# Thermo Control boiler gasification?



## Chris VanMaaren (Jan 2, 2013)

I am new to boilers but am looking to put an add on to my oil powered water baseboard heating system and found the Thermo Control boilers.  They describe themselves as gasification units but I'm not sure if you guys would agree.  Please check out their Model 2000 and tell me what you think.
http://www.thermocontrolheating.com/

I like the idea on an add on set up as I wouldn't have to redo the unit and would still have a way to heat the house when I wasn't around to add wood.

Thanks


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## rwh442 (Jan 2, 2013)

They are natural draft conventional boilers.  I have a 2000 model and it has done well for me.  Load it about 3.5 times per day depending on wether.   My average wood consumption has been about 7.5 - 8 cords per year.  2000 sq ft ranch house, full basement, kept at 71 all year.  Boiler is in a 1600 sq ft detached 3 car garage that averages low to mid 60's due to the radiant heat off the boiler.  That being said the boiler would use much less wood if it was installed in my basement.  I'm happy with the setup though because I play in the garage often.

I'm sure a gasser is more efficient but cannot put numbers to it.  I have no storage other than the 130 gallons the 2000 holds plus lines, expansion tanks and have no issues.

I initially had issues with overfire or high stack temps but added draft controls four years ago that limit my stack temps to 600 degrees and it has behaved itself since.  Just load and walk away - simple.


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## Chris VanMaaren (Jan 3, 2013)

Thanks for the info rwh442.  Does it burn fairly clean or will it build up creosite in the chimney?  I have an old chimney from an oil unit that was in the garage and I could work with that but worry about having 2 turns in the pipe.


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## Trex83 (Jan 3, 2013)

Hi Chris,
do you have more info on the clearances of your older chimney?
Is it a Class A or Class B. You may want to install a Class A. Some other members would advise you better than me. The older chimney might be to rusted out or not have proper clearances because the flue of an oil burner is less than a natural draft single stage solid biomass burner. I would go all new with a clean-out adapter and a draft regulator. You will use less wood with a new draft regulator.
Think about the insurance guy; the next time he walks in your garage... Don't forget to clean oil stains on the cement too!
Good luck, if you are on this website, you are on the right track!
Trex83

ps picture is good too


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## Standingdead (Jan 3, 2013)

I have the model 2500. It's a natural downdraft as well. I go through 8 cords or so a year. It's a good efficient boiler but not a gasser. The 2500 has 175 gallons on board storage. Runs pretty clean with dry wood.  Overall I am pleased. It works the way it's supposed to. Does like to eat a lot of wood though .


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## mustash29 (Jan 3, 2013)

I looked into the Thermo stove / boiler units.  They have basically the same firebox design, just depends on if it has water pipes in it or an actual water jacket.

The primary air enters through the front door, around the fuel, and has to go "down" to get around the sloping rear smoke baffle.  This sort of makes the gasses flow past the coal bed, not through the bed like an actual downdraft gassifier.  The secondary air enters through 2 pipes on either side of the load door and is injected in the rear, near the smoke baffle.

IMO they _*act*_ like a gassifier to some degree.  If you want to get technical, any EPA stove with secondary burn tubes in the roof is also a gassifier, just in updraft form.  IMO a full downdraft design is best since the smoke must go through the coal bed, which is the hottest part of the fire.


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## rwh442 (Jan 3, 2013)

Chris,

Creosote buildup depends on how you burn and wood moisture.  If I load the 2000 up at low water temps the chimney will get a dull sound when hit or smacked by hand (highly scientific).  If I burn small hot fires at higher boiler water temps (say above 140 degrees, 3 logs) I usually have a clean stack after that type of burn and of course no smoke at all.  Tinny sound when checking the stack.  I used to clean the chimney a few times each year but once I learned how to run it best and have good seasoned wood I only clean the chimney after the burning season in April.  I might get about a half gallon to a gallon of ash and creosote and almost all of that is in the 8" outlet pipe IN the boiler.  The chimney buildup is minimal.  My chimney is pure vertical straight up - no bends.


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## Chris VanMaaren (Jan 4, 2013)

Thanks for the help.  I guess the bottom line question for those that have a Thermo Control 2000 or bigger is: would you buy it again or look for something better (less wood etc).


