NC-30 Weak Draft

[fhon]

I'm having draft issues with an Englander NC-30. I know there are questions about draft issues are all over this forum but I haven’t been able to figure mine out. A little background: It is attached to a masonry chimney lined with a 6 inch corrugated liner. The top of the chimney is about 20 feed from the floor the wood stove sits on. The house is surrounded by tall trees and is on a hill. Leaving windows open doesn't seem to make any difference, so I think I can rule out any negative pressure issues. The moisture reading on the wood was about 14% and I even have problems with drier wood. I rarely have any issue with down draft and smoke never enters the room when opening the door unless I open it too fast.

I've been able to get the fire going somewhat decently by opening and closing the door until I can get the stove top up to about 700. But even then once the fire is nearing the end and the flue temperature starts to drop the logs end up smoldering and large unburnt pieces are left.

Doing some research I considered "air inversion" as a possible issue, seeing as how any smoke coming from the chimney seems to drop down toward the ground. This happens more so than not. I'm also worried that with the NC-30 being so efficient, the lower temperature gases going up the flue may be amplifying any issue.

Right now, I'm not sure what to do next. The installer told me there shouldn't be any issue with the chimney. I'm not sure I believe that and was considering trying to temporarily extend the chimney to see if there's any difference. Can I jam some extra single wall into the corrugated liner?

 

[begreen]

This does sound like this could be a local air inversion situation. Yes you can get a 4 ft length of 6" air duct and insert the crimped end into the liner. Do this on a calm day so that the temporary extension doesn't fall off.

 

[blades]

Your difficulty might also be outside temps, it hasn't been all that cold yet. This affects your draft a considerable amount. You also are likely experiencing some down drafts outside from your location description which have an bad effect on your flue draft as well. You will likely see a major improvement draft wise once the temps get to hovering in the 30F deg. or less mark. 40-50 deg. evenings are tough for any stove to get drafts running strong quickly.

 

[begreen]

It really depends on the setup. At 40-50F our flue system works fine. No smoke spillage or other issues.

 

[fhon]

Alright, I'll try the temporary extension. Worst case scenario I'll get the girlfriend to sit on the roof and hold it in place. She's the one always complaining about how cold it is I haven't really been burning much yet except on the nights it drops into the 30s. But I had this issue last year as well.

 

[Seasoned Oak]

My draft is almost non existent above 60 deg and my chimney is 30 feet tall. Colder outside temps do wonders for draft strength.

 

[Wormyone]

I will have to agree with the others about the outdoor temps not being cold enough yet. Also if the liner is un insulated it will affect draft as well

 

[brenndatomu]

I've been able to get the fire going somewhat decently by opening and closing the door until I can get the stove top up to about 700. But even then once the fire is nearing the end and the flue temperature starts to drop the logs end up smoldering and large unburnt pieces are left.

That doesn't sound like 14% MC wood. You check it on a fresh split face? Once the stovetop is 700*, you will not have any unburnt wood if it is truly dry. Warm outdoor temps are adding to the problem, all this is JMO of course...

 

[fhon]

Thanks for all the replies!

Of course I was talking the moisture reading wrong. But even after taking the reading on a fresh split I got between 17 and 20%

The liner is insulated. I haven't gotten a chance to try extending the chimney though since it's been really windy and warm.

 

[saichele]

I really have a hard time getting much draft above about 35F. You've got a relatively short stack, and an efficient stove. As you describe it, the smoke is sinking after it comes out the top of the chimney.

Essentially, one way or another, the isn't enough heat going up the stack. Draft is very much like a siphon - you get the air moving up the chimney, and it creates a vacuum and sucks more air in through the stove (or any gaps in your pipe). I guess it's possible you're not burning long/hot enough to get the stack warm (are you getting secondary combustion along the burner tubes?)

I had a Napoleon 1400 with a short stack (about 15') that wouldn't draft well either unless you had a good long burn and got everything warm. Also made creosote like crazy.

