First Non-Cat Secondary Combustion Stove

[CleanDiesel]

Good morning everyone. I need some advice about my new stove.

I purchased a WoodPro TS-2000 that was a closeout due to the changing EPA mandates, for a very reasonable price. This stove is for a cabin I'm building that will be a future home. I installed a 15ft Ventis Insulated SS Chimney. I've had a couple small fires to cure the paint. I've burned wood and anthracite coal for years, but this is my first "EPA Non-Cat" stove.

Yesterday, I built a top-down fire with a couple of good sized dry split oak pieces on the bottom firebricks. I left the door cracked for awhile until the fire was roaring, then closed the door and left the air control fully open (pulled out). I started to see some secondary combustion flames at the top of the firebox, but in a couple of minutes, they stop and the fire begins to die out. If I crack the door, even slightly latched, the fire comes right back up. I repeated this process several times, but it seems the stove limits the primary air too much, even with the air control fully open.

I've heard some people drill out the primary air orifice to make it slightly larger, but wouldn't want to do that without knowing more about this new stove technology. My first thought was a draft issue, but I have plenty of draft with the door cracked slightly -- so that makes me think air intake.

Anybody have prior experience with this or a similar stove? Am I doing something wrong?

 

[tadmaz]

Could be some kind of air restriction, intended (EPA) or not intended (draft issue?). 15ft is on the shorter side, but not unreasonable. Really hate to say this, but sounds like your wood is not "dry enough."

 

[Highbeam]

Maintaining that secondary burn requires a hot firebox. Boiling water out of your wood keeps the firebox too cold. Eventually, after the wood boils dry, the firebox will heat up and seem to run away on you so keep an eye on it.

 

[CleanDiesel]

I can't imagine it was a wood moisture issue. I used 2x4 scrap cuts that have been indoors for kindling and the oak has seasoned at least 3 1/2 years and was in my warm & dry basement for winter storage. It sounds dry when you clink two pieces together and is much lighter weight than if it were wet. The ends have cracked from shrinkage. I don't have a moisture meter because every one I've had either doesn't work or doesn't last, but I'm pretty comfortable with seasoning, splitting, and storing wood.

And again, we're talking about the primary air control fully open. If it restricts air that much, how could you ever possibly turn it down?

 

[CleanDiesel]

I forgot to ask....was it maybe the top-down fire is not the best way to startup these new stoves? Perhaps a coal bed is not developed as quick this way? The firebox is quite wide, reasonably deep, but not very high. The manual says to allow a 2" gap between the top of the wood load and the secondary combustion tubes.

I'll try starting a traditional fire tomorrow and see if that works better.

 

[ABMax24]

Sounds like your wood is on the wetter side. In some ways a tube stove is like a cat stove, except the tubes need to be hotter than a cat to achieve proper secondary combustion, and the number one cause of them not getting hot enough is wet wood.

The other option could be that there is a vacuum in the space and it's not getting enough airflow, try opening a window to rule that out.

I also never run a top down fire, I always light a log cabin style fire from the bottom and allow the flames to rise up and engulf the entire stack, this provides enough heat below to keep the secondaries active above.

 

[Highbeam]

Even dry wood still has an MC in the teens. It just can't get any lower in a natural environment. So if you're at 13% MC and 40 lbs of wood that is 5.2# of water which is .6 gallons. According to the interwebs, a full male bladder holds 16 oz so that's more than 4 dudes lined up peeing on your fire!

But wait, there's more! A woodchuck's bladder holds 1.2 ounces. So that 0.6 gallons is like a line of 67 woodchucks dousing your fire. Hey you woodchucks, quit peeing on my wood!

 

[bholler]

I can't imagine it was a wood moisture issue. I used 2x4 scrap cuts that have been indoors for kindling and the oak has seasoned at least 3 1/2 years and was in my warm & dry basement for winter storage. It sounds dry when you clink two pieces together and is much lighter weight than if it were wet. The ends have cracked from shrinkage. I don't have a moisture meter because every one I've had either doesn't work or doesn't last, but I'm pretty comfortable with seasoning, splitting, and storing wood.

