Harman Accentra insert low heat output

[gfuller40]

Hello all,

I'm a long time lurker and new time poster to the forums - hoping to figure this out before I sell this stove out of frustration!

So here's the story:
I've been running a Magnum Countryside pellet stove insert for the past 2 years (I think it was around 50K + BTU) and a real pain to clean but boy, did it crank out the heat - we used it as our primary heat source in our 1700 sq ft cape and would maintain any temp we set it at, even in the coldest temps here in Maine. Our hearth is centrally located which helps as well. This was accomplished burning the average junk MWP or tractor supply brand wood pellets, which around here are the same thing.

So this year we wanted a stove that was a little easier to maintain/clean and that is more visually appealing - the Accentra insert seemed like the perfect stove for this based on reviews, friends that own them, etc... so I thought, why not? we picked up a used one in great physical shape for $2300 and installed it with a 4" liner all the way up the chimney. I don't have an OAK... yet.
So long story short, the stove is burning the same amount of pellets as my last ($400 stove, purchased used) and putting out MAYBE half the heat if I'm lucky. Last night it dipped into the 20's and the furnace had to kick on and run all night and morning to maintain a temp of 65. I'm burning the same pellets as I was last year in the other stove. The Harman is basically ornamental, like one of those fake electric fireplaces only really expensive and more money to run. The heat it puts out is all on the right side of the stove and luke warm to warm at best. It makes sense that the heat is more prominent on the right side of the stove seeing as that is the side it exhausts on. But maybe something is clogged? I cleaned the hell out of it (or so I thought) when I got it before installation with the exception of the ESP probe and other sensors.

Now for some observations while running:

I run it on room temp, cranked all the way up to 90 or whatever it goes to
Manual or automatic (does not make a difference but usually on auto)
Feed set to 6

Yes - I've read the sticky forum on how these things are supposed to work, though it seems no matter what settings I use, the result is the same.

I get a flame that varies a lot - sometimes it's large for a minute or so, then it settles back down to 3-4" high - very inconsistent - does this all day/night. The flame never comes close to burning 1" from the edge of the burn pot, not even cranked up as high as it will go, it's more like 2-3" back. I scrape, brush this thing 4 times a day.
It seems like it's not feeding pellets fast enough based on this, though if it was feeding them any faster it would probably just burn 3 bags a day and put out slightly more heat than it is now.

Basically, I'm at a loss - I have not done any further diagnostics but I'm going to clean the esp probe tonight (though if this was caked with crap it seems like it would do the opposite and over feed but hey, it's a cheap test - maybe brush out the main exhaust port from the inside as well.

With oil at $1.65/gal this does not make sense and I'd probably sell it for scrap if my wife didn't enjoy the ambiance of a wood burning stove so much.


Pardon my frustration and thank you for any help!

 

[DAKSY]

There are some good videos on the Harman site & even googling for Harman cleaning techniques should help you.
It sure sounds like your unit has a blockage somewhere inside, since you only get minimal heat from one side.
Have you used the small Harman brush to clear the tube behind the ash pan?
Have you removed the medallion & cast iron panels on either side of it & scraped the heat accordion exchanger?

 

[Peterfield]

Ash is a great insulator. Just took out the medallion and plates and there was a layer of ash behind them. Cleaned it all out and the rise in heat output was very noticeable after firing it up again.

 

[alternativeheat]

There are some good videos on the Harman site & even googling for Harman cleaning techniques should help you.
It sure sounds like your unit has a blockage somewhere inside, since you only get minimal heat from one side.
Have you used the small Harman brush to clear the tube behind the ash pan?
Have you removed the medallion & cast iron panels on either side of it & scraped the heat accordion exchanger?

My guess, and it's only a guess, but probably not. A lot of new people to these Accentra's and especially bought used miss those steps.

 

[alternativeheat]

Ash is a great insulator. Just took out the medallion and plates and there was a layer of ash behind them. Cleaned it all out and the rise in heat output was very noticeable after firing it up again.

You had the same issue ?

Hey OT I know : did you end up fly fishing the other day ?

