Need some help/input with new stove

[fraxinus]

My new Jotul F600 is my first experience with an EPA stove after 32 years with an original VC Defiant, so any input on the following issues will be much appreciated.

Operating temperatures: Like goldfishcastle in the recent 400 - how?? post, I found it difficult to get to the 400 degree break-in temperatures with the thermometer placed in the areas on the stove top Jotul specifies. These corners would quite naturally be the coolest areas of the surface since they are furthest from the center of the fire. Using two thermometers, I found a roughly 125 - 150 degree temperature difference between the center top location and any of the four corner locations; in other words, 400 degrees in the corners equals 525 to 550 in the center - pretty close to the upper 600 degree limit. My inclination is to rely on the hotter, center reading as the actual operating temperature, but what would you reccommend?

Stove pipe temperature: With a thermometer on the stove pipe, I'm finding roughly the same temperature differential as the above. So with a stove surface of 450, I'm not finding a pipe temperature above 300 to 325. If I reduce the temperature to slightly above 400, the pipe temp consistently falls below 300. Does this seem right?

Ash disposal: How deep can the ashes accumulate before performance is affected? How important is it (if at all) to keep the area in front of the front center air source clear?

The stove vents into an interior masonry chimney with an 8x12 flu. I've had no issues with draft at all. Fires start easily, secondary burn kicks in as advertised. Fires have been of relatively short duration in what continues to be a quite mild autumn.

My chief complaint about this stove is the amount of time I'm wasting staring at the flames, but I would welcome any comments, advice, etc. Thanks in advance.

 

[ControlFreak]

Seeing the temperature readings you're getting in the center of your stove, it looks like your wood is well seasoned. If you're getting close to the max temperatures Jotul recommends, then try closing off your draft control a bit earlier. Also, if your stove has a blower, run the blower a bit faster and pull a little more heat out of it.

Generally, the biggest thing you're going to notice is that the new EPA stoves are more finicky when it comes to moisture content. In order to get the extended burn times, they feed the fire with less air, and in order to burn wet wood you need tons of air. In order to get the clean exhaust, they raise the internal temperature of the fire by adding the firebrick all around, with secondary combustion, and moist wood will make it impossible to achieve the internal temps you need. All of this means that it's likely that you'll be frustrated with your new stove if your wood is not below 25% moisture, while your old stove would be quite happy with wood that's running 30% moisture. If you don't have wood that you cut and split last summer, then you'll be fighting moisture problems.

I would advise you to stick your thermometer in the center of the stove where it's hottest and don't bother with wondering about all the other temperatures. All of those different locations typically have a similar temperature profile, but just with different amplitudes.

 

[firefighterjake]

My take on this would be to put the thermometer where Jotul recommends . . . in my own case with the Oslo it recommends one of the corners on the stove top. Yes, there will be some variation in temps . . . for example I've noticed that my wood tends to sit up higher towards the back and rear of the stove due to the way I load it. For this reason, I believe, the temp in the back, right-hand corner is consistently higher than the temps at other points . . . which is also why I have my thermometer there.

That said, I wouldn't sweat things too much . . . I do not believe the temp difference is usually that great, for that long.

To get max temps and efficiency you need time and well seasoned wood. I've already noticed a difference in my wood this year from last year . . . and last year's wood wasn't all that bad . . . just not as good as this year's wood.

If you've read my response to the other thread you know how I bring the temps up . . . basically the first cold start load of the day is to establish a nice bed of coals and get the temps up to the "minimum" levels for me . . . the second load is where I really start to have the Jotul pour out the heat and this year with my wood I'm getting some fantastic secondary action . . . even to the point of being able to close my air all the way (vs. only being able to close it to 1/4 or a little more than closed last year.)

As for the ash . . . ash matters . . . when I clean out my stove I try to keep an inch or two of ash in the bottom. It really seems to help insulate the firebox and put the heat where I want it -- namely into the room.