To damper or not to damper........

[jwscarab]

Hi, I am a new burner. I have a 3 year old Dutchwest non-cat cast iron stove. It has a spring loaded damper so the damper is either fully open or fully closed. Once the damper is closed, the exhaust goes out a reburner duct on the rear floor of the stove.

My question is it seems I can burn a hotter/get more heat fire from the stove if I leave the damper open and cut down the air vs. leaving the damper closed and turning up the air. My installer also mentioned to just leave the damer open. But the owners manual says to burn with it closed all the time.

Sometimes it seems with the damper closed and the air input open, it still doesnt burn right, just smolders till the log is gone, no dancing flames.

Any suggestions or help is appreciated!! Thanks - Joe

 

[webbie]

Do you know the model number? Is this the same as the current Dutchwest non-cat?

If so, do a forum search on everburn, and you will see a lot of discussion about the burning techniques of that particular stove. One comment I will make is that your installer is completely wrong! The stove is designed to be burned with the damper closed! At least at most times.

Read this:
https://www.hearth.com/econtent/index.php/wiki/Downdraft_Stove_Operation/ and read those other threads.

Also, consider whether your wood is really dry and/or whether your chimney is strong enough????

 

[fbelec]

also forgot to say something about burn it for 45 mins give or take 15 minutes before engaging the damper. get it good and hot.

 

[jwscarab]

Thanks guys! Its a 2479. I am going to feel really stupid here. I have been reading for some time tonight on this site, and have learned TONS about my stove. I guess I didnt even realize that the rumble was the reburner. And I think I have been burning "most" of my fires the last 2 years without even getting that lit. Maybe this stove will work better now that I am leaning what to do - know I need to get it hotter.

Problems I have had - most probably from errors. My ashes get too thick, not coals but ashes. Probably from burning too slow. Also I have not let fire get hot enough to get a bed of coals. I closed the damper almost immediatly.

I will try some of these things, buy a nice "rake" to get rid of the ashes, and hope to have better luck.

Also, I use the blower kit - do you guys think that is a good thing or not???

Bear with me, I am new, and should have "learned" this stuff when I bought the stove!

 

[begreen]

No problem jw, we all need to learn new tricks with a new stove. They each have their own personalities.

What kind of wood are you burning and how dry is it? What is the flue height on this puppy?

 

[jwscarab]

OK, the 6" flu goes out the rear for about 2 feet, then up my chimney. The chimney is 32 feet tall. The home is 6 yrs old and the chimney was built good. It has a 12x9 liner built for an open fireplace. I ran a stainless 6" pipe all the way up and 2ft out the top of the chimney. Put a seal on top for the 6" pipe to poke thru. I believe this is a good setup - costly but good.

I burn mostly hickory, oak, or white ash. It is seasoned but maybe a little wet from elements as I have no wood shed yet.

So last night I get the fire good and hot, plenty of coals. I close the damper - top is 670 - reburner sounds great - I load the stove full and cut the air down for the all night burn. I assume the reburner stayed lit, no idea. This morning the stove top is 250. I spread the coals, throw on a few small peices and get it hot again. I leave for work and its 550 on the top. I have to load it and leave for work, so I close the damper and there is no reburner noise.

So my delima is this - I do overnight burns and one shot all day burns as I need it to burn when I am at work. I didnt have time in the morning to wait till it got hotter, so I left. It will probably burn slow and cold.

And my last but most important question is this - my friend and his wife have a older stove with just a exit pipe and NO exhause damper - and they love it. Why would it be so wrong for me to leave my damper open, and cut the intake air??? I know it is wrong, but why? I like to understand, then I learn. It seems it wont get the benefit of the second burn, BUT at least that way I am guaranteed a hot fire every time. If my reburner does not light, or goes out, I waste wood and dont get heat.

Any thoughts/suggestions? Where am I going wrong? Any thoughts are highly appreciated!!

Thanks - Joe

 

[fbelec]

if you get the secondary burner lit, it will burn hot, clean and you don't have to worry about creosote build up in the chimney. if you burn with out the secondary the stove will work but you are burning with smoke going up your chimney thru out the burn, and you will over time build up creosote and have a chimney fire. you can find out over time by using it but if you get your secondary lit you can burn a little lower air setting the stove will get just as hot and you will have a longer burn. if you have been burning with the damper shut and secondary not lit you might want to check out the chimney to see if there is any build up.

 

[begreen]

Sounds like a mighty stack attached to the stove. Is the flue interior or exterior? Personally I would get up at least 30 minutes earlier and not depend on a fire when I am away until I really knew the stove and how it burns. A wood stove is not an on/off appliance. There are many more variables with wood burning.

