Jotul f50

[jeffesonm]

The F50 has a good size firebox and should get you overnight burns. I heat an 1800 sq ft single story home with the F55 and it does a good job, but cannot keep up when it gets into the 20s and below for any extended period. I also have all original 1950s single pane aluminum frame windows, minimal wall insulation, etc...

 

[Knots]

Knots, hope you can figure it out. Keep us posted!

Thanks for the encouragement. Last night, around 8:00, I loaded maple E/W tightly, but not above the fire brick. Opened up the damper and the air, and let it roar to 400. Shut the damper down and the air about 30% open. Around 9:00 I shut the air all the way. I checked it at 9:30 and it was burning nicely.

Woke up this morning at 5:00 and there were enough coals to start a fire easily. The stove surface was at 150. The tell-tale on the surface thermometer told me I saw 625 at some point. It was 9 degrees when I woke up and the house and the basement only lost 2 degrees.

At this point, my theory is that larger splits, mixed with some harder wood like oak and beech, and a small tweak to the air system and this thing will really pump out some heat and burn clean. Gonna be a couple years before my oak is ready, but I have a lot of beech for next winter.

I have some more black birch that is seasoned, but still drying out. I'll try a load of that at some point and see how it goes.

 

[Knots]

I think what you need to do is reduce draft but not with the damper. On the bottom of the stove in the back middle is where the air enters. It's a rectangle hole about 1" X 4" in size. Reduce the opening by 25% and see if that helps. I bet it will. Tune that opening so you can run your stove more like I do.

Search hearth.com for "Florida Bungalow" and you'll find a good explanation of how the EPA designed the certification testing around a 15' chimney. Most people don't have a stack that short.

Wow. This is a great nugget of information.

So that rectangle feeds both the regulated and unregulated air? Am I understanding this correctly?

 

[7acres]

Wow. This is a great nugget of information.

So that rectangle feeds both the regulated and unregulated air? Am I understanding this correctly?

It feeds both primary and secondary burn air. All oxygen supply comes from that rectangle unless you have the door cracked open.

 

[Creekside]

It feeds both primary and secondary burn air. All oxygen supply comes from that rectangle unless you have the door cracked open.

In the manual for our newly installed F55 it has a diagram and shows the primary air coming up through two holes in the front that are directly controlled by the air control lever. If you look underneath the front you'll see what I'm talking about. It also says that rear rectangle is for secondary air and is unregulated.

 

[Knots]

In the manual for our newly installed F55 it has a diagram and shows the primary air coming up through two holes in the front that are directly controlled by the air control lever. If you look underneath the front you'll see what I'm talking about. It also says that rear rectangle is for secondary air and is unregulated.

And so it is. I thought I studied the manual pretty well, but I missed that. I stuck my head under the front of the stove today and saw the sliding plates for the regulated air. Thanks for pointing that out.

 

[Knots]

DISCLAIMER: I am not a wood stove engineer/designer. What I am about to do is technically termed "monkeying-around" with the stove's design. Do so with yours at your own risk.

OK, so here's the monkeying-around I did so far.

The unregulated secondary air slot is four inches wide. I cut a piece of stainless dryer duct tape one inch wide and placed it over the center of the slot. This seemed to provide increased control. I'm still running with the damper closed, but I can keep it from running away.

This morning I cut a two inch piece and placed it over the one inch piece (center half of the slot is covered). This provides even more control. I'm still running with the damper closed, but I can have the primary air slightly off the stop. Stove top is at 600 degrees.

I'm gonna try three inches this afternoon, but I'm a little concerned about the weather influence. It's supposed to go up to 45 with rain this afternoon (yuck).

Here's the one inch strip:

 

[Knots]

That "Florida Bungalow" article was an eye-opener. The stove is designed to meet a short-stack/warm-day situation and I'm running long-stack/cold-day. It all makes sense now.

