Jotul F45 Greenville EPA 2020 stove burning hot

[Ace4059]

I’ve setup my new EPA 2020 Jotul F45 Greenville and have burned it for a little over a week now. I don’t feel as if I have control over it and it’s hard to turn down the fire and control the temperature. I am wondering if it’s burning too hot and I am getting an over fire.

I have 17’ of pipe, burning seasoned oak and have 2 thermometers side by side on the top of the stove in the location the owners manual says. The thermometers do not agree with each other. They cross points at 400° and that’s it. I can’t put the thermometer on the pipe because I have double wall and really do not want to drill into it for the probe thermometer.

I did the dollar bill test on the door seal and it passed. I pack the stove with 8 or 9 prices of oak and start the fire with the top down method. I leave the door cracked until the fire is established, then close the door and start slowing tapering down the air intake over the course of 10-15 minutes.
Once the thermometer on top of the fire box says 300° I close off the air intake completely.

That’s when it really doesn’t do much and acts like the air intake is still about 50% open. The fire keeps building and I’m not really getting the secondary burn at the top with the dancing flames. I did check and yes, the metal plate does slide all the way closed on the bottom of the stove for the air intake. The temperature keeps rising and before I know it all the wood is on fire in the box. The Rutland thermometer says 675+ when it maxes out, maybe close to 700. The cheap no brand name thermometer says 800-900.

Now the owners manual doesn’t state a max operating temperature, it just says if any part of the stove starts glowing, then you have an over fire. While nothing has started glowing, I feel 600+ degrees is too hot and an over fire.

I’ve read on here and tried to use aluminum foil in the two holes behind the air adjustment but it didn’t help as much as I thought it should.

So far the only way I’ve found the way to keep the temperature down in the 400’s is to only put 2-3 pieces of wood in at one time.

Is there any other way I can control the temperature better and dial the air back?

Thanks for any help.

 

[begreen]

What species of wood is being burned? How thick across are the firewood splits?

 

[Ace4059]

Oak
Some smaller 4” splits with about the max of 6” across the splits. All about 17” long.
Usually 8 to 9 pieces completely fill that small firebox.
From what I understand the oak trees have been dead two years and the wood was cut/split and stored outside to season for 12 months.

 

[CentralVAWoodHeat]

Just as a third data point, do you have an infrared thermometer you could check the temp with? A good one can definitely give you a more exact measurement if you have competing stove top thermometers.

If the air lever is working correctly and the door passes the dollar bill test my next thought would be that there is an air leak in one of the seams of the stove.

 

[Ace4059]

Just as a third data point, do you have an infrared thermometer you could check the temp with? A good one can definitely give you a more exact measurement if you have competing stove top thermometers.

Amazon delivered it today. I’ll be able to use it when I get home tonight and fire up the stove.

At least I’ll be able to tell which magnetic thermometer was correct or see how far off in temperature they are.

 

[CentralVAWoodHeat]

Amazon delivered it today. I’ll be able to use it when I get home tonight and fire up the stove.

At least I’ll be able to tell which magnetic thermometer was correct or see how far off in temperature they are.

Glad to hear it-after posting I made an edit to include that my next thoughts go to a possible stove seam leak to explain why you can’t control the fire.

 

[Ace4059]

Here’s a few more questions, can the EPA 2020 stoves be turned down as much as the prior stoves? And how hot is too hot?
What temperature should I be seeing on the hotter side with this stove?

Could the new epa regulated stoves just run hotter since they limit how much you can shut off the intake and maybe this stove is working as intended?

 

[begreen]

Here’s a few more questions, can the EPA 2020 stoves be turned down as much as the prior stoves? And how hot is too hot?
What temperature should I be seeing on the hotter side with this stove?

Could the new epa regulated stoves just run hotter since they limit how much you can shut off the intake and maybe this stove is working as intended?

To maintain control of the fire some need the air to be closed down sooner. Waiting too long heats up the entire mass of the fuel in the firebox causing the wood to outgas all at once. That creates a wood gas bloom that burns very strongly. The solution in this case is to turn down the air as the fire heats up, long before the stove top thermometer indicates a hot stove.

 

[Ace4059]

Some observations…
I used two good sized pieces of wood and two smaller pieces on top and started a top down fire. As soon as the fire was established, I closed off the air intake.
Fire went to 400° Max over the course of an hr.
The Rutland magnetic thermometer and IR thermometer were very close in temperature readings.

Flames were still very active so I put aluminum foil over the two round holes behind the air intake at the front of the stove. Didn’t help much so I placed aluminum foil at the back of the stove covering the rectangular hole for the secondary air intake for the top burners.

Flames died down and started dancing. Firebox dropped to right at 300° and started hovering there with a slow burning fire.

Once the coals were established a few hours later I added four more pieces of wood. Fire box kept cooling off below 300 so I remove the foil covering the rectangular hole at the back of the stove.
Flames then became active as if they were receiving too much oxygen, but settled in nicely once temperatures climbed.

I do not think I have a seal/gasket leaking from this observation/test.

I honestly think with this new EPA 2020 Stove you cannot dial back the air intake as much as you need to.

