I installed a new opti-spark at the same time. The old one still worked but when I opened it up it was full of corrosion. Once you have the water pump out the opti is the next thing down so I said "change it while its easy to do.

ahhh, good ole opti-crap. The LT1's were also put in f-bodies from '93-'97. The '96 LT4 found in the Vette of that year also had it. The LT1's were also put in the b bodies. I have an LS1 fbody and a LS3 Vette, so I was never blessed with the opti-crap. My GF used to have a '95 TA convert though which had the LT1. It never gave her any problems though. BTW, it's LT1 (without the hyphen). The LT-1 was the RPO code for the Gen I small block used in the early 70's. The current LT1 is now the RPO for the gen V small block used in the new C7.

Anyway, back on track. I would agree with you waiting till they get things figured out, It's almost like they are following Microsoft's way of doing things when they released Vista. Using the public as guinea pigs in order to evaluate and then release an updated version with all the fixes.

 

[jdogg]

Well the Tundra is back on Menards 11% off plus sale price of $1399 vrs list price of $1799. So after you get your in-store credit rebate check thats works out to $1245.99. What a killer deal!

https://www.menards.com/main/p-2431486-c-12809.htm

 

[jdogg]

You know the blower only circulates air around the sides and top of the firebox front and back your on your own. They prob didn't use thick enough steel in the front. I'd prob try to seal the crack with stove cement or gasket cement and get a piece of say firebrick or ceramic in front of where the crack started. Prob try to glue the firebrick in with stove cement or something similar. Will need clean shiney metal on inside of the firebox for it to have a chance of working. Don't let your furnace run hot, if its not enough heat when its below zero, let the regular furnace run for 15 minutes or so. Better than it running all day and night like a non wood burning home. Remember if your furnace keeps you toasty when its 30 below its gonna cook you out the house when its 30 above.

 

[3fordasho]

Here are most of the details for my Tundra add on control:
Temp control is a Omega engineering #CN418V-R1-R2
J-type thermocouple - Mcmaster 3871K52

Later tonight I'll scroll through all the settings for the Omega temp control and post those up too.

 

[Buzz Saw]

What's the orange stuff on the stove pipe?

 

[3fordasho]

Hi temp silicon - had some reverse draft issues when first installed that have since been corrected (other open vents up through the roof in the furnace room - now closed off) Supposed to be good to 900F and have not had problems with it getting too hot but I'll probably pull it off at some point. It did reduce the smoke spillage when I was having the draft issues.

 

[brenndatomu]

J-type thermocouple - Mcmaster 3871K52

Have you had issues with the thermocouple getting fouled up by creosote/soot? How often do you have to pull the thermocouple out to clean it?

 

[3fordasho]

Have you had issues with the thermocouple getting fouled up by creosote/soot? How often do you have to pull the thermocouple out to clean it?

I have not cleaned it since installed late last year. It's working like it always did but I'm sure it's getting some build up just like my probe type thermometers do. They seem unaffected by some build up - maybe the response is slowed some? I typically will clean the probe thermometers once a year and will do the same with the thermocouple.

 

[TheBigIron]

Here are most of the details for my Tundra add on control:
Temp control is a Omega engineering #CN418V-R1-R2
J-type thermocouple - Mcmaster 3871K52

Later tonight I'll scroll through all the settings for the Omega temp control and post those up too.

Did that white box come with your temp monitor? I just received mine in the mail and did not receive that white box, just the control.

Thanks Dave

 

[brenndatomu]

Did that white box come with your temp monitor? I just received mine in the mail and did not receive that white box, just the control.

Thanks Dave

These type of controls are considered panel mount, so you will either need to cut a hole in a piece of sheet metal and then mount that somewheres or if you want it completely enclosed then you'll need to get some type of metal box like 3fords to mount it in. I suppose it could be as simple as a duplex receptacle box (4x4) with a couple box extenders on it...then get a blank cover, cut the proper size hole...wah-lah! Not quite as purty as 3fords though...

 

[3fordasho]

Did that white box come with your temp monitor? I just received mine in the mail and did not receive that white box, just the control.

Thanks Dave

It's a small electrical enclosure from Mcmaster- less than $20 if I recall correctly. Aprox 6" cube with plenty of knock-outs around the back.

 

[DoubleB]

either need to cut a hole in a piece of sheet metal and then mount that somewheres or if you want it completely enclosed then you'll need to get some type of metal box

If that's the case, I'd consider mounting it in one of the 2 sheet metal plates that were included to block off the blower box. It would be mounted rather low unfortunately, and not pointed forward, but at least something to consider. No extra parts required, everything is contained within what is already an enclosed electrical space, and you also have a spare and large access panel to get at the backside of the controller. Just a thought...

