Roaring Fire but No Heat

[njWinter]

We have an old, non-certified wood stove. We recently purchased this house and it's under construction so the central heating system is turned off. We decided to see if we could use the wood stove to temporarily heat the house while we are working there. We used dry spruce and it burned nicely but I didn't feel much heat coming off the stove. I expected that we wouldn't heat the whole room with a relatively small load of this soft wood, but I thought I might at least feel some radiant heat on my legs. I stood about 1 inch from the stove and the heat was *barely* noticeable. (I've felt more radiant heat coming off the open fireplace in our old house with a duraflame log.) The only time I felt any heat on my legs was when I opened the doors and stood right in front of the flames. The thermometer on the stove pipe indicated it was hot/in the red (600+.) The fire lasted a few hours and we reloaded a few small logs during the fire, but eventually let it burn out because we were leaving the house unattended. All of the wood burned completely with just a few small coals smoldering when we left. I was freezing for the entire duration of this experiment. Outside temp was about 35F and inside was about the same. Chimney is on the outside of the house. This stove will eventually be removed and it won't be replaced, which is why we don't just go ahead and replace it now, but we were hoping to use it temporarily. Any thoughts? Do we just need to burn way more fuel for a much longer period of time? Or is all the heat going up the chimney? And is this stove junk?

 

[jatoxico]

Looks like a combo coal/wood burner. When burning wood use the upper draft caps not the lower air control.

 

[Socratic Monologue]

It takes a long time (even with a gas furnace) to heat a house from 35F. It takes a while to get the stove itself hot -- there's a fair amount of mass to heat.

Yes, you may have been sending the heat up the flue. Using the stove a few times you could get better at adjusting the air intakes to have a decent burn; burning flat-out isn't very efficient. Unfortunately, stoves take a little practice to use them well.

 

[Seasoned Oak]

IF you are really serious about heating with wood you will eventually get a good EPA certified wood stove. Iv had few of these old smoke dragons and to be honest the wood mileage and burn times are terrible compared to a good epa stove. Heating with wood is not easy so why waste a lot of wood and energy with a poor performing stove. And forget about an overnight burn with those old stoves.

 

[Ludlow]

The colder the inside air temp the more it eats up the radiant effect.

 

[Tar12]

Does this have a blower on it?

 

[jetsam]

Yes, the stove is junk.

Yes, you should be able to heat effectively with it (though probably using 4x the wood that a modern stove would).

You should first make sure it is vented safely before burning it.

Cast iron takes a while to heat up.

Close that bottom air control all the way and leave it shut. Jam some tinfoil in it if it isn't airtight. That is likely the coal air intake that brings combustion air up through the grates. It won't help you to warm up if the stove is pulling unrestricted air through both intakes- you'll blow through a load in a couple hours and most of the heat will be blown right up the flue.

 

[Corey]

Your stove pipe is 600F = all the heat is going up the flue. Get a decent fire going, close the doors and cut the air back some. Since the doors are solid, it's sort of a guessing game as to what is going on inside. -Generally the more you close the air, the hotter the stove will get and the cooler the flue pipe will get - to a point. Then as you keep closing down air, the stove will get cooler, too. That is the point where you have 'control' of the fire - you can open the air back up for more heat, or close it down for less. If you have a damper, you might try closing it a bit too. The whole idea is to give the smoke / flue gas time to transfer heat to the stove / pipe before it goes roaring up the flue and out the cap.

I had a similar 'box' type heater for a few years - wouldn't heat worth a cent until I closed the damper about 50%, then it took care of the whole house fine!

 

[njWinter]

IF you are really serious about heating with wood you will eventually get a good EPA certified wood stove. Iv had few of these old smoke dragons and to be honest the wood mileage and burn times are terrible compared to a good epa stove. Heating with wood is not easy so why waste a lot of wood and energy with a poor performing stove. And forget about an overnight burn with those old stoves.