I think begreen is onto something with me not throttling the stove down fast enough.
I might just have to only load 3 to 4 pieces of wood at a time and throttle it down as soon as the flames are established.

I have not had great secondary burn with this stove. By that I mean flames dancing at the top of the firebox from the secondary burners.

 

[Defiant 3]

People are revisiting the idea of old-fashioned cast stovepipe dampers in their 2020 compliant stoves for this exact reason I've heard. Anyone else finding this?

 

[Kevin Weis]

Those dampers are usually reserved for coal stoves. For coal you want just enough draft to pull out the bad stuff and leave the heat in. For wood it really shouldn't be necessary.

 

[Defiant 3]

The possibility of CO backing up into the room makes cast dampers a total no-no with coal!! One would use a barometric damper w coal. I agree in the past 25 years or so cast dampers have not been necessary, but it does seem that 2020 stoves take in alot of air so..

 

[Ace4059]

I checked on the stove twice throughout the night. Loaded the firebox half full and wood finally all caught about an hr later. Looked at it two hours after loading and the temp of the thermometer went up to around 525-550.

 

[begreen]

The possibility of CO backing up into the room makes cast dampers a total no-no with coal!! One would use a barometric damper w coal. I agree in the past 25 years or so cast dampers have not been necessary, but it does seem that 2020 stoves take in alot of air so..

Correct.

EPA stoves since the 1990s have always admitted a bit of air so that the fire doesn't smolder. Most installations don't need a key damper, but when the flue system height exceeds 25 ft. some stoves will benefit from one.

 

[Ace4059]

If I reduce the air intake by placing the aluminum foil over the extra intake vents/holes, do I have anything Safety related to worry about such as a house fire, carbon monoxide poisoning, etc…
I do have carbon monoxide detectors throughout the house.

 

[kennyp2339]

800-900 is the danger area, 550deg - 700 deg f is cruising zone, figure secondary reburn inside the stove takes place aft of 1,100 deg internal.

 

[begreen]

I would not modify the stove. A 17' flue is perfect. Learn how the stove burns and about closing down the air sooner to reduce a large bloom of wood gas all at once . A flue thermometer is more helpful for determining this than a stovetop thermometer. If possible, load the stove with thicker splits too. This thread may be helpful:

Starting a fire and running an EPA stove

There are 3 instruments shown. A Condar probe thermometer on the double-wall stove pipe. The stovetop temperature on a Sandhill thermometer A digital probe readout for the flue using an Auber AT100 IMHO - the only one that matters is the stove top (2). Because that is what is mostly heating...

www.hearth.com

 

[begreen]

Funny. This is a quote in another thread happening right now:

"Don't know how you could runaway an EPA stove (without gasoline and the door open) with the combustion air as restricted as it is"

 

[Todd]

I have the same stove. Sounds like you may be chasing your thermometers. I like to have my stove top thermometer center front of the middle square but I mostly watch my internal flue probe which is much faster to respond. Probably just need a little more time learning the stove and when to shut down the air. I wouldn’t cover any air intakes til you get a little more familiar with the stove.

 

[MR. GLO]

I would load less wood for a while. Or buy a blower and put it on a remote switch to bring heat down for an hour or so. I would measure the draft sometime down the road but guessing yours would be high. Get an auber probe for double wall. I would try some other wood to get an idea if its just oak. Stuffing any of my past stoves will cause max temp range. Sometimes it doesn't take off to max temp until 1.5 hours later. That's one reason why the auber helps and alert you.

The manual says ...Wait 5 – 10 minutes to re-establish the fire before setting the air controls for the desired heat output and burn time. (If there is at least a 2” thick ember bed when reloading, , it may be possible to close the door and immediately adjust the air control setting).

When you reload and close the door how long in time does it take for your wood to ignite?

 

[Ace4059]

When adding more wood I usually just throw it in and leave the door cracked a minute. Once it catches, close the door and don’t touch the air intake lever which is already tuned all the way down.


I read the thread “starting a fire and running an epa stove” a month ago or so before setting up my stove but it was a good re-read now I have my stove up and going. My take away from that is the magnet thermometer is lagging and don’t wait for it to say 300°+ before shutting down the air.

Yes, I feel as if I am chasing the thermometer with this stove and my take away from this thread is:
1. Don’t pack the stove as full
2. 700° is cruising temp and don’t worry if it’s that hot.
3. Shut down the air faster.
4. Leave the stove as is and don’t tune it with the foil covering the intake holes.

 

[Todd]

I think you can pack the stove full just not with smallish super dry wood. This morning I fully loaded mine with 6 splits of super dry Aspen on top of a pretty good coal bed, shut the door and burned on high til my probe thermometer started moving about 5 min, then turned the air all the way down. The stove top was just about 300. The fire slowed down at first but then gradually built back up and about 1 hour later I have some lazy flame with good secondaries going, STT 650, internal flue temp 600. This should give me a good long burn with enough coals to relight this evening a couple hours before bed.