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## Standingdead (Jan 4, 2013)

Chris VanMaaren said:


> Thanks for the help.  I guess the bottom line question for those that have a Thermo Control 2000 or bigger is: would you buy it again or look for something better (less wood etc).



I would buy one again. It's simple to install and maintain. It works well. It's efficient (1 cord of wood burns down to a 5 gallon ash bucket or so). It's a bit cheaper than a top of the line gasser 4-5k. Yes you burn a little more wood but if you process your own wood that's not a big deal. It's also capable of burning rounds if your so inclined. I never had a gasser so I have no way to compare.....


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## rwh442 (Jan 4, 2013)

I would buy one again also.  I know a gasser would use less wood but you have to split it smaller too.  I would bet the time would come out about the same.  If I come across a knotty piece I can't split it becomes an "all nighter" and gets stacked along with the splitters.

A much simpler design obviously.  The fire brick is the only refractory and they are standard stove size - you can get them anywhere.

A local farmer here has a 1978 Thermo Control stove model (not a boiler) and is looking to first replace it now because it's obviously worn out.  My father has the same year stove model, which he quit using about 15 years ago, that the guy  wants to buy from him but my father refuses to sell his.  So if mine holds up that long (I doubt it but wishful thinking) that would great.


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## 711mhw (Jan 4, 2013)

I know a guy that sells them, he's a "stand up" guy that says good things about the boiler (expected) but also that the folks that make them are good people, and stand behind their product 100%.


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## Dan Giesen (Jan 9, 2013)

rwh442 said:


> They are natural draft conventional boilers. I have a 2000 model and it has done well for me. Load it about 3.5 times per day depending on wether. My average wood consumption has been about 7.5 - 8 cords per year. 2000 sq ft ranch house, full basement, kept at 71 all year. Boiler is in a 1600 sq ft detached 3 car garage that averages low to mid 60's due to the radiant heat off the boiler. That being said the boiler would use much less wood if it was installed in my basement. I'm happy with the setup though because I play in the garage often.
> 
> I'm sure a gasser is more efficient but cannot put numbers to it. I have no storage other than the 130 gallons the 2000 holds plus lines, expansion tanks and have no issues.
> 
> I initially had issues with overfire or high stack temps but added draft controls four years ago that limit my stack temps to 600 degrees and it has behaved itself since. Just load and walk away - simple.


 
What do you mean by draft controls? The only draft control i'm familiar with is the spinning plate within the pipe


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## rwh442 (Jan 9, 2013)

I inserted a type K thermocouple probe about 2' from the exit of the boiler in the stack and wired it to a PID digital temperature controller. The temperature controller sends a control signal to a damper actuator I mounted to the front of the TC 2000 door. I control the stack temperature to whatever I want - I found 600 degrees is good. The controller has a relay output as well that I set to kill the power to the factory spring loaded damper - I think I have it set to 750 degrees - in case the damper actuator cannot catch the fire in time (it is very slow). See attached pictures.

I had a chimney fire Christmas Eve about 1 month into running this boiler the first year (about 4 years ago).  I was at a nearby family's house.  No damage but I swore it would never happen again so I added this protection.  Obviously I know how to run the boiler much better now and may not even need the controls but I like the piece of mind.


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## Standingdead (Jan 10, 2013)

rwh442 said:


> I inserted a type K thermocouple probe about 2' from the exit of the boiler in the stack and wired it to a PID digital temperature controller. The temperature controller sends a control signal to a damper actuator I mounted to the front of the TC 2000 door. I control the stack temperature to whatever I want - I found 600 degrees is good. The controller has a relay output as well that I set to kill the power to the factory spring loaded damper - I think I have it set to 750 degrees - in case the damper actuator cannot catch the fire in time (it is very slow). See attached pictures.
> 
> I had a chimney fire Christmas Eve about 1 month into running this boiler the first year (about 4 years ago).  I was at a nearby family's house.  No damage but I swore it would never happen again so I added this protection.  Obviously I know how to run the boiler much better now and may not even need the controls but I like the piece of mind.