Thank you Seasoned Oak. That avatar is great. Is that you? I agree with you 1000% about replacing the old stove if we are serious about heating with wood. The problem is, I'm not sold on burning wood, although my other half is. We had the chimney professionally inspected and the short story is that we cannot fit an insulated liner into the old chimney so the inspector recommend not using a wood stove with the existing chimney. I've been considering a pellet stove, in which case we *could* fit an insulated liner into the old chimney, but it's an expense that I haven't committed to because using a pellet stove negates a couple of the advantages of heating with wood. Since the house is not currently occupied, and we are working on it, I was hoping to use the old stove temporarily to get a little heat while working. After the weather turns warmer, the old stove would be removed, and either not replaced, or replaced with a pellet stove if we decide to go that route.

 

[njWinter]

Does this have a blower on it?

Yes, there is a blower, but I have never plugged it in so I don't know if it works. I may have tried if I felt some heat coming off the stove, but I felt virtually no heat.

 

[njWinter]

Your stove pipe is 600F = all the heat is going up the flue. Get a decent fire going, close the doors and cut the air back some. Since the doors are solid, it's sort of a guessing game as to what is going on inside. -Generally the more you close the air, the hotter the stove will get and the cooler the flue pipe will get - to a point. Then as you keep closing down air, the stove will get cooler, too. That is the point where you have 'control' of the fire - you can open the air back up for more heat, or close it down for less. If you have a damper, you might try closing it a bit too. The whole idea is to give the smoke / flue gas time to transfer heat to the stove / pipe before it goes roaring up the flue and out the cap.

I had a similar 'box' type heater for a few years - wouldn't heat worth a cent until I closed the damper about 50%, then it took care of the whole house fine!

Thank you Corey. I was under the impression that we needed to get the chimney hot in order to get a good draft, so I thought a hot stove pipe was a good thing. We had a little smoke in the beginning, which I expected since the chimney was cold, but it did stop smoking, which I presume occurred once the chimney heated up. There is a damper in the stove pipe, but I don't know which is the open position and which is the closed position.

 

[begreen]

Your inspector may not know of all the options for the chimney. There are preinsulated liners, 5.5" liners (and stoves that will work with them). Or, in some cases the old clay liner is busted out to make room for a 6" insulated liner. Were these options discussed?

Is there a tile liner in there now? If yes, what is the ID of the chimney?

 

[njWinter]

Yes, the stove is junk.

Yes, you should be able to heat effectively with it (though probably using 4x the wood that a modern stove would).

You should first make sure it is vented safely before burning it.

Cast iron takes a while to heat up.

Close that bottom air control all the way and leave it shut. Jam some tinfoil in it if it isn't airtight. That is likely the coal air intake that brings combustion air up through the grates. It won't help you to warm up if the stove is pulling unrestricted air through both intakes- you'll blow through a load in a couple hours and most of the heat will be blown right up the flue.

Thank you jetsam. I will take all of your advise regarding the air intake and give it another try. It looks like we had all 3 air intakes open during the fire. Is it that with too much oxygen, the fire burns too quickly and all the heat goes straight up the flue? And I agree that the stove is junk (compared to what's possible with a modern stove.) What I meant was, is this stove just not going to produce any heat at all? Maybe we will get some heat out of it after all, before it hits the scrap yard. Also, we had the chimney inspected, and there were some issues, so we will only be using this stove temporarily, and only while we are at the house working.

 

[njWinter]

Your inspector may not know of the options for the chimney. There are preinsulated liners, 5.5" liners (and stoves that will work with them). Or, in some cases the old clay liner is busted out to make room for a 6" insulated liner.

Is there a tile liner in there now? If yes, what is the ID of the chimney?

Thank you begreen. The chimney is made of cinder block with a clay flue. We had a Level II chimney inspection. Among other things, the written report indicates that "the flue for this wood stove is undersized. The flue must not be smaller than the flue collar of the appliance. The appliance collar is 8 inches. The flue is only 7" x 7". This can cause poor venting of the appliance." The inspector told me that a new liner would have an inside diameter of 6" and that such a liner with the required insulation would not fit inside the existing clay flue. He did mention the possibility of busting out the old clay liner, but said that his company would not do that on this chimney due to the condition of the cinder block. I guess they don't want to be responsible for damaging the cinder block. The "condition" that he's talking about, as far as I can ascertain, is that there are cracks in the parge coat (stucco-like coating) on the outside of the chimney. These cracks seem to correspond with mortar joints in the cinder block, and perhaps they go all the way to the inside of the chimney? The cracks near the top of the chimney above the roof line are very bad, which leads me to believe that water got into the cinder block, or at least behind the parge coat, some time in the past. The inspection was not inexpensive and the inspector seemed to be pretty knowledgeable and has the following certifications: F.I.R.E Certified Inspector, CSIA Certified Chimney Sweep, NFI Master Hearth Professional. Although I will say that he did *not* mention the possibility of a pellet stove. I e-mailed him after the inspection and inquired about it. He told me that even though pellet stoves do not require a chimney, if I am venting a pellet stove into a chimney, the flue would need to be insulated since it is solid fuel.

