Napoleon NPI40 questions

[beau5278]

I came to be the owner of a Napoleon NPI40 after my mother passed a couple years ago,she had the stove installed about 20 years ago but never had much luck getting it burning very well. When I started burning it it seemed to put out decent heat but wouldn't burn long before it started building up pellets. It never seemed like it got enough air,I put a door gasket in it,then I found a screen behind the louvered cover on the intakeg that was clogged with lint. Everything I did made it a little better,this past fall before I started burning it again I cleaned it really good and took the screen out,another improvement. The installer ran the intake down through the old clean out for the fireplace so before Christmas I pulled the stove out again and cut every other louver out of the louvered cover,now I get real heat and the stove will easy burn 25-30 hours without cleaning the pot out.
The next issue is that the pellet feed seems to be feeding slow,last winter I couldn't run the stove much over 8-10 hours without stirring the pellets in the pot up to open the air feed holes,I was burning about a bag of pellets per day burning the stove 22 1/2-23 hours which I figured to be around a 1 3/4 per hour. Now I run the feed higher and I'm getting more heat without screwing with the burn pot and I'm burning about a bag and a half per day,right now and I'm not wasting any pellets and I'm getting more heat per bag of pellets but I feel like I have the stove about maxed out at this point,to me it seems like at 4 to 5 I should be feeding a lot more pellets than I am. The stove is suppose to put out 40000+ btus but with the rate that I'm burning pellets it seems like I would only be getting maybe 20000 btus at the most. Does that sound like a pellet issue? An issue with the pellet feed rate? Or did I possibly open the air intake too much? At this point I very seldom touch the air,I run the air between 3 and 4,I only run it lower when I first light the stove and outside temps are in the high 30s to 40 or so,I have to cut the air down to 2 or so so it's not burning the pellets as fast as they come in. Sorry for the long post.

 

[Mt Bob]

Old style knobs and switches on the control board?

 

[beau5278]

Yea,it's a pre EPA stove with a slider that you control air with manually,a knob numbered from one to 5 for pellet feed and another knob numbered 1 to 5 for convection air.

 

[Mt Bob]

Well,it is an old stove,with old problems. Where to start?lol. OK this might be a bit jumbled,sorry.
Some older units had to have the pot scraped even several times a day.No way around it. Quite some years ago Austroflamm came up with a programming that is a "cleaning cycle". At timed intervals, auger would slow down and combustion fan would speed up, effectively "blowing" ashes and crap out of the pot, burning the chunks into smaller sizes. Many stoves today do this still, it works. No way to upgrade such a thing to yours. As an example,my old Integra you would have to scrape the pot 2 times in 24 hours. With the newer program chip,I can go 3 days.
Your stove has only a simple timer circuit for the auger. They do go bad,and can cause strange problems. They are still readily available and easy to install. You also could try cleaning it inside with contact cleaner.
Don't know if your stove has any "hidden" hard to access passages like some, and, as you cannot easily do a leaf blower cleaning, you might consider air pressure and a rubber mallet next cleaning.
Also make sure the flue/chimney is clean and not restricted. Sometimes, a gradual build up occurs, and a "regular" cleaning helps for a while, sometimes even up to the point the stove almost does not function.If you do not have a pellet flue liner to the top of your chimney, it may help this older unit.
Make sure to remove exhaust blower when cleaning.This way you can from the "blower" forward into the stove. Many people ignore this.
Make sure the motor spins very freely. Lube it if you can. It might even be weak from age, windings insulation deteriorating. New ones are available
And,as I'm sure you know, make sure all gaskets and seals are good.
Yes, I do think your stove would be one that would/could be greatly affected by poor quality pellets.My old Integra prefers highest quality. My Harman will burn anything you dump in it. I even did some testing with those "energy logs",lol!
And,as I'm sure you know,yours is a constant vigil,watching and setting the draft slider, Remember, in most conditions, tall flame means you have less air,short "fast" flames is more air coming in. Taller means more heat,less going out the flue.
OK if I think of anything else,will post. There is the option of buying the parts and upgrading it to the newer NPI45 with electronic controls, but I think the price would be scary,even if the harness is still availible.
Good luck.

 

[beau5278]

I did clean the stove pretty much as you recommended last fall,I really don't think it ever had been cleaned like that,it wasn't terrible but it needed it.I used a rubber mallet on it a couple places,the worst place to access was behind the combustion blower but I could see pretty good through that passage when I was done and it looked ok.I wanted to oil the combustion blower but I didn't really see any place that looked like oiling would help anything. Compared to what it was burning last year,it's ten times better this year and really it is sufficient unless the outside temp goes below 15 or so especially if the wind is blowing. I had started scraping the pot last year,I had found quite a bit of carbon buildup on the inside,that was one thing I did religiously and I really don't mind shutting the stove down daily to empty ashes ans scrape that out,usually I have the stove shut down for less than an hour to do that. I can see from the indicator light for the pellet feed that the stove feeds different rates for different settings,the book says that it will feed between 1 and 5 lbs of pellets per hour,right now I have it running at the highest rate and the light is only out 2-3 seconds between cycles when the auger runs. I know if I turn the pellet feed down to 1 the light is off for 30 or 40 seconds or so between cycles. I'm using the Green Supreme pellets but that is pretty much what everybody around here is selling so I'm not sure the extra expense of finding pellets that might burn better would be worth the extra cost. There is a liner in the chimney but I can only see up it a couple feet they had to offset the pipe by at least six or eight inches to,I did bump the pipe with the mallet a few times last fall and some soot came out but it wasn't ridiculous. Since I opened the louvered cap before Christmas I really haven't had to mess with the air slider that much,I only change it by one or 2 numbers from start to finish and I turn it dow a bit when it first starts then open it more after the ash builds up in the pot a little.

 

[beau5278]

Part of the problem might just be that the house is 70 years old and there's only so much this thing is going to do.