Shelter wood furnace upgrade/Improvement

[Lawson111]

I have had my shelter furnace for 3 years now. Never really had any serious issues with it besides trying to keep the door handle adjusted properly but that’s not a huge issue.

What I would like to try though is instead of the air induction fan running off a thermostat in the house is there a way to hook that up to the blower thermostat? Or something similar maybe using a separate thermostat that monitors plenum heat. Really trying to get longer burns with this stove so I was trying the think of a way to set it up similar to a wood boiler where the induction fan will kick on when it calls for heat. But In this case when the fire box gets to a certain temp have it kick on to heat the fire up and turn the blower on.

I know this is supposed to work off a house thermostat the same way but I have had no luck with it. I have to choke the fire down so much in order to get this to work resulting in bad creosote and even puff backs.

Right now I don’t even use that induction fan I just monitor flue temps with a magnet thermometer on the stove pipe and adjust air intake with the bottom ash pan knob and plate on the side of the induction fan. Running it this way I burn a lot of wood and my house is 80 because the blower fan is constantly running because I try and keep the fire hot enough to not make a ton of creosote. It sucks having to clean the chimney every two weeks!

Any input or ideas would be great
Maybe someone with a shelter furnace can help me get this thing setup to burn and run the way it was designed!

Thank you!! Sorry for the long read.

 

[Medic21]

What model? What wood?

I just finished installing mine SF1000, and have had it running for 4 days. We are in the longest single digit temps ever and I am very pleased with this after the highest temp since wed has been 9. I have used zero propane since lighting it. I can't get more than 4 hours between loading with the thermostat set at 72. At 68 it will go 5 hours. The design in mine is to have the fire cool off between heatings and let the induction blower warm it up when it calls for heat. I do not have any other air inlet other than the induction blower. It stays clean since by the time the fire cools it is past the creosote stage. If your puffing it sounds like a draft issue.

 

[Lawson111]

SF2631

Wood varies, all hard wood, cherry, beach, birtch, hard and soft maple.

When you say it’s past the creosote stage do you mean your induction fan won’t kick on until it’s coal or near coals? If so does the induction fan really warm them up that much to bring the house temp up?

I always assumed it should be set up where it kicks on and off through out the entire burn not just the end of it. I just can’t see it working like this without making a bunch of creosote or having th puff back issues I’m having because you would really have to shut the air intakes down a lot to get that low of a burn. Unless your wood is very seasoned which mine is cut in the spring stacked under a lean to until October then brought in my basement.

The puffing I think I got figured out after it happened really bad today. I loaded the furnace with 6-7 pieces of wood and shut the door to soon before it was burning good. When I did this it starved it for air and resulted in a puff back. I never have an issue until I put a lot of wood on all at once.

I am changing my inside stove pipe setup to try and help the draft but I need to wait until we get out of the single digits. So I can shut the stove down.

 

[laynes69]

Both furnaces here are completely different, the 1000 is EPA certified, where the other is not. Coals after 4 or 5 hours sounds normal. From there, the induction blower should cycle to keep the house warm for some time after to stretch out the burntimes.

 

[Medic21]

Both furnaces here are completely different, the 1000 is EPA certified, where the other is not. Coals after 4 or 5 hours sounds normal. From there, the induction blower should cycle to keep the house warm for some time after to stretch out the burntimes.

True, I can open my firebox when the stack is around 250-300 and it is a very hot and clean burn inside the firebox. When the inducer kicks in my stack goes to 450-500 depending on what wood I loaded. The ash is hot and warms the house quick and the red and white oak is cooler but leaves hot charcoal chunks almost twice as long.

My old stove was the same, hot as hell inside or cold, no in between. I added some homemade secondary air tubes and was able to extend the times a little and make it more even.

 

[Lawson111]

Looks like I’m just going to have to buy more firewood next year lol. Actually thinking about getting rid of the shelter and getting a pre EPA central boiler. You can still find some pretty decent ones floating around my area.

 

[Medic21]

Looks like I’m just going to have to buy more firewood next year lol. Actually thinking about getting rid of the shelter and getting a pre EPA central boiler. You can still find some pretty decent ones floating around my area.

