What's wrong with my Jotul F400

[FireRod]

I just picked up a used Jotul F400 that looks like it is in Great condition. Fired it up for the 1st time and everything seemed okay. Loaded it up after a couple of hours and set it on low. Went out to dinner came home 5 hours later and noticed the glass was almost completely black and what wood that was left in the firebox was pitch black also. What the heck is going on?

 

[begreen]

Incomplete combustion. Wait longer before turning down the air. If this doesn't work then the most likely issue is either weak draft or poorly seasoned wood or a combo of both.

 

[FireRod]

It's definitely not the wood, i burnt the same wood in my previous Jotul 3CB. All my wood is at least 1 year old and kept dry inside a wood shed. As far as draft, I'm using the same pipe but rather than 2 - 45° bends now there is 1 straight pipe.

 

[Ctwoodtick]

Perhaps try being home to see how the stove is behaving until you get this straightened out.

 

[FireRod]

Smart reply!

 

[kennyp2339]

It's definitely not the wood,

Not trying to sound like a smart %^$ but your in NJ, with 1 year hardwood that was split and stacked into a shed during one of the wettest years on record?
I also hale from NJ and have a woodshed, I need a minimum of 2 years of split and stacked in my open woodshed before I can burn any oak or locust.

 

[Ctwoodtick]

Especially with the year we had.

 

[MountainDream]

I had to chuckle at the thought of installing a used stove, firing it up, then leaving the house for 5 hrs. Then I read that you are an experienced burner, but my immediate reaction was a loud chuckle. You must be one of those worry free guys that will live forever.

I don't know about your area, but 1 yr of seasoning is barely enough for pine here in NE GA. Hardwoods are 2 yrs minimum, 3 years to be ideal.

I think you've already gotten good advice on poor draft or wet wood. How tall is your chimney? How tight is your house? (Maybe this particular stove would like to have an outside air kit if your house is tight)

 

[MountainDream]

Also, 1 year in a shed is not as good as 1 year in the sun and wind. Split a piece of wood and check the moisture content at the center.

 

[FireRod]

I do understand what you're saying about the past wet season we had but I've seen the fresh split oak that I stacked in the early spring of last year shrink almost 8" in height at a 6' stack. I also keep some wood in front of my stove (below the ashlip of course) which kind of kiln dries it before it goes into the stove. As I'm reading the manual and I think my problem might be draft related. I may need more height with my chimney above my roof line. This wasn't an issue with the 3CB I previously had but being smaller maybe it was adequate for that stove.

Also, in the manual there is a diagram of the air flow. Is it possible by moving the stove that ash may be impeding this flow? I noticed when I rotated the Smoke Outlet Compl. there was a lot of ash in there which I did remove.

 

[kennyp2339]

I do understand what you're saying about the past wet season we had but I've seen the fresh split oak that I stacked in the early spring of last year shrink almost 8" in height at a 6' stack. I also keep some wood in front of my stove (below the ashlip of course) which kind of kiln dries it before it goes into the stove. As I'm reading the manual and I think my problem might be draft related. I may need more height with my chimney above my roof line. This wasn't an issue with the 3CB I previously had but being smaller maybe it was adequate for that stove.

Also, in the manual there is a diagram of the air flow. Is it possible by moving the stove that ash may be impeding this flow? I noticed when I rotated the Smoke Outlet Compl. there was a lot of ash in there which I did remove.
View attachment 240987

Very good questions, hopefully someone that has the same stove provides some insight.

 

[FireRod]

I have another question. I've noticed the manual suggested temp is between 400° and 600° for operating at optimum efficiency. When I burn at these temps I'm not having the problem of bad combustion and I burn clean. The problem is that as the outside temps go above 30° I'd like to burn much slower and lower as I would over night. If I extend my chimney to have a minimum peak clearance of 2' which I'm short of now will I have better draft that will enable me to burn better at lower rate.

 

[begreen]

It's definitely not the wood, i burnt the same wood in my previous Jotul 3CB. All my wood is at least 1 year old and kept dry inside a wood shed. As far as draft, I'm using the same pipe but rather than 2 - 45° bends now there is 1 straight pipe.

The F3CB drafts much easier than the F400. Describe the flue system in detail including height from the stove top to the chimney cap. Is the Castine connected with the flue collar vertical or rear exit to an elbow and then up?

I have had both stoves and neither are great for overnight burns, but the Castine with care will have some coals in the morning for a restart. Part of this was because I was burning softwood and alder/maple mix. I got my longest burns in the F400 by not emptying the ash pan (so that a good ash bed developed) and turning down the stove air much earlier. Going by stove top temp was throwing me off. When I switched to flue temp (probe thermometer on double wall connector) I got better results. Or go by visuals instead of stove top temp. With some cold starts I was turning down the air as early as 250º stove top, but the flames indicated it was ok to start turning down the air until they got lazy, then let the fire regain strength and turn it down again.

 

[SpaceBus]

I know your fuel is dry as you need it to be, but maybe try a pack of red bricks from tractor supply or some other compressed wood product just to verify. If the stove still continues to act the same way, then you know with 100% certainty that your firewood is at an optimum moisture content.

 

[FireRod]

The F3CB drafts much easier than the F400. Describe the flue system in detail including height from the stove top to the chimney cap. Is the Castine connected with the flue collar vertical or rear exit to an elbow and then up?

I'm coming straight up and out of the roof from the flue collar, no bends. My chimney may be a little on the short side as well as there is a Hemlock tree next to my house. Depending on which way the winds blows the tree can block some the air. I have read the the F400 Castine does burn better with a straight flue collar rather than using a 45° turn pipe.

