Over fire on 30 nc?

[Diver1992]

Over fire? Bought a nc 30 due to the many high reviews. Everything I have seen and read is the nc30 runs hot and likes dry wood. I have dry wood and I have been running a auber thermometer for the flue and run it between 300-450 degrees. I have not been able to achieve the heat that I’ve wanted because I feel I’ve been loading e/w with only 3 pieces maybe at most. I decided to try n/s and was able to fit 5 pieces. It started off hotter and faster than I expected and I was af first happy. I achieved what I wanted as far as stt and I shut the air completely off at 400 degrees stt but the secondaries kept my flue temp climbing from 500 (which is when I
am starting to get nervous) to almost 700 and the fire was still roaring from secondaries. So I chimexed my stove and chimney and threw old ash I had to kill the fire. Everything I had is new, the stove the liner and I am worried about over firing everything. My liner is single wall insulated with aluminum casing inside an exterior masonry chimney that’s in bad shape. During the whole ordeal I noticed smoke or steam coming from inside the chimney and I have 2-3 ft of roxwool stuffed inside the damper and the top is insulated as well. So I guess my question is is my liner safe to use again or should I replace it? I plan on getting it inspected at this point

 

[EatenByLimestone]

The stove will be fine. 700 isn’t going to harm that stove.

What do you mean by aluminum casing? What on the chimney is in bad shape? You may have cooked water out of it, but you shouldn’t have had that much water in there. You may have had a chimney fire as I’m not sure 2-3 splits are enough to warm the flue. And that is a recipe for creosote formation . I think it’s a good idea to get an inspection.

 

[Highbeam]

Is your auber a probe meter in the flue or surface temperature measurement?

I don’t even close the loading door until a fresh fire makes 500 flue gas temperatures. Then I run the flue gas temps on my auber up to 900 before cutting back the air to cruise at around 750. STT 600-800.

Class A chimney is rated for 1000 degree flue gas continuously.

 

[moresnow]

My liner is single wall insulated with aluminum casing inside an exterior masonry chimney that’s in bad shape.

Post the make/model liner you have.

 

[Diver1992]

Auber thermometer measures surface temp. So I’m not worried about the stove as I’ve been reading other posts and comments about this stove. I’m worried about the chimney liner at this point. Surface temp got up to 700 so that’s 1400 internal and it kept climbing. I typically run a surface temp of 300-450 sometimes up to 500. I been reading other posts and comments and decided to burn n/s instead of e/w. Took off fast let the wood get charred shut the air all the way once the stove got up to 400. And it just kept going. Flue got up to 600 came down to 532 degrees and maintained there for a few minutes and then the secondaries really started to get intense and I waited so long because I was hoping it would calm down. Eventually said this is enough and threw two chimex and some ash I had nearby as I have two kids and a wife at home. I already called a chimney sweep to come and take a look. Just sucks because it 10 degrees outside and I’m using my propane now. Also high beam are you measuring surface or internal? Because from my understanding the 1000 degrees is for internal temp not surface yes?

 

[Diver1992]

Lime this is what I’m talking about. 316 single wall with 1/2 insulation and the “casing” pipe or outside pipe is aluminum but I thought it was stainless per the salesperson I talked to and bought this from.

 

[NickW]

How tall is the flue? How much and what type of stovepipe is there before the liner? The NC30 is an easy breather, so if you don't control it in time it can really take off.

I hit 820 stt once at the old place with the NC30 before I had a flue probe and damper. I was freaking out but no issues. Internal stove temperature is also not flue temperature.

Secondary combustion starts at 1100 degrees. At the beginning of secondary combustion flue temperature won't be nearly that high. I aimed to keep flue temperature (internal gas temperature, not surface temperature) around 700 degrees and as I controlled that with the damper and air control the stt would rise. Cruising was typically 500-650 stt. Good secondaries, light lazy primary flames when cruising. Real time temperature readings with a flue probe tells you sooner than stt when to start controlling the air.

Stuff it full, control the air, let the secondaries do their job. Maybe you need a damper. The more you close the air, the less that's going up the chimney. My burning got better with the flue probe and damper. Close the doors when the load is charred and secondaries are going, close the air in steps based on what the fire looks like.