 

[jetsam]

Thank you jetsam. I will take all of your advise regarding the air intake and give it another try. It looks like we had all 3 air intakes open during the fire. Is it that with too much oxygen, the fire burns too quickly and all the heat goes straight up the flue? And I agree that the stove is junk (compared to what's possible with a modern stove.) What I meant was, is this stove just not going to produce any heat at all? Maybe we will get some heat out of it after all, before it hits the scrap yard. Also, we had the chimney inspected, and there were some issues, so we will only be using this stove temporarily, and only while we are at the house working.

No, you should be able to get that stove hot as heck once you figure it out. It won't be as good as a dedicated wood stove but it will still be a big metal box with a fire in it.

With all the air open all the way (or the door open), the firebox is flooded with air, which comes in just as fast as the flue can take it. The fire makes the flue go faster, and that high volume room temp air cools the firebox greatly. It also makes the house cold because the house takes in that same huge volume of cold outside air.

When you shut the air down to what is needed for the fire, the stove can heat up and the house can too.

I would inspect the chimney myself before using the stove. You'll be using it real temporarily if the house burns down. An unlined, damaged chimney could also be a CO hazard for anyone in the house.

 

[coaly]

The chimney is not undersized enough to cause any issues. An 8 inch round is 50.24 square inches. (radius squared X pi) the radius of 8 inch being 4 X 4 =16 X 3.14 = 50.24. The square flue being 49 square inches.(that is actually better than an 8 X 8 being 64 square inches taking more heat to stay above the critical 250* f. to the top)
Many are reduced to 6 inch round (28.26 square inches) and will work fine if the chimney is straight up and insulated. Not having the full diameter means less capacity, at normal heat output or cruise you're fine.
New codes (ICC) no longer allow "any" reduction in pipe or flue size from stove collar, but the NFPA Standard that codes were adopted from allowed up to 1 inch reduction (1 inch diameter, NOT square inch) so your stove could be installed down to 7 round or 38.46 square inch area chimney when it was installed. That is why this is considered a legal installation. Only the adopted ICC code specifies no reduction at all, as well as all appliances needing to be UL Listed for new installations. Your inspector wasn't inspecting it for a new installation.

The firebrick inside will absorb moisture from the atmosphere when not used for a period of time. This moisture must be evaporated and the BTU used rises out the stack in the form of steam. The first fire or so will not radiate near as much heat as when the bricks are dry.

Don't shake the ash down to keep it clean burning wood. Burn on an inch of ash to slow the fire down. The grates are for coal.

Once the chimney is up to temp, close the pipe damper partially. It should be OPEN when the handle is straight with the pipe. Closed goes across the pipe. You will know if it's not open when starting since it will smoke inside. Always open fully when opening doors.

Closing the pipe damper is a chimney control that affects the stove by reducing the velocity of rising gasses in the chimney, thereby reducing draft.

That stove should heat the house up to 1500 square feet or more.

Run the blower after chimney is up to temp. It is a steel plate (not cast iron) stove that uses radiation from the front and convected heat from convection of heated air in the air chamber from the rear.

 

[begreen]