 

[gfuller40]

Thank you all for your responses! I will try and clean the probe and shove a brush and coat hanger into the exhaust ports.. I've always vacuumed them out during cleaning but never ran a brush through them. My concern really is the inconsistent burn rate even in the event that this cleaning helps, it seems like that is still an issue. Is that just the lovely nature of these stoves? Has anyone been able to crank the feed up so high it spills burning pellets over the "ledge"? For such a popular stove I'm finding there are very few resolutions to some pretty common problems.

 

[DAKSY]

Another thing you have to clean is the fines box behind the burnpot & above the auger.
Too much sawdust in there will cause uneven burns as well...
Make sure you reassemble it correctly...

 

[Peterfield]

You had the same issue ?

Hey OT I know : did you end up fly fishing the other day ?

I had the stove on low,and wasn't expecting a lot of heat but only noticed a better heat output after a tear-down cleaning. Yes, I did make it to the pond and there were risers but no takers.

 

[alternativeheat]

Thank you all for your responses! I will try and clean the probe and shove a brush and coat hanger into the exhaust ports.. I've always vacuumed them out during cleaning but never ran a brush through them. My concern really is the inconsistent burn rate even in the event that this cleaning helps, it seems like that is still an issue. Is that just the lovely nature of these stoves? Has anyone been able to crank the feed up so high it spills burning pellets over the "ledge"? For such a popular stove I'm finding there are very few resolutions to some pretty common problems.

Well you have no heat coming out of this thing ! Of course it's supposed to heat, Accentra's don't have a good following because they make no heat, nobody would buy them. But it is not the nature of them to spill pellets out of the burn pot no, that would be a different kind of fault. Still it should make plenty of heat to heat a `1700 sq ft house. Most likely it's not cleaned properly. Have you removed that medallion yet and cleaned behind there as was mentioned earlier ?

 

[gfuller40]

Well you have no heat coming out of this thing ! Of course it's supposed to heat, Accentra's don't have a good following because they make no heat, nobody would buy them. But it is not the nature of them to spill pellets out of the burn pot no, that would be a different kind of fault. Still it should make plenty of heat to heat a `1700 sq ft house. Most likely it's not cleaned properly. Have you removed that medallion yet and cleaned behind there as was mentioned earlier ?

haha - I guess you have a good point there. I have cleaned behind the medallion and the baffles and all of that good stuff although I will say there was very little to no build up behind there. I'll try again. I have not cleaned the exhaust tube but the thing seems to be exhausting quite fine, maybe not enough to make a really hot fire though and feet more pellets? I'll get in there tonight and strip this thing down.

So tell me if I'm off here - air intake comes in through the back of the stove and through the burn pot (sucked by the combustion fan on the back of the unit) the combustion takes place in the burn pot and the exhaust is then directed down through the left and right "exhaust holes" at the bottom of the stove (which I assume join into one) before it hits the combustion turbine and heads out the chimney?

For the disribution - it looks like the intake is at the bottom of the stove, gets blown behind the baffles (behind the medallion) and up and out through the vent at top into the room.

 

[alternativeheat]

Make sure your full airway is clear for the room distribution fan as well. After you have it clean try it in Stove Temp mode Auto Ignition on and turn the distribution fan on high. feed rate around 5. Let us know how you make out.

 

[tonyd]

Check the door gasket. The exhaust tube, bottom left of the stove, goes to the back of the stove,turns right, and ends up near the combustion exhaust fan. .If the brush that came with the stove is not pushed in all the way to the round ring on the end of the brush, you are not all the way in. It is a little fussy to get it in but it does go in that far. The right tube goes straight back. My Accentra has heated my 2800 sq ft house for yrs. You'll figure it out.

 

[Bioburner]

Check those door gaskets. An air leak around them can suck room air into the stove and out the exhaust not benefiting the burn and making for several of the issues your having. I put gasket replacement on top of the list of going through a used stove along with a total tear down and brushing- blasting with high pressure air. A kit is only $10 or so.

 

[Tim_M]

If you have only vacuumed but never brushed the 2 exhaust tubes I'm betting they're full of ash and that's what's causing your issues. It's not possible to clean them thoroughly by vacuuming only, and depending on how long it's been since they were last brushed you could have some significant build up in there. I jam my shop vac into one tube while brushing the other so that any dislodged ash will be sucked out. And as tonyd points out, it's important to make sure that when you're doing the left side tube you push the brush all the way in, until your hand is at the tube opening.