Glad I don't have to buy it. What are your circulatory blower temp settings. I adjusted mine from 150 on to 170 on and off at 90 instead of 100. Doesn't run as often but runs longer and seems to do a better job kicking on at a higher temp. My old one didn't kick on till 200 then never shut off till time to reload. When I added the secondary air tubes it ran hotter and cleaner with longer times. It was really easy to build and install if you have a drill press and a metal hole saw. You might want to consider going to an EPA certified shelter, My heat is more efficient with the EPA stove but, not as constant as its more like my gas stove in cycling on and off. I made the change to save wood, I offset the environmental savings every time I run my diesel lol.

I'm ready for this sub zero crap to be done tomorrow, a lot less wheelbarrow trips from the leantoo to the house.

 

[laynes69]

Glad I don't have to buy it. What are your circulatory blower temp settings. I adjusted mine from 150 on to 170 on and off at 90 instead of 100. Doesn't run as often but runs longer and seems to do a better job kicking on at a higher temp. My old one didn't kick on till 200 then never shut off till time to reload. When I added the secondary air tubes it ran hotter and cleaner with longer times. It was really easy to build and install if you have a drill press and a metal hole saw. You might want to consider going to an EPA certified shelter, My heat is more efficient with the EPA stove but, not as constant as its more like my gas stove in cycling on and off. I made the change to save wood, I offset the environmental savings every time I run my diesel lol.

I'm ready for this sub zero crap to be done tomorrow, a lot less wheelbarrow trips from the leantoo to the house.

I would lower your on temp. The furnace will still put out heat, maybe not at a higher temp, however the blower will run longer during the coaling stage. If I had mine set up at that temp, I would not be able to heat our home overnight, our blower would rarely cycle at the tail end.

 

[Lawson111]

90 and 160 are my fan set points and If I do decide to keep it I don’t want to void the warranty just yet lol. Still got two more years

 

[laynes69]

I was talking about medic. Page 18 of his manual discusses adjustment of the limit control. His setting at 170 on would cause the furnace to run hotter, and possibly consume more wood in the process. 100 off and 150 on is what the manual recommends, I think 90 off and 140-150 on would work better. Lowering the on or off point on a limit is not going to void a warranty. However raising it to a point where it will overheat or damage the unit will.

 

[Medic21]

I was talking about medic. Page 18 of his manual discusses adjustment of the limit control. His setting at 170 on would cause the furnace to run hotter, and possibly consume more wood in the process. 100 off and 150 on is what the manual recommends, I think 90 off and 140-150 on would work better. Lowering the on or off point on a limit is not going to void a warranty. However raising it to a point where it will overheat or damage the unit will.

That is what shelter reccomennded when it left short cycling. Was told to not touch the high limit that cuts off the inducer.

 

[laynes69]

There's 3 settings on a limit control, off, on and limit. You don't adjust the limit, but lowering the on temp allows the blower to kick in more while in the coaling stage, prolonging the amount of heat extracted from the furnace. The higher the on temp, the longer the furnace has to wait to kick on the blower, therefore no heat is being pushed thru the ductwork.

 

[Lawson111]

In regards to the warranty I was talking about the burn tubes

 

[laynes69]

In regards to the warranty I was talking about the burn tubes

Does your furnace have burn tubes? I have 4 tubes and they glow cherry red everyday, every winter since '07 I think, and they are still good as new.

 

[Lawson111]

No burn tubes. Supposed to have a secondary burn chamber but I don’t think it does anything

 

[Medic21]

There's 3 settings on a limit control, off, on and limit. You don't adjust the limit, but lowering the on temp allows the blower to kick in more while in the coaling stage, prolonging the amount of heat extracted from the furnace. The higher the on temp, the longer the furnace has to wait to kick on the blower, therefore no heat is being pushed thru the ductwork.

With this heat wave, 20 degrees out right now, I may try to adjust it some. I was kicking on and only running for 45 sec and then off for a min. They recommended adjusting that. I wish it had a variable speed fan.