And again, we're talking about the primary air control fully open. If it restricts air that much, how could you ever possibly turn it down?

What pipe temps were you running at?

 

[CleanDiesel]

Even dry wood still has an MC in the teens. It just can't get any lower in a natural environment. So if you're at 13% MC and 40 lbs of wood that is 5.2# of water which is .6 gallons. According to the interwebs, a full male bladder holds 16 oz so that's more than 4 dudes lined up peeing on your fire!

But wait, there's more! A woodchuck's bladder holds 1.2 ounces. So that 0.6 gallons is like a line of 67 woodchucks dousing your fire. Hey you woodchucks, quit peeing on my wood!

Ha ha that's a good analogy! But seriously, the stove is designed to burn "dry" wood <20% moisture content. I don't know anybody that's going to buy kiln-dried wood or cut 2 x 4's to heat their house.

 

[CleanDiesel]

What pipe temps were you running at?

I don't have a stove pipe thermometer on there yet. The stovepipe goes up about 28" vertically before the elbow into the wall thimble.

 

[CleanDiesel]

Sounds like your wood is on the wetter side. In some ways a tube stove is like a cat stove, except the tubes need to be hotter than a cat to achieve proper secondary combustion, and the number one cause of them not getting hot enough is wet wood.

The other option could be that there is a vacuum in the space and it's not getting enough airflow, try opening a window to rule that out.

I also never run a top down fire, I always light a log cabin style fire from the bottom and allow the flames to rise up and engulf the entire stack, this provides enough heat below to keep the secondaries active above.

It's not a vacuum issue -- the cabin is still rough-construction -- not yet sealed or insulated yet.

 

[bholler]

I don't have a stove pipe thermometer on there yet. The stovepipe goes up about 28" vertically before the elbow into the wall thimble.

Ok do you have a 15' chimney with 2 90s. Each of those 90s gives enough resistance to account for a loss of 2 to 3 feet.

 

[begreen]

Assume the issue is not with the stove. I can't say I have ever heard anyone drilling out or opening up the primary air orfice on an EPA stove. If anything it usually is someone doing the opposite. An EPA stove like the WoodPro relies on strong draft to pull air through the secondary tubes. Let's assume the wood is good. That brings into question the draft.

Is the flue path straight up through the roof or out the wall and they up? Was 6" stovepipe and chimney used?
Can you post some pictures of the installation and chimney? Maybe we can spot something.

 

[CleanDiesel]

Hi everyone.

Much better experience today! I started a traditional tepee style fire with sticks and kindling, left the door cracked until I had a small coal bed, added a couple larger logs, one at a time, then shut the door. The fire burned well and I was actually able to turn the air control down as the logs burned down, although it was COLD this morning so I mainly ran it open.

I've never had good luck with top-down fires and I guess this stove is no exception! It seems the coal bed is very important prior to closing up the door all the way. I also made sure there was a pathway down the middle of the coals per the manual, which I didn't do yesterday.

Thanks for the suggestions, this will still be a learning experience compared to traditional stoves.

 

[CleanDiesel]

Ok do you have a 15' chimney with 2 90s. Each of those 90s gives enough resistance to account for a loss of 2 to 3 feet.

Yes, that's right. I totally understand the resistance from the elbows but that's the only way I could do it. I wanted a cleanout tee accessible from outside. I need to get a manometer and check the draft, but I haven't noticed any smoke spillage or other issues.

 

[bholler]

Yes, that's right. I totally understand the resistance from the elbows but that's the only way I could do it. I wanted a cleanout tee accessible from outside. I need to get a manometer and check the draft, but I haven't noticed any smoke spillage or other issues.

The symptoms you are experiencing are typical of either wet wood or weak draft. If you are sure your wood is dry enough you probably need to add height to the chimney

 

[jatoxico]

The fire burned well and I was actually able to turn the air control down as the logs burned down, although it was COLD this morning so I mainly ran it open.

You will most likely find that turning down the air on a well established fire will cause the stove top temperature to rise. Add enough air to keep a clean hot fire but reducing primary air will mean less air up the chimney (lost heat) and promotes secondary burn (more heat per stick). There's a balance to be struck but that's how most find it to be.