Thank you begreen. The chimney is made of cinder block with a clay flue. We had a Level II chimney inspection. Among other things, the written report indicates that "the flue for this wood stove is undersized. The flue must not be smaller than the flue collar of the appliance. The appliance collar is 8 inches. The flue is only 7" x 7". This can cause poor venting of the appliance." The inspector told me that a new liner would have an inside diameter of 6" and that such a liner with the required insulation would not fit inside the existing clay flue. He did mention the possibility of busting out the old clay liner, but said that his company would not do that on this chimney due to the condition of the cinder block. I guess they don't want to be responsible for damaging the cinder block. The "condition" that he's talking about, as far as I can ascertain, is that there are cracks in the parge coat (stucco-like coating) on the outside of the chimney. These cracks seem to correspond with mortar joints in the cinder block, and perhaps they go all the way to the inside of the chimney? The cracks near the top of the chimney above the roof line are very bad, which leads me to believe that water got into the cinder block, or at least behind the parge coat, some time in the past. The inspection was not inexpensive and the inspector seemed to be pretty knowledgeable and has the following certifications: F.I.R.E Certified Inspector, CSIA Certified Chimney Sweep, NFI Master Hearth Professional. Although I will say that he did *not* mention the possibility of a pellet stove. I e-mailed him after the inspection and inquired about it. He told me that even though pellet stoves do not require a chimney, if I am venting a pellet stove into a chimney, the flue would need to be insulated since it is solid fuel.

This would work for a 6" outlet stove if the condition of the chimney liner is safe, but it does sound like you need to consider the overall cost of getting things operational. If the chimney is in bad shape, one option would be to remove the chimney completely and replace it with a stainless chimney system. That would provide the safety and best performance, but you still need a better stove to heat well with while not using a ton of wood. Depending on the area needing heat, these can be had for under $1000.

 

[coaly]

Cinder block with a clay flue or cement block? Big difference. Cement block that needs mortar in joints or repointing like bricks is very fixable.

I wouldn't consider your stove junk. Just not as efficient as a newer stove. I would use coal when used as a primary heat source.

Obviously, close the bottom air intake under grates burning wood, open bottom intake for primary air burning coal, and only crack the upper intakes burning coal for secondary air above the fire. It doesn't take much above the fire with coal. Very little only to allow ignition of coal gas above the coal bed. More than a crack allows cooler indoor air to rush into stove and up chimney cooling it, decreasing draft needed for air that must get up through the coal bed from under fire.

 

[Tar12]

Yes, there is a blower, but I have never plugged it in so I don't know if it works. I may have tried if I felt some heat coming off the stove, but I felt virtually no heat.

You may want to consider finding some 1/4 steel plate and cutting it to size to cover the shaker grates...this was my friends fix in a old wood/coal burner he had acquired with a old farm house...in his situation it made a huge difference!

 

[coaly]

You may want to consider finding some 1/4 steel plate and cutting it to size to cover the shaker grates...this was my friends fix in a old wood/coal burner he had acquired with a old farm house...in his situation it made a huge difference!

If you don't shake the grates and let the ash pack solid it is the same as covering with firebrick or metal.
The main thing is not opening the bottom intake to prevent air coming up through the fire.
I'm betting that stove will heat the entire home for $400 a year burning coal when you know how to use it.
That includes a barometric damper.

Every multi fuel design suffers from something burning the other fuel. This one using the angled bricks as a hopper to direct coal to the grate, takes up wood space. And air getting under the fuel burning wood. It is primarily a coal stove.
For wood use , they simply added larger upper air to be used as primary intake with wood. You have to know to close those upper intakes to a crack with coal and close the bottom intake with wood. And install the correct damper for the fuel being used. It is currently set up for wood.

Was the OP possibly leaving the doors open through most of the experiment? With doors open in Fireplace Mode (with spark screen in place) they are not considered a radiant heater. You will get the efficiency of a fireplace.
If fire viewing is necessary, with screen in place, slowly close flue pipe damper until smoke starts to roll in at top. Open slightly until smoke rises out exhaust, retaining as much heat as possible to radiate. The flue damper becomes the only air control.

 

[njWinter]

No, you should be able to get that stove hot as heck once you figure it out. It won't be as good as a dedicated wood stove but it will still be a big metal box with a fire in it.

With all the air open all the way (or the door open), the firebox is flooded with air, which comes in just as fast as the flue can take it. The fire makes the flue go faster, and that high volume room temp air cools the firebox greatly. It also makes the house cold because the house takes in that same huge volume of cold outside air.

When you shut the air down to what is needed for the fire, the stove can heat up and the house can too.

I would inspect the chimney myself before using the stove. You'll be using it real temporarily if the house burns down. An unlined, damaged chimney could also be a CO hazard for anyone in the house.

