I have the NPS45 which has the digital control board, so I up the air trim all the way up to 5 and the feed trim to the lowest at 1.
This still has not made a difference.
See my thread here if you have the chance:
https://www.hearth.com/talk/threads/napoleon-nps45-cake-forming-in-burn-pot.132234/
OK. Read the thread.
Here's what I can add, not sure if it will help:
1. I agree that the Napoleon pellet stoves are very pellet quality dependent. First year we burned Hamers, and they were great. The stove absolutely positively hated the next batch of Hamers we bought from the very same vendor. Evidently this was a known problem with Hamers that year because the vendor credited us with new bags of pellets for every bag of Hamers we had left in our garage, and for every bag of Hamers that clogged up our stove. Can't complain about it overall but it was a pain to get through that process.
2. Somersets burn well in our stove. O'Malley's burn well but we have to open the damper up to 4 or they clog the pot. Presto Logs burn well too. Turmans burn absolutely immaculately in our stove and put out the best heat. They are a little more pricey- not too much more but a little more- and I can only get them from one supplier in this area. That supplier does not deliver. I don't mind going to get the pellets, loading them up in my truck. I've done it by myself several times- but then I have to factor out and back gas into the price of the pellets. I can buy O'Malley's for less and that vendor literally delivers them to my garage door- and helps me load them in.
3. After some messing around with it, I've found, per above, that our stove likes the damper opened up- a LOT. About the only pellet with which we can close down the damper is Turmans. Otherwise I've made my peace with dumping some heat outside in the name of a clean burn. We can compensate with most pellets by turning the convection/room blower down and letting the exchange tubes hold onto a little more heat.
4. Door gaskets and combustion motor gaskets and even the gasket around the ash pan are crucial. We had to replace our door gasket last year? The year before? It's not difficult but you do need to order the specific Napoleon door gasket.
5. Best source I've found for Napoleon stove parts: Mountain View Hearth Products. They advertise here. Their web site is immaculate and their customer service is awesome. Fast shipping, no hassles. I order combustor motor mount gaskets in multiples. Remember, two is one, one is none. If you have to pull the combustion fan motor to clean or for any reason and you tear the gasket, you're done until you get a new one. We ordered the replacement door gasket from them as well.
6. When you pull the combustion motor, the tendency is to look to and vacuum to your left- out the exhaust pathway. Look to your right as well. The exhaust pathway continues behind your firebox. This part of the pathway got major clogged up when we were trying to burn that particularly ashy batch of Hamers. We have an ash vacuum with a pellet stove cleaning kit. For the Big Clean, I shut the stove down, let it cool completely, and I use a standard Shop Vac with a drywall filter and a drywall bag in it. The pieces parts of the pellet stove cleaning kit fit the Shop Vac hose as well. One part is a rubber plug with a length of not very flexible plastic tubing on it. The plug fits into the hose on either the ash vac or the Shop Vac. The plastic tubing fits into nooks and crannies in the pellet stove. Hubs took this part, went to Big Box Home Improvement Store that sells plastic tubing by the length, and got long piece of flexible plastic tubing that fits over the end of the not so flexible plastic tubing attached to the rubber plug. Follow? Attaching the flexible plastic tubing to the inflexible plastic tubing, then plugging that rubber plug into the Shop Vac hose gives me a plastic tube with suction that I can thread into almost anywhere in the stove guts. It's sort of like giving your stove a colonoscopy, without the scope part.
(There's some imagery for you.) Threading that plastic tube to the RIGHT in the exhaust pathway, up behind the fire box and the fire wall, sucked out an amazing amount of ash and cleared up all problems after that batch of Hamers.
7. My major complaint with the Napoleon is that on the preferred feed setting of 4 (according to the manual, this is the most efficient setting) our stove delivers slightly less than 2 pounds of pellets per hour to the pot. It takes us about 22 hours to burn through a 40 lbs. bag of pellets. That translates to a burn rate of about 1.82 lbs./hour. Using the optimistic estimate of 8500 btu's/pound of pellets as used in the Napoleon NPS40 owner's manual, this means that at 100% efficiency (virtually impossible) we are getting a maximum of 15,470 btu's/hour out of this stove. If we use the 20% +/- factor as listed in the owners manual to adjust for pellet size, it gives us a range of 12,376 btu's/hour to 18,564 btu's/hour. But no pellet stove runs at 100% efficiency, and Wolfe Industry's doesn't list an efficiency rating for the NPS40 as far as I know. (You bet I'll look for that piece of information if I ever buy a pellet stove again.) Popular Mechanics lists the average pellet stove efficiency as 78% to 85%. Applied to our numbers, we are getting a range of 9653 btu's/hour to 15,779 btu's/hour out of this stove at feed setting 4.
