Outdoor wood stoves

Any of y'all have an outside woodstove? Also known as a wood fired boiler even though they dont boil. I am considering buying or building one and would like some pros/cons.
Thanx.

I don't have one yet, but the ones that Central Boiler make seem to be very well thought out. When I get my own acreage, I will be buying one.

www.centralboiler.com

Alan

I have an aquaintance who has one. He burns anything in it and loads it with a loader. Big hunks of willow. Youll have all your buddies dumping wood at your place and telling them thast your gas bill was 20 bucks last month. Dryer and water heater.

I have a Heatmor outdoor boiler that I have been using for 5 yrs. now. When I laid down my cash, which is a sizeable amount for any of these, I had narrowed my choices to Heatmor and Central Boiler aka, Classic. I`ll tell you the reasons why I chose Heatmor over Classic and then the hard part, spending the money, is up to you. Heatmors are all stainless and built in unitized assemblys using components available at just about any HVAC supply house . For example the blower for induction is a Dayton part # available from Grainger`s, shipped to your house. The expansion bladder is an implement inner tube. The aquastats are off the shelf items. Just about any boiler anode will work. And you don`t need to add chemicals to the ash or the water to keep your warranty in effect. If you do ever have a loss of integrity(it leaks), the Heatmor is field serviceable by the dealer without voiding the warranty, and the major components can be removed in the field without use of a crane or special tools if they need major repairs or replacement. The Classic gets loaded on a flatbed at your expense, and there is an $800 transportation fee back to the plant where they determine if it is a legit warranty claim. The Classic has an electric damper mechanism that has to be ordered through an authorized dealer when it fails, no sweat as long as the dealer stayed in business right. Creosote buildup is also a problem for wood fired boilers if they don`t have forced induction. With the relatively cool interface between the water jacket and fire box, you can get huge accumulations of creosote which hampers heat transfer to the water. I `ve seen this on a couple of Classics I looked at before buying the Heatmor. You must also add a chemical to the ashes to neutralize them so they don`t corrode the ash pan, there are no grates which also prevents burning coal. You must also use Central Boiler`s water additive to maintain your warranty. The Classic is open to atmosphere so you have continual water loss, Heatmor uses a simple ball in the vent that is weighted so that it lifts at between 2 and 3 lbs. so it virtually eliminates water loss and it is still non-pressurized. The Heatmor has an auger system for cleanout meaning you can clean it with a good fire going. This makes scheduling cleanout alot easier. The Classic has to burn down, and then you push the embers to the side and scoop out the ash. The Heatmor warranty is double what the Classic warranty is also. I do believe that the Classics are a little more efficient due to the foam insulation they use versus fiberglass on the Heatmor. Heatmor claims to use fiberglass for field servicability, but when I called the parent company, I was told that I could use whatever type insulation I wanted with no effect on the warranty. Heatmor also has an over/under draft combustion which works very well compared to the over draft system of Classic and many others on the market. If any one has any questions please contact me. I do not sell any of these although I did at one time. When it`s all said and done, it was money well spent, but next time I will build my own. Oh yeah, skip all the fancy pipe insulation they try to sell you at exhorbitant prices. I`ve seen alot of different installations, and the best ones used PEX pipe inside coiled non- perforated drain pipe, on saddles to keep it from the edges. Seal the ends with canned foam and bury it below the frost line. Russ

Water Loss

I forgot to tell you why continual water loss is more than just a PITA. Adding fresh water all the time adds more corrosion products. It also means evaporative loss of those fancy chemicals you have to put in, and of course, lost Btus out the vent. Russ

Thanks Russ, I have more questions to ask later.
Steve

Ok Russ, (and anyone else who has one of these) here goes.
My bro in law has had a heatmor for a few weeks and it seems like a nice unit although as you have eluded to, very$$$ around $6000 installed. I have looked at virtually every one of these on the market (around 15 or so) and the only MAJOR difference I see is whether you buy a round one or a square one. Effiency is somewhat dubious because of the fuel involved. I have a fairly large farmhouse ( 4500 sq.ft. incl, basement) and all the dealers I have talked to want me to buy a very large unit meaning big time $$$,. My questions are: How many sq. ft. are you heating? What model is your stove? Do you heat your house water with it? What dont you like about it? How far away from your house is it? Do you have forced air? Did you insulate your pipes at all? Any problems with air in the lines? If I get one of these I will build it myself as I have access to all the equipment to do it and save some serious cash. Check out www.deb-design.com. I bought some plans from this guy and they seem pretty good. Thank you for your previous response and thanks in advance for any info you can give.
Steve

If that link didnt work, try http://deb-design.com
Steve

Russ, does Heatmor have a website?