 

[KvnSwan]

Have you gotten better burn times yet? I recently bought the shelter sf3100 and havent been overly impressed...im getting 4 hour burn times which is what i was getring with my antique hotblast from tractor supply 10 years ago. Got this one thinking it would be better but hasnt yet made me feel like it was a great decision. When the draft blower kicks on i burn through wood way to fast and if its off its way to cold. I cant find a happy medium at all. Adjusted the draft blower preset damper piece a few times but same results. Also if i pit more than 2 pieces of wood in the shelter the firebox gets cherry red and ill even get some glow at the upper front of the door. The old hotblast i could cram that baby full and not have an issue

 

[laynes69]

Have you gotten better burn times yet? I recently bought the shelter sf3100 and havent been overly impressed...im getting 4 hour burn times which is what i was getring with my antique hotblast from tractor supply 10 years ago. Got this one thinking it would be better but hasnt yet made me feel like it was a great decision. When the draft blower kicks on i burn through wood way to fast and if its off its way to cold. I cant find a happy medium at all. Adjusted the draft blower preset damper piece a few times but same results. Also if i pit more than 2 pieces of wood in the shelter the firebox gets cherry red and ill even get some glow at the upper front of the door. The old hotblast i could cram that baby full and not have an issue

Ouch! Have you measured your draft? Describe your setup, chimney height, size, diameter? Welcome to hearth!

 

[KvnSwan]

Thanks! Im new to all this so im glad i finally found a forum. Ive had trouble finding any sort of feedback or reviews for this shelter. It comes out at 6" from the furnace then i have it t'd up into 8" pipe 15 foot single wall until the tip then i have the double. The temp varries depending on if the draft blower is running. It usually stays steady at 250 degrees. Never has passed 350. If i turn the draft blower off itll drop to 180-200 degrees since its not getting the air from the blower. I would like to get through a night without waking up at 2am freezing my nuts off. Wall thermostat controls the draft blower but has a manual on off also and a 3 speed blower for the warm air. So mostly a) ot would be great to get an extra 2 hours maybe out of it. Get me 6 hours of sleep. And b) the firbox getting so hot with the draft blower on freaks me out. Sometimes if i open the door with 2 or 3 pieces in it the heat shield will be cherry red and looks like ots about to melt in front of my eyes

 

[KvnSwan]

Also the draft blower cover ive been running back at the recomended preset setting which is a 3/8 gap.

 

[brenndatomu]

Sounds like draft is too high...I'd cut the primary air back a bit more...adjust the barometric damper down...or install one if there is none.
Are those temps you listed internal or external pipe temps? If external then that is pretty hot...hotter than need be for sure

 

[3fordasho]

I don't own a Shelter furnace but my goal would be to get adequate heat with out the draft blower running. Reserve it for short runs to start a fire or during a reload. two splits is not going to get adequate secondary burn or heat with out the draft blower running. Check the chimney draft, check your wood moisture content. Any extended runs of the draft blower will result in very short burn times and forge like temps in the firebox. - ie glowing metal parts. The only way two splits works in my Tundra is if there is already a deep coal bed and already hot furnace, then it can work but I would be feeding it every couple hours. The SF3100 has a large 5.7 cuft firebox, you should be getting 8hr+ burns from it.

Try this, go to menards or tractor supply and get a couple bundles of the Redstone or ECO compressed wood bricks. Start a fire in the furnace with 8-10 small splits (2" on a side) and burn it down to a good coal bed. Now load the furnace with 6-8 of the bricks on the hot coals, run the blower for up to 10 minutes to get the bricks charred good, then shut it off. You may have to play with the air inlet but after 15 minutes or so with the blower off you want to quickly crack open the door and hopefully you will see floating flames up near the top of the firebox. Of course this wont last with the door open so you need to take a quick peek. Your goal is to maintain this floating flames (secondary burn) with minimum air coming in and certainly with the draft blower off. If you don't see any flames, you need a bit more air or you didn't char the bricks long enough. The Bricks take the moisture content question out of the equation.

Another use for the draft blower is at the end of the burn cycle when you have nothing left but a bunch of coals - the blower can be run for a bit to burn down the coal bed and get usable heat from them. It also can be used for quick spurts when you need to bump house temps quicker, but I would time limit this or more glowing metal parts (overfire).

These EPA fireboxes need to be loaded pretty full to work properly, my 3.8 cuft tundra takes 5-6 splits- 6" on a side for a full load. I run mine three load cycles a day, full load at 5:30am, 3:30 pm and 10pm. I always have adequate coals for a easy restart but not too many that they get in the way of new wood.

