Might have solved my P68 burn problems...

what Leafmold is writing about is called "overfire air"....air channels up over the fire from the igniter chamber.....theres only two Harmans with this.....The Accentra Insert, and the P68. The rest of the line might have the holes, but they dead end into the stove body. Originally, this post was concerning smoke in the hopper. In the rare instances when we see this, its usually indicative of partial combustion of pellets in the auger tube, prior to the fire.....what happens is a residue gets slowly depisited on the cooler surfaces...its sticky, and accumulates, as well as forming a matrix of fines and a tarry substance inside the auger tube, inside the feeder assembly, on the slide plate, and in the lower portion of the hopper. It'll chug along for a while like this....maybe a couple months, maybe a couple years, until the accumulation gets so heavy that the slide plate seizes and the stove wont feed pellets....sometimes destroying the gearbox on the process. its a pretty big job to clean out, but its possible. Any units we've cleaned we've had to remove, take tot he shop, clean it or replace the feed mechanism, and reinstall the stove. Probably too dirty to do on-site by the stove shop. We've also modified EVERY stove we've done this to, and have yet to see another gum-up on a modified unit. I dont elucidate on the modification, because it does entail drilling of the feeder, etc, and I dont want to see anyone screw up their unit and void the warrantee by doing a "home fix". I also dont want to be liable if they really screw up and have a fire, etc.

Leafmold said:

Most likely your unit is burning better because of the better-than-average cleaning that you accomplished as of late. More people should do what you did (do a thorough job of cleaning their stove). If it makes you feel better thinking you fixed it though, more power to ya!

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These two air ports on either side of auger tube are a design of the burn pot, not feeder assembly. They travel down vertically, into the belly of burn pot. Your probe, when inserted all the way down into these ports, will be seen with a mirror and a good light, deep inside burn pot.
They provide air from the inside of burn pot (belly) to fire area of burn pot, right at the back wall of burn pot, directly above the auger, as per their location. Plug these ports and run stove for a while, and tell me what happens. Smoke in hopper? Lousy flame? Smokey exhaust? 1/2" thick clinkers on the flame guide surface as hard as stone? (left that one out in initial post.)
Regarding these tech. bulletins, they have been discussed in detail on this forum which can be found in a search.
1) tube vent from hopper to auger tube, to address hopper smoke.
2) an extra row of Burn Pot Holes in bottom of burn pot close to auger tube, to address hopper smoke.
Apparently, the new designs address these two service modifications.

I had a serious problem. Hopper full of thick smoke, on an every day basis.
Cleaned these plugged-up-tight ports - no more problem.
I have zero smoke in the hopper now.
I haven't seen a new p68. Have you seen one built in '03? Look at the flame guide. It has a matching recess for these two ports.

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The P68 was not produced in 2003. If your serial number is 003, you have the third stove from the production line. P68's did not come out until 2005. The P68, Accentra insert, and XXV all have the over fire burn pot design. It is designed to driect more flame to the top of the heat exchangers.

Just shut my stove down will see tommorow when I get motivated and see if mine are plugged and whatnot I have been blaming the maeder brothers pellets but maybe these two holes are the culprit have too see I love this site

Interesting topic. I'm beginning to seriously shop around for a new pellet stove and have been leaning toward a Harman P68. My house is only about 1750 sq ft., but I live in upstate, NY and it gets pretty cold in these parts (I live between Utica and Watertown). Anyway, I have a Lopi Fire Fox at present in my living room as secondary heat source (I have a Utica Boiler #2 fuel oil with hot water baseboard as my primary heat source). Given there's one more tax year to claim the maximum $1500 tax credit, and the Lopi is about 15 years old, I figured it's time for a new pellet stove. Reading these posts is giving me second thoughts. Despite this issue, have you all been happy with your Harman stove? Customer service from the company? Dealer? Any help is appreciated.....

Chain said:

Interesting topic. I'm beginning to seriously shop around for a new pellet stove and have been leaning toward a Harman P68. My house is only about 1750 sq ft., but I live in upstate, NY and it gets pretty cold in these parts (I live between Utica and Watertown). Anyway, I have a Lopi Fire Fox at present in my living room as secondary heat source (I have a Utica Boiler #2 fuel oil with hot water baseboard as my primary heat source). Given there's one more tax year to claim the maximum $1500 tax credit, and the Lopi is about 15 years old, I figured it's time for a new pellet stove. Reading these posts is giving me second thoughts. Despite this issue, have you all been happy with your Harman stove? Customer service from the company? Dealer? Any help is appreciated.....

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Really can't complain too much about my P68, only at the end of a second season of use though. Heats my home just fine, both floors, little warmer downstairs than up, have a a fan at top of stairs blowing down on low for circulation, really helps when it is in the teens, when over the upper twenties don't really need it. The stove can eat some pellets though depending on how big your home is and how hot you want it. I use about 1 3/4 bags on the really cold days, maybe a bag and a quarter to a bag and a half the rest of time. Averages out to about a ton a month so far. She does squeak and squeal at times, and give an occasional clunk here and there, but overall it has been two good heating seasons with her. Nothing has failed or needed replacement, but the occasional squeal is becoming a little more occasional lately. Believe it needs and adjustment or some shims in the feeder mechanism. There's lots of post on Harmans, some good, some bad. I wanted a stove with a big hopper for ashes and one that could heat my two floors, I got one. Never really worry about fines, just dump the bag in the hopper and burn away, never a problem yet. That's another plus, the pellet hopper holds 70 pounds of pellets, nice and big. I keep up on the maint. I think that is crucial. So far, happy.

Thanks for the reply, bungalobob. It seems everything I've read in here indicates Harman and Quadrafire are two good choices. I have dealers of both very close to where I live. I can't seem to choose which to go with however. This issue is making me rethink my latest choice of going with a Harman.

I would choose a Harman Hands down over a Quad Mt Vernon AE. I have not had any exp. with the other Quad models. The Harman is a great stove and easy to maintain and work on in the event that something goes wrong. Also replacement parts are readily available and mostily universal for the whole line of Harmans which in turn makes it easier to get and keeps the price down. All harman stoves except the p38 takes the same circuit board at the cost of 185 compaired to 400 for the Quad then you have the multiple sensors and wall control that are all very touch and go. That unit scares me once it is out of warranty

Thanks for your thoughts, rickwa.

As I mentioned in my post above, I have an older Lopi Foxfire that I'm looking to replace. I've never had any problems with it and am going to a Lopi dealer this weekend to check out some new models. I've checked out their website and watched several of the videos provided at the site. Various people around my area swear by their stoves, including my HVAC guy who owns one himself. Anyone on here have any thoughts, experiences, opinions on the Lopi brand? Thanks in advance.

Next time I clean my Mom's P68 I'll have to check those ports. I didn't know what they were.

Tom