 

[3fordasho]

Electrical box that I used:
http://www.mcmaster.com/#75065k35/=wjbfxb

Mcmaster 75065K35

 

[DoubleB]

As for the cracking on my Tundra, I was surprised to notice that the crack closes with a fire (first picture) and opens when the furnace is cold (second picture).




I also notice that this crack (and I think most of the others I’ve seen here) is mostly horizontal. I also have spent quite a bit of time with the IR laser thermometer mapping out the front of the furnace, and found that the region of 2-3” wide along each side of the door is about 200F-300F hotter than the regions further to the side, and can get hotter than 750F with just a few minutes of the thermostat opening the damper. This temperature difference makes sense since the firebox is a couple inches wider than the door on each side, and there is no firebrick separating the firebox from the front of the furnace.

Given all this, it seems to me that the cause of the cracks (at least those around the door) is that the 2-3” wide regions of front surface on either side of the door must get hotter than the neighboring material enough to put it in compression during a fire. If those regions are hot enough the strength of the steel also starts to soften, evidently to the point that it permanently yields a bit so that once the furnace cools down, now the sides of the door are in tension. This must be happening enough that a combination of tension plus number of cycles may be what’s causing the cracks. At least that’s my theory.

Maybe this was already obvious to others. Or maybe the cause doesn’t completely matter. I just like to have a theory to help me take a guess at if I can fix it, or otherwise mitigate it, or know if SBI fixed it, or if I should avoid SBI products, or prefer them, or what.

My plan at the moment is to drill a hole at the root of this crack, add firebrick to the front sides of the door, and add over-temp protection to override the damper. But I’ll have to wait until next winter to see if this crack (or my other smaller cracks) grow.

At least these are easy things to do compared to replacing the furnace, which I may do after the foreseeable future.

 

[brenndatomu]

My plan at the moment is to drill a hole at the root of this crack, add firebrick to the front sides of the door, and add over-temp protection to override the damper

Exactly what I was planning on my sisters new Tundra (firebrick and temp control that is)
Nice job on the "homework" there Dubba!
I am gonna get a chance to play with one of these myself. I just acquired a HeatMax that was warrantied for cracking. I'm planning to weld it up just as you mentioned. I talked to one of the high pressure steam certified boiler welders at work about how to go about welding it, he seemed to think that a cold firebox would be OK, but I wonder which would be better...cold? Blazing hot? Warm? After seeing the difference in your cracks from cold to hot, it makes me think that the metal temp before/during welding does matter.

 

[DoubleB]

Nice score on the Heatmax! Is it for tinkering, or has the Yukon seen its last season?

Actually, I'm not planning on welding mine yet. I think I'll put some cement or silicone or something over the drilled hole/cracks, and see how it does with just that before I take the next step of welding. I have welded many pieces of steel together before, but I'm no pro and I don't have my own welder at the moment so I figure I'll wait to pay a guy to come until I know it's needed.

Another reason I'll probably wait to weld is so that I can have time next season to map out front face temperatures before and after I install the extra firebrick. I think the (assumed) change in temperature profile with and without the brick will help show what might happen for stresses with the firebrick installed. And, that might show whether you want to weld hot or cold

If I welded it, I'm guessing I'd do it cold (or maybe slightly warm if that helps lay a good bead). I'll simplify and pretend our furnaces are now unstressed both hot or cold since the crack opens/closes. I think I'd rather have the steel welded in a position unstressed cold and go to compression during a fire, then be welded in a position unstressed during a fire and go to tension after the fire. And ultimately tension causes cracks, not compression. Of course, too much compression is what I imagine leads to the deformation that leads to tension and the cracking we have, but hopefully the firebrick will mitigate the deformation and tension.

Another reason I'd lean toward welding it cold/warm is in case you want to tackle anything or lay a bead on the inside of the furnace, that option would be available.

Just my thoughts but they frequently change...

 

[brenndatomu]

Is it for tinkering, or has the Yukon seen its last season?

Well, some tinkering for sure, and the Yook will just be used for it's oil burner when we go away, unless the Drolet doesn't work out, then I will just continue to use the Yook full time until I decide what I'm gonna do long term.
Good idea on the silicone, drill a hole to stop the crack, seal it, then let it move around as it wants. Lots of things out there built like that, let it flex so it don't crack

 

[clayh88]

Hey guys. I'm new here.Been reading a lot but haven't posted much yet. Ive read about everything from this website on the tundra because I own one and have struggled with it. I have also experienced the cracks that a lot of guys are having problems with. SN 13XX. So the problem is on later units too. When i first started looking for a furnace I got some info from some guys that where using the tundra that had good things to say so i bought one. Wish I would have researched more and got the max caddy but funds did not allow. Long story short it has served me well in certain ways but drives me nuts most of the time. It cut my electric bills in half and but has developed cracks after one season and I have really struggled with learning this furnace. I believe my biggest problem is wet wood but other days I think there's something else. As far as the cracks SBI has been good to me for the most part other than they will not refund my money only an in store credit. The options they have given me.
1. Take menards instore credit. Then I will attempt to fix it.