Alan

www.heatmor.com
Steve

Hi Steve, I have the 200 model from Heatmor and I`m heating about 4800 sqft. Three above ground levels and a finished walk out basement. Mine is about 155' from my house and interfaces directly with a propane fired boiler in the basement of my home. By directly I mean that there is no auxiliary heat exchanger, I`ve tapped an input and return line into the return header of the gas boiler and placed an isolation valve between them for winter when I don`t want to burn gas. I heat my domestic hot water with a 42 gal. Amtrol tank as another zone off the boiler and it works very well. I don`t think you could run it out of hot water. I also use the gas boiler for domestic hot in the summer, this keeps the cast iron heat exchanger in the boiler dry and I don`t have to fool with the Heatmor. I use a seperate Taco 012 high velocity circulating pump, in the supply line from the 200, run off a relay powered by the boiler control, and I installed a switch to de-energize the single boiler circulator on the gas boiler and let it freewheel during the heating season. The 012 is more pump than I need, I had to install throttled bypass valves in two zones to eliminate waterhammer. The worst thing about my boiler is the backdraft you get sometimes when you open the door, especially if a burn cycle recently ended. The new Heatmors have an interlocked damper to the firebox that opens when you open the outer door, conceivably eliminating that oxygen starved condition. It`s a very simple affair with a rod and a flap, looks like it would work on any of them. These boilers do not burn nearly as long as the manufacturers would like you to think. When it gets down to -20 or -30, a FULL charge of wood only lasts about 13 hours. When I say full, I mean almost couldn`t get a toothpick in there. It`s all seasoned hardwood, alot of cherry which isn`t the best in terms of heat quality but it`s good. Burning unseasoned wood will give you a noticeable decrease in burn time per loading. It is very windy where I am, right off Lake Ontario on the southeast end. I did insulate my pipes which are buried at 4'. I used closed cell pipe insulation because that`s what the dealer I bought from had used for years when he sold Taylors. In all but the coldest times of the year, I have green patches over the pipe into my house. mmmm? I run my Heatmor at 165 degrees indicated and it shows 140 degrees on the thermometer on the gas boiler. These aren`t lab quality thermometers but I`ll bet that they are close enough. I have plenty of baseboard in the house so this temp is adequate and it gives me a longer burn time. I do like the Heatmor because you are only trying to keep 150 gallons at temp versus twice that in a comparable Classic. I would rather have the energy in the wood than in the water. Heat transfer, ie:heat loss is dependent on temperature differential betweeen the heated water in this case and the outside air, and the temperature of the water is a measure of the BTU content, so more gallons means more BTUs to lose. I have never had a problem with air in the lines, I have what is known as an air scoop with an auto vent installed and it works very well. They are only about $50 if my memory serves me. As far as building one yourself, I`d say go for it as long as you go non-pressurized. I built one once but that is a story for another time and another place, had somthing to do with increased efficiency of a pressurized unit, the expansive properties of superheated steam(up to 60 times volume) and 2500#s of hot flying steel. LOL, now anyways! Feel free to email me at [email protected]. Sorry to clog up this thread with such long posts. Russ

I am curious about the chemicals added on both the wet side and fire side in the Classic boilers. Are there different chemicals available depending on the chemical qualities of the makeup water? Are the fireside chemicals added to the fuel, or to the ash?

Aqua-Therm Outside Wood Boiler

Aqua-Therm has a Very good unit!

Classic (Central) I've seen many rust out in 3 years (Yes Three Years) The Warranty is that there is NO Warranty!

The Heat Mor is OK

------------------------------ Direct From Aqua-Therm.com------------------------------
15 YEAR WARRANTY

All Aqua-Therms with the stainless steel firebox have a 15 year limited warranty. In the first 5 years, the warranty pays 100%. In years 6 through 15 the coverage is prorated. All components and controls have a one year warranty.

Ask for references. Aqua-Therm has an excellent reputation for standing behind its products.

Fire box corrosion is covered.
------------------------------------------------------------------------------------

