Need some input.

[Creekheat]

Ok so two weeks ago we had our Jotul F55 Installed. 26 ft stack 5ft DW and 21ft class a to the cap. Runs great. BUT, the last few loads it has been running seriously hot. Like 740-760 ST temps. We are using excellent <20% mc seasoned wood.
I reload the stove on a coal bed about 2" deep spread evenly. about 300*. It climbs steady to about 750 and holds. Nothing glowing but my DW stack is too hot to touch.
I hold a box fan on it to drop it instantly but then it just settles back in about 750. This goes for about 1/2 hour and she settles in to about a 600* cruise. Manual says "optimal operating range" is 400-700* I have talked to several people that say it's no biggie but I'm new at this and just trying to do it right. Input?

 

[tarzan]

Sounds normal but you could try shutting the air down sooner to keep it from peaking at 750*

 

[Creekheat]

I was discussing that with my wife this morning actually. Normally I load wait about 10, down to 3/4 and wait about 10, down to half and wait about 10, down to 1/4 and wait about 10 then choke it to about 1/8

I think I will drop my wait times to 5 minutes and then choke it all the way on the bottom end see if that helps. Maybe remove the 3/4 adjustment and go straight to 1/2.

 

[begreen]

Is there a key damper on the flue? Reducing the draft a bit should help bring the top temps down.

 

[Creekheat]

No damper

 

[begreen]

I'd consider adding one for more control if the plan of closing the air down sooner doesn't provide the desired results. If closing down the air sooner does work then be happy.

 

[Creekheat]

I'm gonna give it a whirl. If I do add one my DW pipe the first 5ft to the support box is telescopic. I suppose this would not be an issue?

 

[begreen]

They make a special 6" section with the key damper already installed for double-wall pipe.

 

[Creekheat]

Cool. And it will work with the telescopic? I suppose it will go at the bottom?

 

[begreen]

Yes, right at the flue collar.

 

[Grisu]

I reload the stove on a coal bed about 2" deep spread evenly.

That may be part of your problem. Loading dry wood on a large load of hot coals can lead to rapid outgassing and a potential overfire. What I do is to rake all the coals in the front leaving almost none in the back of the stove. I drop 2 to 3 short pieces E-W (sideways) behind the coals which will give you a level surface with the coals. On that I add more wood N-S until I almost reach the burn tubes. This maximizes the firebox and I can keep more control over the burn. Since I have very good draft I also start closing down the air as soon as the wood has caught fire by maybe a quarter. Your stovetop thermometer will lag the actual firebox temps by quite a margin during those early burn stages. Thus, I use the appearance of the fire as a guide on when I can close the air more. As long as you get good flames in the top of the firebox you are doing fine.

 

[Creekheat]

That may be part of your problem. Loading dry wood on a large load of hot coals can lead to rapid outgassing and a potential overfire. What I do is to rake all the coals in the front leaving almost none in the back of the stove. I drop 2 to 3 short pieces E-W (sideways) behind the coals which will give you a level surface with the coals. On that I add more wood N-S until I almost reach the burn tubes. This maximizes the firebox and I can keep more control over the burn. Since I have very good draft I also start closing down the air as soon as the wood has caught fire by maybe a quarter. Your stovetop thermometer will lag the actual firebox temps by quite a margin during those early burn stages. Thus, I use the appearance of the fire as a guide on when I can close the air more. As long as you get good flames in the top of the firebox you are doing fine.

Good info!

 

[jdp1152]

Throw a few wood pellets in there to burn your coals down a bit

 

[Creekheat]

i went back to talking the coal forward and removing about half of them leaving the back empty. this seems to work much better and now it's back to running great.

 

[Nick Mystic]

You shouldn't have to be removing hot coals from your stove to get a proper burn going without risking an over fire. Besides wasting some good heat you'll find that technique to get old pretty fast if you do it every time you reload. Also, transporting hot coals out of the stove and presumably out of the house is a potentially dangerous task when done a few times a day. As others have mentioned, you can control the temperature by letting your coal bed burn down further before you reload and then being a bit quicker on the draw when you dial back your primary air. When I reload on a hot bed of coals in my Jotul F 600 my wood usually fires off very quickly and I am able to drop my primary air down to 1/2 within a few minutes. If my flame action stays strong I can lower it down to 1/4 in another five minutes or so. You just need to keep an eye on your flames after each decrease in air and if you went too far too soon and the flames start dying back too much it's a simple matter of opening the primary air back up a bit until the flames start climbing. When they are again well established you go back to reducing the primary again. After some time experimenting you'll start to get a good feel for how quickly you can go through this process. Of course, by paying attention to your stove top temperatures during this operation you'll eventually get a good feel for how your stove burns.

 

[Grisu]

i went back to talking the coal forward

You must have cut down some interesting trees there...

 

[Hogwildz]

Try cutting the air all the way low and see if that helps.
At those temps, your not running too hot.
At that stack height, you can prolly cut the air all the way low.

 

[Creekheat]

#facepalm.

 

[tarzan]

Glad you got things back under your control. Once the outside temps get back to normal your draft may also.