The stove is going run best if you stoke it, char the wood, then damper down for reburn. It can be run without the reburn, but will likely burn more wood. Regardless, the stove needs to get hot enough to initiate secondary combustion. Stoking the stove and immediately dampering down will likely turn it into a smoke dragon as the wood smolders. This practice can also lead to creosote build up, especially if the flue is exterior. The risk with a quick departure is not knowing how the fire is burning. There is a lot of variation in burning between different wood and sometimes, even different parts of the same tree. If the new wood is put on hot coals, and then the fire is left to smolder, it may suddenly ignite (actually explode) in a mighty back puff. This can be impressive to say the least and under the worst conditions, dangerous.

 

[jwscarab]

You guys are an awesome amount of help. And thanks for being patient with me. It is amazing that for 2 years I just didnt even understand how the reburn worked - or if it was even on. The manual was weak.

But yes, the stack is probably 32 feet total, thats why I put the full liner in it. It is on an external wall tho.

I pretty much understand much better now how it works, what to do, etc. Yes I was burning a smoke dragon. I clean my pipe myself every year and after my first season, I bet I couldnt drop a 3" ball down the 6" pipe, the top was filled with creosote. Now I know why!!

So now I will make sure the reburn is working before I shut the damper - even if it means getting up early! I also need to pay better attention to my wood - keeping it dry.

I have 2 more questions.

1) if my wood is seasoned for a year but wet from recent rain - I assume this will be a factor in the reburn during the inital load. I need to keep my wood very dry for the reburner to keep temp?? I am going to build a wood shed, but in the mean time I have been lazy to cover my wood all the time.

2) I bought the fan kit to try to get more heat from the stove - not knowing I wasnt getting heat cause I wasnt burning correct.....lol. Now that I have the fan, I would guess I should still use it??? or is there some reason why you would not reccomed it.

 

[jwscarab]

Besides my last post questions, hopefully this is my last for a bit......and most important question....is it possible to get the stove too hot on the startup?? If I open damper, and open air fully and let burn 45 minutes, what keeps the stove from getting too hot and causing damage - is this possible, or even an issue??

Thanks again very much!!

 

[begreen]

Yes, with the right wood, it's quite possible to overfire a stove in 45 minutes.

Usually, with good dry kindling, a stove is ready to be refilled in about 30 min. Then, depending on how hot the stove is and the size of the splits, it takes another ~ 10-15 min. to char the wood before dampering down. If the stove has a really hot bed of coals and the wood is really dry, it could be only 5 min. You have to use your judgment on how the burn is going with each reload.

Note, the reason I asked about the flue, is that this is 50% of the stove system. An uninsulated, exterior stack can cause headaches. You've discovered at least a couple of them, creosote build up & balky stove. By the time the gases get high up that stack they are quite cool and condense, forming creosote. You will need to check that chimney much more frequently. The other thing you have noticed with a big cold stack is that the stove can be balky, particularly until the stack is thoroughly warmed up. This may be what you are experiencing with your morning startups.

Insulating the liner would help you out a bit. It's a PITA now, but will improve performance of the stove.

 

[jwscarab]

OK, so last night I got on the roof and cleaned the flu out. It had more buildup than I expected for a month of burning - although I have been smoking, not burning. After that I take off the rear flu collar and vacuum out the 2 chambers on the rear of the stove either side of the reburner. I also got some "hard crusty chunks" coming out of that area. Seemed more like shale stone than coresote. But I got it all cleaned up and ready to go!!

I added 2 thermomiters - one stove top, one flu pipe. I start the fire, knowing what I am doing now. The stove top goes up to 750 The exit was 600. I was using a little paper, 6 2x4's and 5 1"-2" diameter logs, this was used to get my coal base. After I get the coal base, I moved some coals towards rear, added larger wood with full air for 15 minutes then closed the damper and wella!! The secondary is off and running, and stayed running. The house got up to 74 in no time!! This has not happened so fast before as the stove is in the basement.

This morning, I go to do the same thing as it did burn down overnight. Opened damper and got the coal base, and the temps were more like 650. I added wood, chared it for 15 before I closed damper. It stalled so I opened it, gave it 10 more minutes and closed it, it stayed lit

Now that I know what I am doing, I love this thing!!

BUT - I did notice when I went to close the front door, it barely scrapped the outer shelf as I closed it. That has never happened before. The shelf looked a little bowed up in the center. Did overheat the stove?? If so, this is crazy because there is just too small of a window to get a good lit-off, but without damage. Advice??

I feel I now know much more, and I can use this thing correctly, but I am affraid of overheating now.