I am curious what you think caused the fire/over firing. When I bought my stove it came with a stack probe and motorized control to close down the air once the stack reaches 350 or so. At that point the boiler is just drawing air in through the secondaries. I feed the boiler 6 times a day with the only "large" load going in at night (depending on boiler temp and expected overnight low this could be anywhere from 1/4 to 3/4 full. It runs cleanly for me with a little smoke when I reload.


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## rwh442 (Jan 10, 2013)

My year one wood was less than ideal.  I would always load it totally full.  So I must have had some poor burns and creosote buildup.  Once that happens the stack limit switch is slow to respond due to any buildup (my guess).  I must have had a clean hot burn and then a chimney fire.

I added the draft controls with the temperature sensor (type k thermocouple probe) internal to the stack.  So now it cannot run away.

I studied the stack limit switch with clean chimney and burns and found that it goes off around 650 degrees internal stack temp with my setup and the gap recommended.  It's still in the spring loaded damper circuit so it can shut the draft off as well.

My burns are much cleaner now.  So like any stove or boiler there is a learning curve.


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## Dan Giesen (Jan 14, 2013)

Standingdead said:


> I would buy one again. It's simple to install and maintain. It works well. It's efficient (1 cord of wood burns down to a 5 gallon ash bucket or so). It's a bit cheaper than a top of the line gasser 4-5k. Yes you burn a little more wood but if you process your own wood that's not a big deal. It's also capable of burning rounds if your so inclined. I never had a gasser so I have no way to compare.....


 
I am thinking of buying the model 2000 and putting it in my basement. Would you go with the clad or un-clad model? I'm thinking the insulated model would be better.


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## Standingdead (Jan 14, 2013)

I have the unclad model 2500. Its rated to produce 40k BTU's of ambient heat, putting another 160k of BTU's in the water. When running the boiler at say 140 degrees or more heats my basement to 75-80 or more degrees. To combat this problem I put in a powered vent that pushes the excess heat upstairs. It works very well for me. At seasons start I store 5 cords of mid season wood in the basement. Sitting months in a hot dry basement helps lower the moisture levels. It's also I nice place to "hang out" after working outside most of the day.


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## rwh442 (Jan 14, 2013)

As Standingdead said, you will have a warm basement if non-insulated.  Mine keeps me detached garage plenty warm and it's around 1600 sq ft.  I would probably have it insulated.


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## Dan Giesen (Jan 15, 2013)

Standingdead said:


> I have the unclad model 2500. Its rated to produce 40k BTU's of ambient heat, putting another 160k of BTU's in the water. When running the boiler at say 140 degrees or more heats my basement to 75-80 or more degrees. To combat this problem I put in a powered vent that pushes the excess heat upstairs. It works very well for me. At seasons start I store 5 cords of mid season wood in the basement. Sitting months in a hot dry basement helps lower the moisture levels. It's also I nice place to "hang out" after working outside most of the day.


 
The model 2000 has about 130 gallons of water in it. In your opinion how well do you think that much water heated to 180 would keep the house warm when the fire dies down? I know there are a lot of variables but i'm just asking what is your real world experience. It would be nice to load up the fire box before work and come home 12 hours later and still have the house warm.


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## rwh442 (Jan 15, 2013)

I leave for work right around 6 am.  Get home around 5 pm.  I loaded it at 120 f this am and the water temp was around 85 when I loaded it again tonight.  House was still at 71 degrees but the furnace fan was running.  My 2000 is in a detached garage.  That being said I am almost positive that if you insulate a 2000 and place it in your basement you would be fine.  In any case you can catch up easy if needed.


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## Standingdead (Jan 16, 2013)

With so many variables it's hard to say if you will get a 12 hour burn. I generally max out at around an 8-9 hour burn and using up the on board storage. My unit stores about 100k BTU's of heat. You go through that pretty quickly on a cold night. the unit your considering stores less, about 70k BTU's of heat. Keep in mind I almost never completely fill the box as I would rather have several smaller/hotter/cleaner fires. Even without the jacket I like this unit as the radiant heat is still in the house. With the basement so warm my first floor hardwood floors are usually 75 degrees. This includes the kitchen which makes my wife VERY happy!