There are times when I don’t shut it down soon enough and it will burn hotter 700+ stove temp but it settles down within the first 2 hours. Weather also plays a big roll. Last few days we had highs in the teens with gusty winds and snow. I adjusted my loading schedule to about every 8 hours with 2/3 full loads. Draft was much stronger and I still burned on the low setting with similar temps as I’m getting today with a full load but a little warmer weather.

 

[neverstop]

I’ve setup my new EPA 2020 Jotul F45 Greenville and have burned it for a little over a week now. I don’t feel as if I have control over it and it’s hard to turn down the fire and control the temperature. I am wondering if it’s burning too hot and I am getting an over fire.

I have 17’ of pipe, burning seasoned oak and have 2 thermometers side by side on the top of the stove in the location the owners manual says. The thermometers do not agree with each other. They cross points at 400° and that’s it. I can’t put the thermometer on the pipe because I have double wall and really do not want to drill into it for the probe thermometer.

I did the dollar bill test on the door seal and it passed. I pack the stove with 8 or 9 prices of oak and start the fire with the top down method. I leave the door cracked until the fire is established, then close the door and start slowing tapering down the air intake over the course of 10-15 minutes.
Once the thermometer on top of the fire box says 300° I close off the air intake completely.

That’s when it really doesn’t do much and acts like the air intake is still about 50% open. The fire keeps building and I’m not really getting the secondary burn at the top with the dancing flames. I did check and yes, the metal plate does slide all the way closed on the bottom of the stove for the air intake. The temperature keeps rising and before I know it all the wood is on fire in the box. The Rutland thermometer says 675+ when it maxes out, maybe close to 700. The cheap no brand name thermometer says 800-900.

Now the owners manual doesn’t state a max operating temperature, it just says if any part of the stove starts glowing, then you have an over fire. While nothing has started glowing, I feel 600+ degrees is too hot and an over fire.

I’ve read on here and tried to use aluminum foil in the two holes behind the air adjustment but it didn’t help as much as I thought it should.

So far the only way I’ve found the way to keep the temperature down in the 400’s is to only put 2-3 pieces of wood in at one time.

Is there any other way I can control the temperature better and dial the air back?

Thanks for any help.

I've been having similar results. Different stove hearthstone Shelburne, but it loads E/W. (Regardless of load size) load stove, wait for flames to lap the baffle, if cat is active close by pass, start to turn down air in increments, secondaries will start, continue to close down air until secondaries stabilize. Eventually the secondaries get very active and the air is fully closed. The air wash starts igniting as secondaries and the glass gets dark. STT spikes 100+ degrees during this, max depends on the wood load. This happens on cold starts and reloads, but it is more noticeable on reloads. I believe it is because I'm not charring the wood, and it is more noticeable on reloads because flames occur quicker/more intensely.

Last night I re-loaded with 2 large splits (red oak 5'x8"x18"+, white ash 5"x5"x14"). STT was ~275. I left the primary 100% open and by pass open. There were aggressive yellow/orange flames for 10+ minutes (didn't actually keep track) and then all of a sudden the aggressive flames died down significantly and turned darker orange. STT was ~420. At that point I closed the by-pass and started to close down the air until the secondaries were barely lapping the baffle. Eventually the primary was set to 80-85% closed and there were secondaries. It continued like this and then eventually was in the coaling phase.

The fire was much more controllable this time. I'm guessing I wasn't actually charring the wood sufficiently and allowing the massive out gassing to occur. So the large out gassing was being ignited by secondaries and this caused everything to get very hot and uncontrollable. It took much longer than expected to char all surfaces of the wood. I definitely haven't been running the stove in this manor.

The aggressive fire in the beginning was scary, but the STT and flue temp never really got too hot. Flue spiked at 345 on single wall.

 

[Todd]

Another thing the F45 manual states is firewood can be too dry if seasoned more than two years, this could lose some of the lower end efficiency.

These stoves are set up to run on the same system they test on, a 15’ chimney in ideal draft conditions. They also test with 20% moisture certain sized according to firebox sized firewood, either Oak for the EPA cordwood method or Doug Fir EPA crib method. They are also stacked a certain way to allow lots of air flow.

So by looking at this I can assume with my 15% super dry Aspen and a 22’ straight up chimney my stove will probably perform differently than what they tested so I compensated by blocking the two unrestricted primary boost air holes turn down the stove quicker than manual recommends and burn somewhat larger splits packed more tightly together.

 

[Ace4059]

Another thing the F45 manual states is firewood can be too dry if seasoned more than two years, this could lose some of the lower end efficiency.

These stoves are set up to run on the same system they test on, a 15’ chimney in ideal draft conditions. They also test with 20% moisture certain sized according to firebox sized firewood, either Oak for the EPA cordwood method or Doug Fir EPA crib method. They are also stacked a certain way to allow lots of air flow.

So by looking at this I can assume with my 15% super dry Aspen and a 22’ straight up chimney my stove will probably perform differently than what they tested so I compensated by blocking the two unrestricted primary boost air holes turn down the stove quicker than manual recommends and burn somewhat larger splits packed more tightly together.

Are the two air holes you blocked the ones directly behind the air intake lever that slides the plate left and right?