Steve

 

[Seasoned Oak]

Its too early and too warm to start burning wood in Pa. I can barely keep my stoker going in this kind of weather and that has fan forced draft and a 30+ foot tall chimney. Will be high 60s and 70s this week.

 

[begreen]

I'm glad you are having a mild October. We still are not burning. May make it to November at this rate.

 

[Seasoned Oak]

Still doing summer stuff. Weekends in the mountains,outdoor cooking ,wood food smoking, pig roast,drinking ect. Did i mention drinking? My good seasoned oak is being used to smoke and cook food these days.

 

[begreen]

Sounds a lot better than my yesterday spent cleaning out gutters. Thursday we got a real heavy dump of rain and I saw the water flying off the roof right over the gutters so I thought I better check them. They were gunked up pretty bad. Oh well, we may bottle up the first batch of hard cider this weekend. That's always fun.

 

[Sushiyummy]

Hi fhon. I'm in PA also and having exactly same problem, have you find any solution yet?

 

[Highbeam]

I am burning my NC30 on 10 feet of single wall and 9 feet of double wall. All interior and all vertical. The outside temperatures recently plummeted and I've had a chance to run the NC one week with temps at 60 and the next week with temps in the teens. Let me tell you, the NC responds very well to draft improvements. The very controllable and snuffable stove became a good EPA no-smoke-possible stove when draft picked up. The stable low setting is much closer to fully closed and the secondaries are the main source of fire when the draft is stronger.

The stove still seems happiest at 650 with blowers on and a boxfan blowing on it.

 

[Sushiyummy]

I was wrong when saying :" having exactly same problem with fhon". My burning good but when I open the door for reload smoke and spark( yes, spark.) come out. Stove top temp 250-300F.

 

[bsruther]

Mine has a 15ft liner through a clay lined chimney filled with roxul. On mild days I have to leave the door open a crack on start up and the overall draft is decent, but I can only get the primary air down to about half.
At 22F this morning, loaded 4 logs on a small bed of coals, closed the door and opened the air. The fire took off a few minutes later and it now seems to draft much better. For my setup, 15ft seems to be perfect.
Haven't used the blower yet and I'd be surprised if I end up using it much at all. Ceiling fans do a much better job of moving the heat around than that noisy insert blower on the old stove.

 

[Sushiyummy]

On my Englander 30-NC, draft look good, burn well, only thing bother me is smoke when open the door for reloading.

 

[Seasoned Oak]

Were definitely into wood stove weather now. Good draft all around. My 3 different EPA stoves all thrive on good draft. Por draft usually means lazy fire and not very clean burn.

 

[El Finko]

Sush-
Crack the door open just a bit and leave it for a minute, then slowly open the door. See if that doesn't solve your puffing problem.

 

[Sushiyummy]

Hi El Finko, Some time smoke not come out right away, but it always come out when I put new split on.

 

[FTG-05]

Sounds a lot better than my yesterday spent cleaning out gutters. Thursday we got a real heavy dump of rain and I saw the water flying off the roof right over the gutters so I thought I better check them. They were gunked up pretty bad. Oh well, we may bottle up the first batch of hard cider this weekend. That's always fun.

Excellent example of First World problems

Got the hearth done, now I need the stove guy to complete my *30-NCH* install this Monday.

My prediction: Record high temps across the entire SE the exact instant it gets installed!




Actually, NOAA is predicting sub 20 (that's a positive number!) for Monday PM and Tuesday AM [ great!

 

[Grisu]

I was wrong when saying :" having exactly same problem with fhon". My burning good but when I open the door for reload smoke and spark( yes, spark.) come out. Stove top temp 250-300F.

Are you down to coals when reloading? I can envision sparks and major smoke spillage only when there is still a good fire going.

 

[Sushiyummy]

Grisu, you're right, sparks and major smoke spillage only when there is still a good fire going. But even I'm down to coals, the smoke from new split come out not up the chimney!