Temp on Pipe or Stovetop?

[jeffs]

Have a Napoleon 1900 and struggling to keep it at the right temp. Have a magnetic thermometer on the pipe, and recently bought a second one for the stove top. I'm finding that while it's easy to keep the temp in the best range on the pipe, the stove often runs right at the edge of overfiring.

I had contacted Napoleon on what they suggest for operating range for the stove-top (since this is not listed in the manual). They said 600 is optimum, and should never exceed 700.

Once I get to a stable/mature fire, this thing cruises at 650-700 with the draft control all the way in. (Pipe reads about 325/350). Occassionally the top will hit 725.

I am being very careful with not letting the fire take off too fast, closing it down gradually, and my wood is not over-seasoned/excessively dry, and I am not putting it on a deep/hot coal bed.

Before I got the second thermometer for the stove-top, I just went by the one on the pipe, and never worried about this. The stove would put out a ton of heat, but according the my pipe temp. I was in the best range. Now I'm wondering what the stove-top temp was all that time. Trying to keep the top to 600 is almost impossible. I have read that some guys have modified the draft control to close farther, I am not good at metal fabrication/modification, is this something I should consider? Or am I being paranoid about the temps?

I know there is debate about the accuracy of these magnetic thermometers, I tested them in our oven and they were within 25 degrees of each other.

 

[Wood Heat Stoves]

Measuring the stove temperature and the pipe temperature are for 2 different purposes. The stove temperature is like the speedometer in your car, it tells you how fast you're going. The stove top temperature shouldn't go over about 700 degrees. Measuring it helps you adjust the stoves air control so that it's putting out the amount of heat you need for the conditions. Measuring the pipe temperature helps you make sure the chimney is hot enough for a good draft and to keep creosote build up to a minimum without wasting heat up the chimney. Most chimney thermometers have ranges for the best operation. Some people use a thermometer on both the stovetop and pipe. The magnetic thermometers are not very accurate but they don't need to be, it's just a range to help you adjust the stove properly.

 

[oldspark]

jeffs-I am guessing you must have a very good draft and nice dry wood, have you checked your gaskets on your door to make sure you do not have a air leak? Wood Heat Stoves is right on the money with his post about the temperatures.

 

[jeffs]

jeffs-I am guessing you must have a very good draft and nice dry wood, have you checked your gaskets on your door to make sure you do not have a air leak? Wood Heat Stoves is right on the money with his post about the temperatures.

Old Spark–

I believe I do have good draft.

The wood is pretty dry. It was dead wood that was cut and I bought last fall. I had another batch of wood that had seasoned for over a year, and was very dry. It would take off really fast if I wasn;t careful, but now that I am into this second batch it takes longer to get going, I was hoping it would not get as hot, but the results are the same once the fire gets rolling. I'll get to a steady fire, close the draft control completely, and will get a cruising speed of 650-700.

The gaskets look good, stove was new last fall. Only place I may get a little extra air is around the ash pan hole. There is a trap door there and the coals glow bright over that. But I always make sure that is completely closed, and at this point I have a good layer of ashes over it (haven't emptied in a few weeks), so I think it's pretty well blocked.

I just got off the phone with a guy at the place we bought the stove from, he said I should install a barometric damper on the pipe. THat I'm probably getting too much draft from the chimney (our chimney is around 30'). I have heard of putting a manual in-line damper in the pipe, but not a barometric damper. The thing that concerns me about this is that I had to battle cold-chimney syndrome quite a bit the first couple of months. I have figured out how to deal with that now, but I think a barometric draft might complicate that issue.

I understand that taking temp readings at the two locations are for different purposes, but I can't control them independently. It would have been nice if Napoleon had given me the optimum for the top as well as the pipe. For several months I thought I was ok, but may have been damaging the stove?

 

[begreen]

It sounds like you are doing everything right. This is a willing heater and your temps are not unusual. It you want a bit more control, I would prefer to try a key damper instead of a barometric damper. I don't like the idea of introducing cool air to regulate draft. It may work, but at the risk of greater creosote build up. Given that your setup is close to perfect, I think a simple key damper will dial it in perfectly.