 

[7acres]

In the manual for our newly installed F55 it has a diagram and shows the primary air coming up through two holes in the front that are directly controlled by the air control lever. If you look underneath the front you'll see what I'm talking about. It also says that rear rectangle is for secondary air and is unregulated.

I learned something new. Thanks for the correction, Creekside!

 

[cybex]

DISCLAIMER: I am not a wood stove engineer/designer. What I am about to do is technically termed "monkeying-around" with the stove's design. Do so with yours at your own risk.

OK, so here's the monkeying-around I did so far.

The unregulated secondary air slot is four inches wide. I cut a piece of stainless dryer duct tape one inch wide and placed it over the center of the slot. This seemed to provide increased control. I'm still running with the damper closed, but I can keep it from running away.

This morning I cut a two inch piece and placed it over the one inch piece (center half of the slot is covered). This provides even more control. I'm still running with the damper closed, but I can have the primary air slightly off the stop. Stove top is at 600 degrees.

I'm gonna try three inches this afternoon, but I'm a little concerned about the weather influence. It's supposed to go up to 45 with rain this afternoon (yuck).

Here's the one inch strip:

View attachment 149434

Hi Knots- checking in to see where your at by restricting the secondary air supply for longer burn times.

Thanks

Wes

 

[Creekside]

Where do you all put your thermometer? The installer told us to put right in the center of the stovetop, but then the manual says to put in the rear corner of the griddle plate? I find theres about 100-150 degree difference between the spots once it gets going. Is one more accurate?

 

[Batman]

Knots, I have played around with restricting secondary air too. I have a 4 inch or so square piece of sheet metal, with one edge folded 90 deg as a sort of handle. A magnet holds it reliably over the air hole, and it is easily adjusted or removed.
My unscientific experiments have yielded inconsistent results. For the most part, I don't use it, but sometimes its fun to screw around. Keep in mind that the more you restrict the secondary air, the more your stove will act like a smoke dragon.

I have a pipe damper too, btw. I tend to use it much more than the restrictor plate thingy, especially during cold snaps. Mah chimbly is 26 feet. I think my stove manual said not to use a pipe damper, but it does no harm, is inexpensive, and a most welcome feature when the stove starts exploring the nuclear option.

 

[7acres]

Where do you all put your thermometer? The installer told us to put right in the center of the stovetop, but then the manual says to put in the rear corner of the griddle plate? I find theres about 100-150 degree difference between the spots once it gets going. Is one more accurate?

I use an IR thermometer. The hottest part of the stove is always rear center of the griddle where the flue gasses pass by before exiting. If the stove has been rip roaring for 15 minutes it will be 150* hotter than anywhere else on the top. If the load on the right hand side caught first that side will be a couple hundred hotter than the opposite side. On a cold night, I like to let the left, center and right get up to around 550*. The back middle will be almost 700*. Then I start bumping down the air lever to where it want it settled down to for the remainder of the burn.

 

[Knots]

Hi Knots- checking in to see where your at by restricting the secondary air supply for longer burn times.

Thanks

Wes

OK - It was zero out this morning. There were still coals from the prior night's fire. Packed the box N/S with a soft maple on the bottom and black birch on the top. Filled it to the top. Let'er rip until everything was charred and started backing it down. Definitely had more control now, although I still had the flue damper closed.

The 1st pic shows the fire at the height of the burn. This is with the primary all the way to left and the damper held 90 degrees to the chimney. I felt that the secondaries were still too much, so I started adding tape. The 2nd pic is where I stopped. The fire showed a small decrease in secondary action and stayed steady at 600 degrees for almost two hours. No smoke from the chimney.

So, I started that fire at around 5:30 AM, put out a good bunch of heat, and it's 1:20 PM and I'm still burning at 450 degrees.

I'm still not happy about running all the way shut, but at least it's controllable now.

 

[Knots]

Where do you all put your thermometer? The installer told us to put right in the center of the stovetop, but then the manual says to put in the rear corner of the griddle plate? I find theres about 100-150 degree difference between the spots once it gets going. Is one more accurate?