 

[begreen]

This could be a case of too strong draft if the liner is very tall. 10º outside temps will increase draft strength due to the increased difference between indoor and outdoor temps.
In that case, a few things will help.
1) adding a key damper to the stove pipe and
2) blocking off the boost (startup) air holes. A magnet or metal tape can be used for this. The boost air holes for the 30-NC are located behind the front legs on the bottom of the stove.
3) load thicker splits with no airgaps between them. Don't load crisscrossed wood or Lincoln log style. The splits should be paralled to each other and fairly tightly packed. This helps slow down the burn.

 

[Highbeam]

Auber thermometer measures surface temp. So I’m not worried about the stove as I’ve been reading other posts and comments about this stove. I’m worried about the chimney liner at this point. Surface temp got up to 700 so that’s 1400 internal and it kept climbing. I typically run a surface temp of 300-450 sometimes up to 500. I been reading other posts and comments and decided to burn n/s instead of e/w. Took off fast let the wood get charred shut the air all the way once the stove got up to 400. And it just kept going. Flue got up to 600 came down to 532 degrees and maintained there for a few minutes and then the secondaries really started to get intense and I waited so long because I was hoping it would calm down. Eventually said this is enough and threw two chimex and some ash I had nearby as I have two kids and a wife at home. I already called a chimney sweep to come and take a look. Just sucks because it 10 degrees outside and I’m using my propane now. Also high beam are you measuring surface or internal? Because from my understanding the 1000 degrees is for internal temp not surface yes?

I listed flue gas temps. Read with an auber probe meter about 18” above the stove.

I have found the nc30 to be very easy to slow down but that doing so makes it smoke. Like all noncats, it likes to run hot.

My chimney is 19’ tall and all vertical. How tall is yours?

I have a key damper for when it’s super cold not because it’s required but I feel I can get more efficiency with a correct draft strength.

 

[Diver1992]

High beam: My chimney is about 23-24 foot tall straight shot so I was already thinking of adding a damper just to help control flue gases. This is my first epa certified stove and learning the secondary combustion has been a learning curve.

Begreen you make a good suggestion on possibly modifying the air holes. Also might I add I have the insert style stove so I do not have legs. The wife wouldn’t let me redo our hearth so I could do a freestanding stove and really get that radiant heat because “it’ll look stupid” lol. Before this happened I could easily get the stove to make the house 75-77 degrees but my flue temps which I use surface temp always floated around 400-450 at peak then gradually go down to 300 where I would rake the coals to the front for awhile and at peak stove top would get to 500. That was loading e/w because the wood I’m using I cut and split to fit my old stove which loved to eat big long pieces.

Maybe I loaded the wood wrong when trying to load n/s and all the gases took off and the stove went nuclear on me. Either way I had no control of it and I do not like that feeling. Maybe a had a small chimney fire but based on what I seen the secondaries were going nuclear and inside the stove was blazing so maybe all that heat from the stove made my flue temps shoot up that high. Either way I’m not using the stove until I get the okay that my liner is in good shape or it needs changed out.

 

[EatenByLimestone]

Have them check the crown too. You shouldn’t be getting so much water into the masonry that it steams out.

 

[Diver1992]

Lime I have tried to patch mortar and the crown over the last few years. I was up there today and found that some of my patching job was breaking off.

 

[begreen]

There are a few good thread here that detail a proper crown installation if it needs repair.

 

[Diver1992]

Wanted to report back. Chimney came back good, crown needs some work that I will address. I want to shout to begreen for his advice, but instead of limiting the primary airflow I put a magnet on the secondary intake which has been my problem. So far so good my flue temps is 455 and I am learning on when to shut the intake air completely down. I bought a damper but I misread what it said so it needs sent back. I truly do believe my problem is an overdraft and to much secondary air problem. Will update as I find things out. You all have been awesome and helpful

 

[Diver1992]

 

[Diver1992]

Wanted to send a quick update on how it looks. Flue temp got up to 496 had me a bit worried but it’s starting to settle out now.

 

[begreen]

Nice secondaries!

 

[Diver1992]

Nice secondaries!

I’ve had those secondaries going non stop for awhile now and they’re not slowing down. Got the house up to 77 degrees and the wife is complaining on how hot it is lmao. I appreciate your advice but I went a different way and seems to be working at the moment.

 

[NickW]

Seeing those photos makes me miss my NC30 at the old house...

I hope the magnet continues to help. With my old setup blocking the air gave me issues as the burn progressed, but I wasn't as tall as you are and had a horizontal run that hurt draft as the temps came down. A damper worked well for me but would be difficult to access with your setup.