Aqua-Therm Website
http://www.aqua-therm.com

Hi Steve, I`m wondering what makes you say that Aqua Therm has a very good unit but the Heatmor is O.K. ? I hope it`s not just based on the advertised warranty. At any rate, this is a sincere request for info. I know I have done alot of preaching about Heatmor vs Classic, but my knowledge may be somewhat dated. When I looked at the Aqua Therm, I also thought it looked like a good unit but the grates where very cheesy looking. Didn`t look like they would hold up. Do you have an Aqua Therm and how long have you been operating it? One thing I learned when looking at outdoor boilers is that there is alot of chest beating amongst dealers, and manufacturers, and many of them have virtually no first hand experience with boilers of any sort, never mind wood fired boilers. The only criteria to become a dealer for any of the brands I looked at was the ability to be able to "floor plan" a certain number of units, often just enough to pay for your own after selling the others at retail. I did sell Heatmors for a while, but after having used one for almost two years. I think the Heatmor is a very good unit, I don`t know if it`s best now or ever was. I just couldn`t stand all the crap of trying to sell them, primarily talking to people who wanted you to do a real lengthy estimate with a highly detailed drawing of the installation and all necessary components thrown in, and then the other end of the spectrum, people who couldn`t fathom how you could have the heating unit outside the structure, but are more than willing to have you spend copiuos amounts of time trying to educate them. Or the other folks who expect to be able to buy at wholesale prices and get free delivery to boot. The margin for the dealers on the Heatmor and Classic is not all that high. Initially it sounds like good money until you sit down and crunch numbers on how many units you can realistically sell, and what kind of specialized equipment you need to receive, deliver and install these things, then factor in that the dealer is expected to stock an inventory of units, accessories, and replacement parts, which can add up to substantial money tied up. And then you have to be a good liar to sell alot of these things anyway. Tell people what they want to hear and don`t worry about them motherf**kering you after the sale when they realize they are more work than you promised, and the payback period is alot longer than you promised. Or how about the people out in East Bumf**k that demand that you come out and fix the shoddy installation that they paid someone else to do, at your expense, because the original dealer/installer is defunct and the company rep gives them your name as a dealer. These people, even though they actually conducted no business with you, are not averse to bad mouthing YOU when they have a problem. In a very simplistic way you can`t blame them, they got sold a bill of goods and you are associated with the company name. You also have to factor in the amount of time required to go to shows, all over the region at your own expense typically, to show them. They need to be advertised agressively to sell. Don`t get me wrong, I enjoy sharing my opinions and what I think I know. I guess I just felt patronized when people implied that they were able to buy and wanted to buy, but you knew they were just putting on a front so that I would spend my time, often driving to their homes or business', just so they wouldn`t have to put forth any effort. I know I`m off on a tangent here, I just wanted to give the reasons why most dealers don`t stay with it for long, and once your dealer is gone, what are you going to do? Especially if your unit requires OEM parts, or is not field servicable. I think that the manufacturers are making a killing by the sweat of the dealers, and the manufacturers from what I have seen provide minimal support. I say find a way to build your own. From what I have been told by asemi driver delivering a load of these to me, they are all over the country side of Minnesota, all home built. I know what it cost to build one, and it`s not alot, and i know that shipping, markup, and adverstising is significant. After all the bitching I`ve done about people picking my brain for free info I doubt anyone will ask again, and I`m sorry because I don`t mean to discourage anyone here. I `ll be glad to respond to anyone with a question, on my own terms/timing. Several of the posters here can attest to that.
To Christain: the chemicals for the water are generic anti corrosion mixtures that I have seen, although they are sometimes given proprietary packaging. Most boiler supply or well stocked hardware stores have them. The fireside chemicals go into the ash to neutralize the accidity. Sorry about the long winded reply. Russ

Heatmor has a good unit but the reasons that I like the Aqua-Therm better is:

1 - Easier Ash Removal (No Long awkward crank)
2 - Easier to load wood into (Not as big of drop off from door opening)
3 - Less Creasilte Sp? (heatmor's I've seen the inside is all covered) Not very much in the aquatherm
4 - The warranty is good (read below)

I have run an Aqua-Therm for 9 years the first 4 I had a carbon steel model that rusted out! ( I did not take the best care of it did not clean it out that often ) But Aqua-Therm gave me a new Stainless Steel furnace (I had to pay a couple hundred dollars for the price difference from carbon to stainless) I have been running that one ever since with no problems.

I've not had a problem with the grates, i've thrown some big wood in there. Every summer I will pull the grates and clean everything out. The grates have never bent.

The HeatMor I'm comparing to is my brothers unit that I run when he is out of town.

That`s interesting Steve, thanks for the reply. If you have been running that long on the same grates, they must be pretty good. Sounds like they really stand behind their warranty also. I`ll have to look closer next time I see one. Russ

Hey All,
Since starting this thread, I have decided to build my own unit.( thanks for your e-mail, Russ.) I am going to build a round one, similar to Aqua- therm ( I have heard good things about them) but if I am not mistaken, all aqua- therm units are pressurized units. 15-18psi. Mine will not be. Does anyone have any experience with non- pressurized units? Specifically Pacific- Western or Woodmaster or Northland etc... I am amazed that your Aqua-Therm rusted out in 4 years! Did you leave the ashes in it during the summer Steve? I'm asking because I am planning to build mine out of Hot rolled steel and want to know just how conciencious I'm gonna have to be. Thanks for all of your input,
Steve

One thing that I have noticed with all of these units, is that they do not use firebrick. Does anyone know why? Would this help/hinder the corrosion of the firebox? Is there some other problem that using brick creates?

Alan

Fire Brick

Heatmor uses fire brick. There is a course right above the sand bed in the bottom, right where all the hottest coals would build up and rest against the sides. Wood fired boilers probably don`t need fire brick because the metal shell of the fire box, which is the inner wall of the water jacket, doesn`t get hot enough to oxidize from the flames. Especially if it`s stainless. I don`t advocate carbon steel for any boiler because of corrosion, but to each their own. Well water is notorious for being hard, meaning it has alot of corrosive minerals and elements in it. Softened water is just as bad with the salt present. Russ

I am considering the option of building an outdoor stove myself, but there is also the option of geothermal...has anyone had experiences with geothermal heating...I realize the cost is alot more initially..(15,000cdn)(200usd)...but from what I understand it will pay for itself in the end...I have a reasonably small house but a large store and shop, and I was thinking I could heat both..is that possible with the outdoor wood heat?...