The manual says the rear corner of the Griddle Plate. Not knowing what was the griddle plate, and what wasn't, I had them at the rear corner of the inner rectangle.

After looking at an F50 picture, I reckoned that the griddle plate was really the next rectangle out, so I have them where you see in the pic below. It's about 100 degree difference for my stove. So, my original run to 800 may have been to 700 where Jotul says to measure. It was still too uncontrollable though.

 

[Knots]

Knots, I have played around with restricting secondary air too. I have a 4 inch or so square piece of sheet metal, with one edge folded 90 deg as a sort of handle. A magnet holds it reliably over the air hole, and it is easily adjusted or removed.
My unscientific experiments have yielded inconsistent results. For the most part, I don't use it, but sometimes its fun to screw around. Keep in mind that the more you restrict the secondary air, the more your stove will act like a smoke dragon.

I have a pipe damper too, btw. I tend to use it much more than the restrictor plate thingy, especially during cold snaps. Mah chimbly is 26 feet. I think my stove manual said not to use a pipe damper, but it does no harm, is inexpensive, and a most welcome feature when the stove starts exploring the nuclear option.

Yep, this is where I'll probably end up - with an adjustable secondary. I'm eventually gonna put the OAK on, so at that time I think I'll rig up a slider of some sort.

Even with that little slit, I haven't had a wisp of smoke in 5 hours!

I run with the pipe damper closed and the stove doesn't even seem to notice!

 

[7acres]

Yep, this is where I'll probably end up - with an adjustable secondary. I'm eventually gonna put the OAK on, so at that time I think I'll rig up a slider of some sort.

Even with that little slit, I haven't had a wisp of smoke in 5 hours!

I run with the pipe damper closed and the stove doesn't even seem to notice!

Looks like you've found a solution!

 

[Knots]

Looks like you've found a solution!

Definitely feeling a lot better about the stove. I appreciate your (and everyone else's) help in getting this under control. Especially since it's supposed to be -15 and blustery tonight.

 

[Creekside]

I use an IR thermometer. The hottest part of the stove is always rear center of the griddle where the flue gasses pass by before exiting. If the stove has been rip roaring for 15 minutes it will be 150* hotter than anywhere else on the top. If the load on the right hand side caught first that side will be a couple hundred hotter than the opposite side. On a cold night, I like to let the left, center and right get up to around 550*. The back middle will be almost 700*. Then I start bumping down the air lever to where it want it settled down to for the remainder of the burn.

Thanks that makes sense.

And Knots good to see you've found a solution and sounds like you're getting a great burn out of the stove now.

 

[Millrrr]

Thanks that makes sense.

And Knots good to see you've found a solution and sounds like you're getting a great burn out of the stove now.

Been hunting on Internet for a price of the f 50 and f55 can't find anything....any estimation would be greatly appreciated ...thanks tom

 

[begreen]

I'm still not happy about running all the way shut, but at least it's controllable now.

It's never all the way shut. Some air is always being released for the airwash and the secondaries are unregulated.

 

[Batman]

Been hunting on Internet for a price of the f 50 and f55 can't find anything....any estimation would be greatly appreciated ...thanks tom

Millrr, Check out the thread "Jotul f series stoves..." started on Dec 1. Some good info and someone gives some ballpark prices. No dealer will post prices online. FWIW, three years ago I paid 2k for a floor model f 50.

 

[Millrrr]

Millrr, Check out the thread "Jotul f series stoves..." started on Dec 1. Some good info and someone gives some ballpark prices. No dealer will post prices online. FWIW, three years ago I paid 2k for a floor model f 50.

Thanks for the info batman!...i will check it out!

 

[Knots]

It's never all the way shut. Some air is always being released for the airwash and the secondaries are unregulated.

By "shut", I meant as shut as I'm allowed to get it. I'm at the end of my ability to close the primary. The secondary is regulated by me at this point, using tape.