Our owner's manual states that the stove is capable of a burn rate of 1 to 5 pounds per hour, and will deliver 8500 to 42,500 btu's per hour. Obviously this is using an 8500 btu's per pound of pellet figure. Extrapolating, I would assume (there's that word) that a feed rate setting of 4 would deliver 4 pounds of pellets to the burn pot, or potentially up to 34,000 btu's/hour out of the stove. If I adjust that number down by the 20% +/- factor (in the minus direction) and then further adjust it down to the lowest efficiency figure given by Popular Mechanics (78%) then I would expect us to get a minimum of 21,216 btu's/hour out of this stove. As you can see from the above numbers, we ain't getting anywhere near that.
The manual does not specifically say that at feed settings 2, 3 and 4 that the auger will deliver the corresponding number of pounds of pellets per hour to the burn pot, but I do not think it's illogical to form that conclusion. It would, in the case of our stove, be inaccurate. Our stove has never delivered 4 pounds of pellets per hour into the burn pot. We have never burned through a bag of pellets in 10 hours. So, taking the manually literally, a feed rate setting of 1 delivers one pound of pellets per hour to the burn pot, and a feed rate setting of 5 delivers five pounds of pellets per hour to the burn pot. And apparently everything in between 1 and 5 does whatever the hell it does. (Can I say "hell" on Hearth.com?) Our stove has settled on a nice, leisurely 1.82 pounds/hour at the preferred feed setting of 4.
We did a study on the duty load of the feed dial rheostat and came to the conclusion, after studying it and some correspondence with the Wolf Industry engineers, that the duty load on that rheostat was correct. The rheostat was turning the auger for the correct amount of time, with the correct interval of time in between turns, for each setting. The auger simply is not delivering 4 pounds of pellets to the burn pot per hour at feed setting 4.
I went back and forth with a customer service rep at Wolfe Industries last December for several emails. He was presenting my observations to the engineers. After a few exchanges, the customer service rep and the engineers just sort of disappeared. I had the impression that they had no further answers/information for me. It is what it is.
So, the other night it was bloody blasted cold in here because we'd been away and we'd left the heat on 50'F. It was nighttime, it was getting colder, and we needed to gain against the increasing cold outside. So I turned the feed up to 5 and let 'er rip. Somewhere in the manual or online, we've read that one should not run this stove on feed setting 5 for more than an hour or you'd risk over-firing it. So I committed to keeping a steady eye on the stove for safety's sake, and not letting it run on high for more than an hour.
We didn't make it for an hour before the burn pot clogged up, even with the damper wide open as far as it would go, at 5.
So that answers that- we can't run this stove on high for any appreciable time without a burn pot clog. Let that go on, and you could build a pellet bridge from an overflowing burn pot into the feed tube, and cause a hopper fire. No thanks.
So, my major complaint is that I do not see how we'd ever get the advertised maximum btu's out of this stove.
That being said, we are out from under manufacturer's warranty. The stove store that sold us this pellet stove has changed hands and no longer carries Napoleon products. Swapping it out now will increase our payback horizon further than is practical for us with our current configuration. Stretching out the payback horizon might make it impossible to achieve before we are out of this residence entirely and on to our retirement residence (in which we've installed a Blaze King Princess wood stove.)
So we work at hanging onto the btu's that it does make, and we work with what we have.
Bonus round- I put hydroponics gardens in the room with the stove, and we grown our own salad veggies all year long. The vegetables love the gentle heat and the breeze created by the convection fan. I also put a clothes rack
at a safe distance from the stove and use that heat and air movement to dry our laundry. We save money by not paying for electricity to run the dryer. We save additional money in heating costs because the dryer is not sucking air we've already paid to heat out of the house, heating it up some more, then dumping it outside through the dryer vent.
And, at the end of the day, it's an economical stove to own and operate. I can tear it down and work on it, my husband can tear it down, work on it and repair it if necessary, and it doesn't burn up a lot of pellets.
Which brings me to a question- is the heat output of a stove a simple matter of btu's per pound of fuel in, btu's out- or do btu's "build up" with heat stored in the stove then radiated out into the room? Is there any way in which a stove makes btu's synergistic?
So, overall, this pellet stove is probably saving us a good deal of money but not all of it is directly due to burning pellets.