I don't know if you saw my post above about the Level II chimney inspection, but the main issues were:
1. Flue not insulated, and cannot be insulated.
2. Thimble size could not be determined and should be 12" masonry all around. This is worrisome.
3. Open joints between clay flue tiles (see pics.) This is worrisome. The chimney is on the outside of the building, and there should be a 1" gap between the chimney and the plywood wall sheathing, but I have no way to determine if that gap is there without removing the vinyl siding that butts up to the sides of the chimney. This flue is contained within a cinderblock chimney, so in my mind, it would take a lot for the products of combustion to reach the flammable building materials. But still...
4. Inadequate floor protection. I'm not too worried about this one. (The stove is unlisted which means that there are no formal clearance listings from the manufacturer. For this reason, all clearances must be taken from the IRC or NFPA211 code books.)
5. There are cracks on the outside of the chimney which should be repaired so that more water damage does not occur. The worst cracks are very high above the roof line.

This house was built in 1980 and presumably the chimney and everything related to this stove were as well.

 

[njWinter]

This would work for a 6" outlet stove if the condition of the chimney liner is safe, but it does sound like you need to consider the overall cost of getting things operational. If the chimney is in bad shape, one option would be to remove the chimney completely and replace it with a stainless chimney system. That would provide the safety and best performance, but you still need a better stove to heat well with while not using a ton of wood. Depending on the area needing heat, these can be had for under $1000.

There are actually 2 flues in this chimney. The other flue is attached to the boiler which is in the basement directly below the wood stove. That flue has a stainless steel liner already. We were quoted $13,500 for a new masonry chimney, which is why we are considering our options of completely removing the wood burning appliance, or replacing it with a pellet stove.

 

[njWinter]

Cinder block with a clay flue or cement block? Big difference. Cement block that needs mortar in joints or repointing like bricks is very fixable.

I wouldn't consider your stove junk. Just not as efficient as a newer stove. I would use coal when used as a primary heat source.

Obviously, close the bottom air intake under grates burning wood, open bottom intake for primary air burning coal, and only crack the upper intakes burning coal for secondary air above the fire. It doesn't take much above the fire with coal. Very little only to allow ignition of coal gas above the coal bed. More than a crack allows cooler indoor air to rush into stove and up chimney cooling it, decreasing draft needed for air that must get up through the coal bed from under fire.

It's definitely cinder block.

 

[begreen]

We were quoted $13,500 for a new masonry chimney, which is why we are considering our options of completely removing the wood burning appliance, or replacing it with a pellet stove.

A decent pellet stove is not cheap and will be more maintenance intensive. Make sure you have good supplies of pellets locally.

For comparison, a good sweep should be able to bust out the clay tile and install an insulated stainless liner for $2-3000 depending on the height. A good stove can be had for $600-$1200 depending on how large an area there is to be heated.

 

[njWinter]

If you don't shake the grates and let the ash pack solid it is the same as covering with firebrick or metal.
The main thing is not opening the bottom intake to prevent air coming up through the fire.
I'm betting that stove will heat the entire home for $400 a year burning coal when you know how to use it.
That includes a barometric damper.

Every multi fuel design suffers from something burning the other fuel. This one using the angled bricks as a hopper to direct coal to the grate, takes up wood space. And air getting under the fuel burning wood. It is primarily a coal stove.
For wood use , they simply added larger upper air to be used as primary intake with wood. You have to know to close those upper intakes to a crack with coal and close the bottom intake with wood. And install the correct damper for the fuel being used. It is currently set up for wood.

Was the OP possibly leaving the doors open through most of the experiment? With doors open in Fireplace Mode (with spark screen in place) they are not considered a radiant heater. You will get the efficiency of a fireplace.
If fire viewing is necessary, with screen in place, slowly close flue pipe damper until smoke starts to roll in at top. Open slightly until smoke rises out exhaust, retaining as much heat as possible to radiate. The flue damper becomes the only air control.

First, I want to say that the level of knowledge on this forum is amazing. I have learned so much. I was wondering why this stove seemed to be so large, and yet the firebox seemed to barely hold any wood! I will try all of your advice and hopefully get some heat! Also, the doors were only opened to re-load and to take the pictures. But all of the air intakes were kept completely open, and I'm pretty sure that the flue was kept completely open for the entire experiment, with just a little spinning to see if it made a difference.