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## maple1 (Jan 16, 2013)

If you get the uninsulated one, you will likely be finding it too hot in the house when burning when it's not very cold out. I started out this fall deciding to not insulate my newly installed storage tanks until spring. I soon changed my mind on that - it was getting just too darned hot in the basement & first floor. However, I then found it too cool in the basement on cold days. I fix that now by cracking one end of my insulated storage box open a bit when it gets real cold out. So, I'm not familiar at all with the Thermo units, but I'd be tempted to get an uninsulated one, and do some insulating of my own (as long as it could be safely done) that would allow you to easily regulate the amount of heat it radiates or not by maybe pulling an insulation panel off or opening it up or something like that. It is nice on real cold days to have a huge radiator to take advantage of if wanted.


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## rwh442 (Jul 24, 2013)

Bump for recent Thermo Control inquiry.


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## Bruce2500 (Nov 16, 2013)

Hello, I am new to these forums but reading through the strings it seems there are ideas here that will help with my dilemma. I have used a Thermo-Control 2500 for 5 seasons skeptically going into the 6th. My stove appears to be what they offer as the 2000 today. My problems is that the high stack temp limit switch is what shuts the front damper down 90-95% of the time, resulting in the high temp limit ultimately controlling my boiler water temperature, not a good scenerio. I see the aguastat controlling the damper maybe 4-5 times a heating season. So I get a problem with the boiler keeping up with my heat demand because it's out on high limit which is a timed reset and vicious cycle. Damper reopens, air races through heats pipe and trips on high heat again. While the damper is forced closed the smouldering fire is now sooting up the chimney. Not uncommon for me to go on the roof and clean the chimney every Saturday morning. I am interested in what rwh442 did with the damper control. You must have set that up to modulate and seek a position that will keep the temp around 600 degrees. How is your linkage set up to accomplish this and also shut it completely down should you get a high temp situation? Any ideas would be greatly appreciated as I just can't see what I'm doing wrong.


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## Standingdead (Nov 16, 2013)

What kind of stack limiter are you using? Mine originally came from manufactorer with a close limit of 250-270 or thereabouts. I went online an ordered one that triggers at 400-425. It was an easy modification. You can also try to insert washers between the switch plate and stack. By moving he switch slightly away from the pipe you can trick the switch into measuring 250 when in reality it's much higher. For what it's worth unit runs pretty clean at 400 and up. My aquastat is adjustable so I can shut the temp at 140 in shoulder season or 180 in winter. If your aquastat is not adjustable you might want to install a new one that is. I also burn smaller hotter fires until the late night load since i work from home. Good luck


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## Bruce2500 (Nov 16, 2013)

I have the original limiter with the added washers underneath. I have a laser heat gun and the cutout temp on the stovepipe surface under the disk is around 420. If the temp would stay there I'd be fine but that's my problem, the disk opens up at 420 and resets at about 170(it takes that long). If I set more space and had the disk opening at 500 or whatever, once the damper opened the stove would climb there and shut down and cycle, regardless of the boiler water temp. I jumped the switch out once and monitored the temp, it climbed to 700 no problem, probably would've gone more had I not stopped it???? My aguastat also is adjustable, I keep it at 180. I set the oil burner to 145 when running the wood boiler. Thanks for the response.


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## Standingdead (Nov 17, 2013)

Ah, I see it's the the length of time the switch shuts off the air flow is too long. I am curious what size splits you burning. As I mentioned I tend to burn small loads and fill often. My split sizes are relatively big say 24" long by 5 inch diameter. I found those bigger splits burn a little slower(cooler) and don't trip the switch. 3-4 make a nice 350-400 stack temp fire at its peak. Maybe they make stack switches with upper and lower limits? 250-450 would work nice for these stoves IMO.


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## Bruce2500 (Nov 17, 2013)

My wood is  split 24 long X  8(average). 5 would be small in my pile. I do tend to load up the stove to try to minimize load times, mostly out of necessity. Maybe a switch that shuts down at 600, but I don't understand why the company put such a low one with the stove in the first place. Calling back to the company numerous times gets me nowhere, they don't want to hear anything negative and any problems are created entirely by operator error. BTW, along with spacers under the disk I have also moved the disk away from the stove closer to the chimney inlet.