2. Take a new redesigned tundra that they claim they have fixed the issues on. Below is what SBI told me they have done to fix it.
"The new production of this unit has taken into consideration the faults that were present in the current model. Refractory bricks have been added to the front of the firebox. The heat exchangers and firebox are now independent from each other eliminating the potential stress from expansion which caused the initial cracks that you experienced."

3. Wait till the end of this year for a new model they are planning to release called the Heatpro. They would credit me for tundra then i would have to pay the difference approx $1000 according to whom Ive been in contact with. No specs are available yet because its still in testing phase so dont know anything about it. Rumor is its a tundra version of the max caddy.

4. Take the menards credit. Load the furnace in the back of my pickup with tailgate down and drive down a bumpy gravel road. Then buy a propane furnace.


Though option 4 is how I feel most days I enjoy cutting splitting and burning wood. Grew up with it and hated it. Swore I would never burn wood when I finally owned my own house and constantly tried to talk my parents into propane. Long and behold first thing i did was put in a wood furnace. My dad enjoys giving me a hard time about it. Even tho he burns propane now..

I really just wanted my money back because I was set on buying a max caddy when all my problems started but now that is not an option I need some input. First has anyone received one of the new units? Are they actually fixed. Second has anyone heard any more details on the new model they claim they are developing. Third has anyone taken the credit and fixed their old units. This thought has crossed my mind as I used to weld for a living and could easily do it. My concern is if the front of the furnace has cracked what else has cracked and do I really want to leave it burning for 10 hours a day while im at work. (Correction that would be six hours since I cant ever get the burn times others seem to get.) I plan to tear it down and do good inspection inside the furnace just curious if anyone has done this already. Any input would be great. Sorry for the excessively long post.. I have lots of other questions but will start there for now. Thanks

 

[DoubleB]

Clayh88,
Welcome to hearth. Thanks for posting and contributing your experiences to this thread.

I was also only able to get in-store credit at Menards. Not entirely a refund by my definition, and I still have a long ways to go of "free" purchases at Menards now, but will recover my money eventually.

Of your 4 options above, I think you can do more than one. For me, I'm doing option 1 in the near term, to give me time to wisely decide whether to subsequently do option 2, 3, or other (Caddy, Max Caddy, Kuuma, or any other furnaces that might enter the market in the next year or two.) I'm adding temp control to the damper and firebrick to the front of the damper to prevent the cracks from spreading.

It's encouraging to hear SBI report they are adding firebrick to the front of the firebox. Not only is it a fix, but as we've figured on this thread it's actually the right fix, and also something you and I can do to our existing furnaces fairly easilt.

I plan on using my Tundra a year or two before deciding whether to purchase a new furnace to see if other owners can confirm the cracking has stopped (again, back to option 1). I think my existing furnace will serve fine as long as the cracking is under control, which is something that I can mitigate and monitor.

I haven't heard of a larger Tundra, other than @bpwelding2005 made a post about it. When I got my refund in March I specifically asked SBI which furnaces they have (present or future) other than Tundra that they would recommend to me, and their sales only mentioned the Caddy and Max Caddy.

I cleaned out my furnace pretty well a few weeks ago, and didn't see any more cracks. Although, I can only see so well, and certain cracks would be very easy to miss I suppose if they did exist.

A few times this winter I had trouble keeping my secondaries going, so I think all of my wood was probably on the moist side even all the other times the secondaries seemed fine. Now that my wood stacks have had an extra year to dry (for 15/16 winter) I expect the Tundra will perform much better and be more enjoyable to operate. I'd expect you would have the same success, unless you have other problems unrelated to wood (draft, chimney, etc.) If so, that's a different troubleshooting exercise. But I'd hang in there and keep burning wood, but that's just me.

Good luck!