PS: Are you reading the stove top temps directly on top of the stove top? A peak temp of 650-700F is not uncommon with good dry wood in a big steel stove.

 

[jeffs]

Any opinions on the barometric damper suggestion?

I have been reading a little on these and get a lot of mixed reviews.

 

[jeffs]

It sounds like you are doing everything right. This is a willing heater and your temps are not unusual. It you want a bit more control, I would prefer to try a key damper instead of a barometric damper. I don't like the idea of introducing cool air to regulate draft. It may work, but at the risk of greater creosote build up. Given that your setup is close to perfect, I think a simple key damper will dial it in perfectly.

Sorry Be Green, I didn't see your post before I asked for opinions on BPs.

 

[begreen]

No problem, we were posting at the same time. Give the key damper a try. It's inexpensive and should make a nice difference. Mount it about 12-18" above the stove top and at least 6" away from the nearest stove pipe joint. Try it at the 45º for a while and at the fully closed position when it is very cold outside or very windy. See how that works out. Remember to open the damper before opening the stove door to avoid smoke spillage.

 

[jeffs]

No problem, we were posting at the same time. Give the key damper a try. It's inexpensive and should make a nice difference. Mount it about 12-18" above the stove top and at least 6" away from the nearest stove pipe joint. Try it at the 45º for a while and at the fully closed position when it is very cold outside or very windy. See how that works out. Remember to open the damper before opening the stove door to avoid smoke spillage.

Thanks. Sounds like a good idea.
Are the ones you get at places like Tractor Supply okay? Or do yoou get what you pay for?

 

[begreen]

Yes, if this is single-wall pipe, that should be fine. If double-wall pipe, you need a mfg. specific damper made for that type of pipe.

 

[jeffs]

Yes, if this is single-wall pipe, that should be fine. If double-wall pipe, you need a mfg. specific damper made for that type of pipe.

How critical is placement. My vertical pipe (from stove to elbow) is 17".

If I put this 12" up, will only have 5" to first joint.

 

[begreen]

That should work. You just want to be sure that the round damper can do a full 90º rotation without binding on the crimp or retaining screws at the adjacent pipe joint.

 

[Backwoods Savage]

I can agree with the damper. As for the thermometers, please understand these are used for guidelines. Many of them are way off as far as accuracy but it does not sound like you should be too worried. I'm not so sure about that comment about your wood not being "over-seasoned/excessively dry," though. I have yet to find any of that wood. Or perhaps you think we burn excessively dry wood? If so, we've been with a problem for many, many moons that we did not know about. Dry wood rocks!

 

[jeffs]

Well, TSC has already taken down all their wood-burning stock, so went to the big box (Lowe's) and found me a genuine Chinese damper. We'll give it a shot.

Overly dry wood? I don't know... something I heard somewhere, that it burns hotter...

I know the older, more-seasoned stuff would take off a lot faster if I wasn't careful. All black cherry and oak. Sure lights easier!

I know it's better for not causing creosote.

 

[jeffs]

Where do you put a stovepipe thermometer then, after the damper?

 

[oldspark]

Where do you put a stovepipe thermometer then, after the damper?

https://www.hearth.com/econtent/index.php/forums/viewthread/24273/

 

[jeffs]

Installed the key damper last week and fired up the stove.

Still reached temps of 700 with draft control closed as far as possible, and the key damper in closed position. This was after the fire had been burning for over an hour.

Was able to keep it at 600 or less as the fire was going through it's stages, but this took constant careful attention, over a period of an hour or more. What a pain. You can't just load this thing up, close the draft down in stages and let it go. You have to constatntly watch it. And it is very hard to control. Close it a little too much and it starts to die. Open it a little too much, and it climbs past 600 easily. there was no sweet spot. And like I said, even after it had settled down to a mature fire, and thought it was stable, I checked it half an hour later and it was cruising at 700 with everything closed!

While it was at 600, the pipe read 250. So I am right on the edge of being too cool there and getting creosote build-up.

I've about had it with this stove.