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## Standingdead (Nov 17, 2013)

I agree about the original switch being too low. Never called the company though. I figured i needed a different switch because my 35 foot chimney created a stronger draft than most. My liner stays pretty clean, I clean it twice a season. Sorry I can't remember the website I got the switch from. Let us know if and where you find a better switch. Thanks.


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## rwh442 (Nov 17, 2013)

Bruce,

The damper actuator I added to control my stack temps to 600 deg F controls the air flow into the bottom of the door intake box.  It regulates the air flow by rotating a plate across that bottom opening.  I capped off the top opening of the door intake box completely.  The OEM damper motor is still in use - I have it shut closed when either the water temps get to 185, the stack limit switch activates (mine seems to go off at around 650 or so while at that temp or above for a while), or when my PID stack temp controller sees a temp above 700 at which I am "out of control" and then open it back up around 550 .  I never really see my stack limit switch activate - my stack temps don't get there and stay there for long enough for it to trip.  I just left it in the circuit as another safety device.  Is your air gap between the switch and stack set correctly?


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## Bruce2500 (Nov 23, 2013)

rwh222,
You must have the linkage going through the door via a hole you drilled that turns your plate to open/shut air coming from the original damper opening outside the door? If I'm following you then this plate is roughly 13" x 1-1/2". My stove came with the top door intake sealed and only takes air from the bottom. I would be curious to see the inside setup if possible. As far as the air gap being set correctly, probably not. I have added about 1/4" of spacers underneath and moved it close to my chimney inlet to get it so it kills the system about 450. Even there it is still the controlling factor of my burn. I need to do something similar to you.


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## rwh442 (Nov 23, 2013)

Bruce,

The damper actuator I added is bolted to the bottom of the door intake box and hangs out in front of it and the door.  I just made a bracket for it out of sheet metal.  You should be able to see that in the pictures I posted in reply #13 in this thread.  If you need to ask further questions maybe send me a private message or "conversation" I think it is called in this forum and we can get in touch that way or even over the phone.


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## Boiler Installer (Mar 20, 2014)

Hi Bruce,

I am familiar with that stack limit switch and all you have to do is first of all put a thermostat on your black pipe about 18 inchs above the outlet of the stove.  Get the stove burning and watch the temp on the stack. The temp should rise to about 400 or so maybe 450. If it not reaching those temps, all you have to do is adjust it away from the pipe with a washer under each screw. Each washer will raise the stack temp. about 75 or 100 deg. The more washers, the hotter the burn.  This will fix your problem and it is the exact way you are advised to adjust the stack limit switch in the owners manual. You are not tricking anything. If the stack limit switch was mounted farther away from the top of the stove you would also get a hotter burn. Who installed the stove? 

Happy burning


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## mikjmartino (Dec 6, 2014)

Bruce2500 said:


> Hello, I am new to these forums but reading through the strings it seems there are ideas here that will help with my dilemma. I have used a Thermo-Control 2500 for 5 seasons skeptically going into the 6th. My stove appears to be what they offer as the 2000 today. My problems is that the high stack temp limit switch is what shuts the front damper down 90-95% of the time, resulting in the high temp limit ultimately controlling my boiler water temperature, not a good scenerio. I see the aguastat controlling the damper maybe 4-5 times a heating season. So I get a problem with the boiler keeping up with my heat demand because it's out on high limit which is a timed reset and vicious cycle. Damper reopens, air races through heats pipe and trips on high heat again. While the damper is forced closed the smouldering fire is now sooting up the chimney. Not uncommon for me to go on the roof and clean the chimney every Saturday morning. I am interested in what rwh442 did with the damper control. You must have set that up to modulate and seek a position that will keep the temp around 600 degrees. How is your linkage set up to accomplish this and also shut it completely down should you get a high temp situation? Any ideas would be greatly appreciated as I just can't see what I'm doing wrong.



Hi Bruce.  Put a washer between the pipe and the stack limit switch to space it out.  That was the suggestion from the tech at Thermo Control.  It worked for me and allows high temps.  I think someone else had that idea too.  It is easier and cheaper than replacing the switch.


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