 

[brenndatomu]

Good to hear that the current pool of thought about shielding the area subject to cracking is actually on the right track.
As I stated a couple posts back, I have acquired a Tundra (actually HeatMax) that has cracked and I just finished the install in the last couple weeks, just in time to fire it once during a particularly cold night. I made stainless steel shields that fit against the front of the firebox, bottom to top. I also put some ceramic insulation under the SS too. We'll see what that does.
I was going to weld the cracks first, but I decided to leave them alone to see if shielding this area made any real difference or not, you know, make one change at a time and all...anyways, I took pics of my mods and will post it here as soon as I can

 

[brenndatomu]

OK, I finally have a free moment to update y'all on my recent Tundra mods as mentioned in my previous post. I decided to install this "failed" Tundra that I recently acquired, as an "add-on" to my Yukon. Yukon is working on a "EPA" firebox to meet the new EPA regs and I figure the Tundra will buy me some time to figure out what is gonna replace my current Yook down the road. (The Yukon works great now since I have modded the firebox for a proper secondary burn, but it is also now a bit too finicky for my wife to run. I am on call all the time for work and I need something the wife can run without any problems, hence a future Yukon upgrade or replacement is likely to happen)
Anyways, this Tundra is a first year model (#352 I think it is (or was ) the PO pulled it out to replace it with a Max Caddy after the cracks happened. The cracks are only two, each about 1/2" long, at the top corners of the loading door. I was gonna drill/weld the cracks, then install the new heat shields, but then I thought, hey, it's already cracked, I'm gonna leave the cracks alone, see if shielding this area will actually stop the cracks where they are. If so, then it should also stop them from happening in the first place. I also did this same mod on my sisters new Tundra before it was fired the first time. I also have temp controllers to install on 'em both too, just hasn't happened yet.
I was gonna insulate using firebrick but couldn't figure out how to keep them in place. After doing what I did, I realize that the bricks could be installed the same way I did the SS, just hafta cut 1" or so off of the front of the bricks on the sides to tuck the new bricks in the "slot".

I went to a local fab shop where I buy metal sometimes looking for some "scrap" SS, or a cutoff/drop. I should have asked what it was gonna cost because after they sheared a piece off, the total at checkout surprised me a bit. $55 for a 3" x 6' piece of 1/4" 316 SS (enough to do two sets of shields) 304 would have been fine, but I guess the 316 is what they had laying around. 316 is actually a lil better for high temp applications, but either would've worked.

I removed the factory heat shield that is on back of the "air intake" box. To remove it is just two bolts, one straight up, in the middle above the loading door, and one one the back side, again in the middle. The shield will drop right out once unbolted. Here's a pic of it out.
Back side... Front...

Then I removed the front firebricks. Unbeknownst to me, there is 1/8" thick ceramic insulation blanket behind the bricks. Mine had creosote flakes piled up behind them, I guess from above the baffle. Anyways, I removed the rest of the firebricks so I could clean out behind the blanket, but it was stuck fast in some spots and quickly disintegrated when I tried to work it loose. I bought a replacement blanket(s) from a guy on fleabay (2 pieces 18" tall x 24" long needed)
Once the new blanket was in place, this is what I had... sorry bout the pic quality, turns out that taking good pics of the backside of the front of your firebox is a bit challenging! You are looking at the backside of what is at the right side of the door when you are facing the furnace.

I cut the SS to fit around the air intake box and a slot to fit over the firebrick retainer tab.
These pieces are 18" tall x 3" wide... Then I cut some 1/2" thick x 3" wide ceramic insulation that I just happened to have layin around, to match the size/shape of the SS. It goes between the firebox wall and the SS...
...like this...

I re-installed the firebrick, which BTW I had to trim up just a bit to get the extra clearance needed. The parts break down pics show the top rear brick (sides) being notched out to clear the tabs that hold the back of the secondary air tubes to the firebox wall, mine weren't notched, so I notched them 1/4" or so. Many off the bricks also had a bit of "flashing" on the sides left from where they were cast, this had to be cleaned off all the bricks to get things to fit also. Once that was done everything fit like a glove
Here it is assembled, left side of firebox... right side...

Here is final assembly, notice the factory air intake box shield is back in place and covers the edge of the SS (very top of the pic)
BTW, it is easier to take these pics using a mirror, like in this last pic

 

[DoubleB]

Brenndatomu,
Very nice! Thanks for the helpful post. I'll have to study it again once I get around to my Tundra.

How hard was it to remove the air intake box bolts? Has the heat made them risky/difficult, or were they easy?

 

[brenndatomu]

How hard was it to remove the air intake box bolts? Has the heat made them risky/difficult, or were they easy?

Not bad, they both broke free, turned a bit, then locked up. I ran them back in, sprayed the threads with WD40 (accessible under the intake damper flap) then worked 'em back and forth a bit, they came right out.
Some of the firebrick was a lil difficult to work loose, they were kinda tight because of ashes in the cracks and the creosote falling down behind the insulation blanket, but some patience and a gentle touch will bring 'em out in one piece.
Speaking of the insulation blanket, I thought of not putting them back in, so to get a bit more heat transfer to the firebox walls ( I have no clearance to combustible issues at all) but decided that doing so may affect the secondary burn time, so back in they went