I have had both stoves and neither are great for overnight burns, but the Castine with care will have some coals in the morning for a restart. Part of this was because I was burning softwood and alder/maple mix. I got my longest burns in the F400 by not emptying the ash pan (so that a good ash bed developed) and turning down the stove air much earlier. Going by stove top temp was throwing me off. When I switched to flue temp (probe thermometer on double wall connector) I got better results. Or go by visuals instead of stove top temp. With some cold starts I was turning down the air as early as 250º stove top, but the flames indicated it was ok to start turning down the air until they got lazy, then let the fire regain strength and turn it down again.

I also had much better burn times with a nice ash bed in my 3CB and whenever I cleaned out the ash pan I tried not to disturb the ash bed. I haven't burnt enough to have an ash bed in the F400 but I assume it will make a difference.

 

[FireRod]

I know your fuel is dry as you need it to be, but maybe try a pack of red bricks from tractor supply or some other compressed wood product just to verify. If the stove still continues to act the same way, then you know with 100% certainty that your firewood is at an optimum moisture content.

Like I said earlier the wood I'm burning created no problem in my other stove. I really don't think my problem is wood related.

 

[SpaceBus]

Like I said earlier the wood I'm burning created no problem in my other stove. I really don't think my problem is wood related.

Then spend $5 to rule it out for sure. Wouldn't you rather potentially solve the issue cheaply? What if you don't need a taller chimney? I don't know about you, but I like to try the cheapest fixes first so I can keep more of my money in my pocket.

 

[MountainDream]

You need 2' above any portion of the roof within 10' .This does not necessarily mean it has to be 2' above the peak. In other words, if the roof has a 12/12 pitch, you would need 12 feet of chimney above the roof assuming no other protrusions nearby. If it's a 5/12 pitch you would need 74" of chimney above the roof.

If you don't have 2' above anything within 10', your install does not meet NFPA standards. You may not care..but your insurance company certainly will if there is a house fire related to the stove.

If you are at or below the recommended chimney height it would be a big help to increase the height of the chimney. I have 30' of pipe and it sucks air like a vacuum

 

[Woodsplitter67]

It's definitely not the wood, i burnt the same wood in my previous Jotul 3CB. All my wood is at least 1 year old and kept dry inside a wood shed. As far as draft, I'm using the same pipe but rather than 2 - 45° bends now there is 1 straight pipe.

Im a little south of you. Wood here in nj doesn't season in a year, especially if its oak which alot of our wood is. The wood may have burned ok in a different but the higher MC of the wood may be affecting your stove performance. You need to get a moisture meter and check you wood

 

[begreen]

I'm coming straight up and out of the roof from the flue collar, no bends. My chimney may be a little on the short side as well as there is a Hemlock tree next to my house. Depending on which way the winds blows the tree can block some the air. I have read the the F400 Castine does burn better with a straight flue collar rather than using a 45° turn pipe.

That's correct especially with a short flue. I needed to move the Castine out further into the room for peace of mind for clearances so ours was setup for rear exit, with an elbow pointing up done with double-wall stove pipe. We have 20' of flue so it drafted well once the temps were below about 48º.

I also had much better burn times with a nice ash bed in my 3CB and whenever I cleaned out the ash pan I tried not to disturb the ash bed. I haven't burnt enough to have an ash bed in the F400 but I assume it will make a difference.

The F400 is a different design and has a different behavior. It's going to be more insistent on dry wood and good draft. Get those right and it performs very well. Test the wood moisture as posted above and have at least 16' of flue on the stove. That should help.

FWIW I tried to run the Castine like the F3CB and it didn't work all that well for me either. It took me about a month to adjust and dial in my daily routine.

 

[FireRod]

Im a little south of you. Wood here in nj doesn't season in a year, especially if its oak which alot of our wood is. The wood may have burned ok in a different but the higher MC of the wood may be affecting your stove performance. You need to get a moisture meter and check you wood

23% split a 4"x4" piece of oak out of this wood shed. Full air circulation all sides and bottom.

 

[Woodsplitter67]

23% split a 4"x4" piece of oak out of this wood shed. Full air circulation all sides and bottom.
View attachment 241015

Thats a little high.. i dont even like burning wood that is 20% I shoot for 18%

That reading also may be off and the reading may be higher than 23% if the split was not checked at room temperature.

My wood sheds are also well vented your really looking at 18 to 24 months untill your ready to burn that wood

 

[FireRod]

Thats a little high.. i dont even like burning wood that is 20% I shoot for 18%

That reading also may be off and the reading may be higher than 23% if the split was not checked at room temperature.

My wood sheds are also well vented your really looking at 18 to 24 months untill your ready to burn that wood

That's what I have to work with. I'm sure it would burn better being lower but 23% isn't all that bad. That's right out of my wood shed not room temperature. Heck, today's humidity is 53%.

 

[begreen]

Nice shed! At 23% it's a little bit on the damp side, but it'll burn. This is what I expected. For a hotter and quicker start, try making a couple 12" long "sleepers" to raise the wood a bit. A 12" long 2x4 split in half works great. The sleepers allow air to get under the splits for a quicker start. On a restart, rake the hot coals to the center front. Then place the sleepers N/S about 6" apart, alongside of the hot coals. Now load your splits E/W on top of the sleepers.

I dug back into some old threads on my starting experience with the F400 that you may find helpful.
https://www.hearth.com/talk/threads/generating-proper-draft-for-jotul-castine.3739
I posted frequently on the Castine from 2006 to 2008.

 

[RandyBoBandy]

23% split a 4"x4" piece of oak out of this wood shed. Full air circulation all sides and bottom.
View attachment 241015

What woodspliter said. And nice looking wood shed.