 

[Lawson111]

Try this, go to menards or tractor supply and get a couple bundles of the Redstone or ECO compressed wood bricks. Start a fire in the furnace with 8-10 small splits (2" on a side) and burn it down to a good coal bed. Now load the furnace with 6-8 of the bricks on the hot coals, run the blower for up to 10 minutes to get the bricks charred good, then shut it off. You may have to play with the air inlet but after 15 minutes or so with the blower off you want to quickly crack open the door and hopefully you will see floating flames up near the top of the firebox. Of course this wont last with the door open so you need to take a quick peek. Your goal is to maintain this floating flames (secondary burn) with minimum air coming in and certainly with the draft blower off. If you don't see any flames, you need a bit more air or you didn't char the bricks long enough. The Bricks take the moisture content question out of the equation.[/QUOTE]

This is a really good idea. I am going to try this the next time I have to shut my stove down to clean it. Right now I think I have it running good but there is always room for improvement.

As for burn times it all depends on how much wood I put in and what kind of wood. I can get 4-5 hours out of 4-5 pieces of wood about 6-8" in diameter with cherry and birch and I have been mixing in some beach to help burn longer. I have some beach that I only split in half or left whole and it will burn a lot longer if I load this stove with mostly this or all beach, but it doesn't burn as hot, life 100f cooler. I measure my flue temps with a magnet thermometer its about 16in above the outlet of the stove on black single wall pipe. With the mixed wood I get it to idle around 250-350f. With just beach its around 200-275f.

How much is the dial open on your ash door? I know if mine is open to much my burn temps are way to hot. But I've never seen my stove glow red. So id say your way to hot. I never use my draft blower maybe once and a while to get the fire going faster when I first light it or if there is minimal coals when I re load the stove. I actually just took a wire and jumped the two terminals so I can switch it on and off with the switch and not have it hooked up to a thermostat. I found a good gap on the slide cover of the draft blower and I leave that alone and never change it unless temps outside are -20 and the stove is getting a lot better draft. I do control my burn temps with the bottom ash pan dial I just count how many turns its out and adjust it in or out using the lines on the dial for a reference. For instance when I went to bed last night I set it at 1.25 turns out and it burns around 250-275 to get me through the night and when I loaded the stove up this morning before I left for work I set it at 1.5. Wifey likes the house warm and she's home all day so she can keep the fire going.

Maybe try a manual damper if your flue temps are to high, I know there not recommended but my father had to use one with his old hot blast stove because his draft was to high. I personally install one for my owe comfort, if there is ever a chimney fire I have a way to help stop it or stop it with the damper.

Hope this helps its literally taken my 3 years of adjusting, turning dials, watching flue temps for hours.... to get this stove to burn how I want it haha.

 

[maple1]

Thanks! Im new to all this so im glad i finally found a forum. Ive had trouble finding any sort of feedback or reviews for this shelter. It comes out at 6" from the furnace then i have it t'd up into 8" pipe 15 foot single wall until the tip then i have the double. The temp varries depending on if the draft blower is running. It usually stays steady at 250 degrees. Never has passed 350. If i turn the draft blower off itll drop to 180-200 degrees since its not getting the air from the blower. I would like to get through a night without waking up at 2am freezing my nuts off. Wall thermostat controls the draft blower but has a manual on off also and a 3 speed blower for the warm air. So mostly a) ot would be great to get an extra 2 hours maybe out of it. Get me 6 hours of sleep. And b) the firbox getting so hot with the draft blower on freaks me out. Sometimes if i open the door with 2 or 3 pieces in it the heat shield will be cherry red and looks like ots about to melt in front of my eyes

But what is the total height of your chimney? Say from your furnace outlet, all the way to the very top?

The primary first thing on pretty well any wood burner, is proper draft. And most often overlooked or not fully considered.

EDIT: I'd also be measuring flue temps. With a probe thermometer.

 

[3fordasho]

But what is the total height of your chimney? Say from your furnace outlet, all the way to the very top?

The primary first thing on pretty well any wood burner, is proper draft. And most often overlooked or not fully considered.

EDIT: I'd also be measuring flue temps. With a probe thermometer.

This is the one I like, very accurate at least compared to the magnetic stick on crap:

https://www.teltru.com/p-272-big-gr...ter-lt225r-5-inch-stem-2001000-degrees-f.aspx

Just don't peg it at 1000F, I did that once and then it didn't read right after that.