 

[gfuller40]

Holy Sh*t!

You guys were spot on.

I pulled the plates, maybe 1/32 - 1/16" of soot on the back side and the baffles, scraped and vacuumed that off. Turned to stove on with the lid and door open to feel the draft from the right and left ports at the bottom, right was strong, left nothing - plugged the right with a rag and the motor struggled - felt the left port and NO vacuum. I threw a flashlight on it, it was wet, like water coming out of it, if must have been condensation or something. I jammed a coat hanger through it and finally busted the clay like crap that was completely clogging it up and got vacuum, YES! I then shoved my shop vac all the way back in the right port hole and kept ramming the coat hanger through the left (all the way over to the back of the right port) while vacuuming the soot and build up out of it. I fired it up on wide open and it's making at least twice the BTU's. It actually smelled like the first time you crank it up on high for the season with the burnt smelling metal and everything along with the roaring draft in the chimney. I'm very excited and actually like this stove again. I think I will need to get a good brush all the way through and around that bend once I find one and the left port dries out from running it. This is awesome guys, thank you all so much. I think I owe ya'll an offshore shark fishing trip if you're in the area next summer on my boat (seriously).

I also cleaned the ESP probe for the hell of it. Red wire one, and it was pretty darn clean. The left side of the stove had essentially no ash build up due to the fact that it was not taking any exhaust. So simple. I have a tendency to over complicate things. Thanks for setting me straight guys.

 

[DAKSY]

{Thanks for setting me straight guys.}

It's what we do...

 

[alternativeheat]

Awesome !

 

[Peterfield]

When I saw a friend's 52i, he told me how important it was to keep those port channels clear. When I finally bought mine, Harman had modified the 52i and those channels are no longer there.

 

[Luvmesomesamples]

Nice to hear you figured it out! Gotta love the members of this site! I will tell you with the older accentra you do need to scrape the accordion heat exchanger weekly or you will lose a lot of heat output as well. After a cleaning it was hard to keep my family room below 85 on max and by the end of the week it was hard to get it above 73. I often would clean it mid week as well in Jan and feb. it def is a great looking stove but anyone out there shopping spend the extra for the 52i. A lot less maintenance.

 

[gfuller40]

I will keep that in mind about the weekly accordian cleanings - I can see where the ash can provide a good layer of insulation. Fortunately the cleaning is very easy and straight forward (even the port cleaning) the hardest part is waiting for the stove to cool down as it takes time.
I actually had the opportunity to get the 52i for the same price (longer drive) but the research I did on it at the time stated that some features were better, some should have stayed the same. I'm assuming there are two versions of the 52i out there now, one with the ports and one with out?
Either way, I do believe it's still a good stove - and an attractive one. When I said it was putting out twice the heat, it is more like 4x the heat. I left it on stove temp (medium) and woke up to a 80 degree house.

Thanks again guys - this has been a big help and was my last resort before giving up on it or biting the bullet and calling the dealer.

 

[alternativeheat]

I will keep that in mind about the weekly accordian cleanings - I can see where the ash can provide a good layer of insulation. Fortunately the cleaning is very easy and straight forward (even the port cleaning) the hardest part is waiting for the stove to cool down as it takes time.
I actually had the opportunity to get the 52i for the same price (longer drive) but the research I did on it at the time stated that some features were better, some should have stayed the same. I'm assuming there are two versions of the 52i out there now, one with the ports and one with out?
Either way, I do believe it's still a good stove - and an attractive one. When I said it was putting out twice the heat, it is more like 4x the heat. I left it on stove temp (medium) and woke up to a 80 degree house.

Thanks again guys - this has been a big help and was my last resort before giving up on it or biting the bullet and calling the dealer.

When in Doubt: Clean !!

 

[tonyd]

This is what keeps it interesting. I knew you could do it. And if you put the softwood pellets in it, it will burn the pants off you if you get to close. Have fun.

 

[alternativeheat]

This is what keeps it interesting. I knew you could do it. And if you put the softwood pellets in it, it will burn the pants off you if you get to close. Have fun.

And good grade softwoods compared with NEWP will be far less ashy.