Fire behind the burn pot of a Harman Accentra FS...

Hi everyone

Here is the update I promised

Thoroughly cleaned and I mean cleaned the entire stove took off door , front panel etc. to get every nook and cranny absolutely free of any dust, creosote etc. got behind and under the air wash hose cleaned all hinges everything that could be cleaned was ... Then
Had the Feeder air crossover tube kit installed by Harman tech
that solved the smoke problem very nicely ... also got yet another flame guide ( this makes 4 ) just to make sure ...
But was still getting flames on the sides at start up for about 20 minutes...
turned stove off and started experimenting with the rope gasket different sizes and in different places...
finally came up with what is working like a charm for my stove...

Here is what I ended up doing
Instead of putting the rope gasket across the top of the flame guide ( which did not work well on my stove )
I took pictures after the horizontal failed and noticed that it had made black spots where I believe the gases or whatever was causing the flames originated it also made the 1st 2 twists on the auger black ... so
I put it vertically behind each side where the flame guide sits on the pot... I ended up using the 3/4" rope gasket
1/2 " initially worked but after it became compressed over time it did not do the job in the long run...
the 3/4 was harder to get in initially but was well worth it nothing moves the flame guide and no flames ... You will need to carefully push it down with a screwdriver to get it in tight... Just work it down slowly when you have both sides of gasket pushed in this flame guide will not move a cm...
I pushed on it with the screwdriver and it would not budge...
actually I was working on this before the tech came but still had the smoke issue ...The rope gasket had taken care of the flames without the air cross over tube kit ... so if you don't mind the smoke ( mine lasted about 20 minutes following start up) you don't need the crossover kit installed... this stopped the flames for over 1 week before the tech came to put the crossover air thing in...

I wanted to see if the air crossover would work without the rope gasket... much to my dismay the flames started so I replaced the rope gasket and no flames and no smoke for 3 days now... YES !!
Have had the stove off and on each day because it was warmer during the day so it would shut down and start up later in the evening... no smoke after initial start up any of the times...

Another thing I would like to mention since having the air crossover thing done the heat coming out is hotter ... I mean my wife used to be able to sit on the stove ( after coming in from the cold ) but now you would burn yourself if you tried to sit on it... you could touch it quickly without getting burnt but never sit on it again
All settings are exactly like we had them before so that is not the difference ... I really think it is burning more efficiently and hotter

I will post some pics to try to explain what I am talking about in this post to help others understand what worked for me... Sorry but I did not get pictures of it after cleaning was complete as I was too tired & excited to turn it back on and see if any of this helped...
Gasket placed vertically


This is the 3/4" that ended up working best 1/2 " & 3/4" Rope gasket


Note these were all same fire don't know why they came different colors in the pics...
oh to have my Harman Accentra2 working properly ...PRICELESS !
Huge Thanks to all who helped and commented & Cozy Barn for explaining to me what was happening with the flames outside the burn pot I would not have kept experimenting once the horizontal gasket was a failure ... this site is filled with awesome people & full of knowledge !
I am off to enjoy my new heat and beautiful flames... Good night !

corkman said:

hi HarmanAccentra2..ive been following you thread for quiet a while..i recently picked up a 2004 accentra and it was having similar issues to yours..i had the flames on both sides of the pot as well as above the flame guide.i was getting constant white smoke exiting the stove and you could see the smoke inside the stove curling around the burn pot..there was also a lot of creosote forming around the pot.i removed the pot and there wasnt much there for a gasket..i wire wheeled the pot to almost new as well as the rear wall of the stove where it mounts.i installed new gasket and reinstalled the pot.i decided since i had access to the back of the stove to remove the auger and installed the crossover tube.fired stove up today and bingo.no flames outside the pot and only smoke on start up.i believe you were having your crossover tube done today so hope things will improve once thats done.Peace,Corkman

Click to expand...

Thanks corkman I just posted a detailed account of what happened

tonyd said:

I also went to the 3/4 rope. When you close the door on the newer stoves, they close with resistance with the factory rope. When you use 1/2 " the door closes to easy. I think it seals much tighter with the 3/4.

Click to expand...

Hi tonyd
Yes I do like 3/4 for the door Thanks for pointing that out ! In this post I was referring to placing it behind the flame guide to keep it from moving the flames from going outside the burn pot which was my original problem on this thread

3650 said:

Well today something odd happened. As i have said the accentra is just my back up, but I've been burning it this shoulder season because I dont need the work horse for that. The secondary burn was happily flaming under and around the burnpot when I heard a.loud boom and the glass rattled in the stove door. I reckon those gases must have built up and ignited. This is the first time I've witnessed this since owning the stove. I dont think ill be leaving this burning unattended from now on.

Click to expand...

Hi 3650
Oh no
That was 1 of the things I was concerned about happening
Sorry to hear it happened to you .
I would highly suggest placing the vertical rope behind each side of the flame guide...
It did stop the flames from going outside the burn pot and it will only cost you a few $$ and a few minutes ...
In your case ( using the stove as a secondary ) I do not think you would have to remove the flame guide too often so it would not be that much of a pain to place the rope gasket and leave it ...

I also saw the air crossover kit on line for $34 if you like to tinker yourself... I watched the tech do it and other than taking the auger and slide plate out it was not a difficult " do it yourself " job... Normally I would have done it but the docs placed me on blood thinners recently so I have to be extra careful not to scratch or cut myself... otherwise I would have definitely been able to do the air crossover myself ... like I said though you can still stop the flames without the cross over kit and just the rope gasket... I think the local hardware store charged $1.99 a foot for the 3/4" ... and it is working like a charm...
Good luck and until you try the rope gasket or something I totally agree I would not be burning it unattended...
Just a thought ... if you have creosote all around the burn pot and do not want to clean it
I would buy the flat braided rope gasket about 1" wide and tuck it in each side of the burn pot space ( where the creosote is and even lay a piece on the combustion intake cover ( the shelf under the pot )... this will act as insulation and not allow the creosote to catch on fire...
Don't totally block the air flow with a thicker gasket though... might be worth a try in your case !
I would be interested to know if you try the gasket and if it works for you... It is a relief to have a properly working Harman Accentra 2 and I am happy to report we are still getting a much hotter burn ...

ian105 said:

I've been following your thread since last year, I also had issues with secondary combustion occurring outside of the burn pot in the exact same fashion - whispy flames heading down towards the combustion blower from behind the pot/guide area. I tried a new flame guide last year to no avail. Made cleaning a huge headache with the crunchy creo buildup behind the flame guide and along side the burn pot.

Have not yet tried your gasket suggestion but will as soon as I fire it up for this year. Last year I ran 24/7 this year will just be evenings/weekends with propane being cheaper then pellets for now. Ill post back with the results.

I am curious about your door gasket replacement choice, the original door gasket I believe is a 3/8 (.375) size. Going to 3/4 sounds like a huge jump. I would think 1/2 would lead to a very tight fit, if the 3/8 wasn't tight enough. I need to replace my door gasket as its getting crunchy at the bottom of the door. Looking for thoughts if I should just replace with 3/8, or maybe jump to 1/2.

Click to expand...

Hi ian105

You are correct the original gasket is 3/8".

My tech installed 1/2 "it is working fine so I am not going to change to 3/4 now.
Once it crushed down there is not as tight as a fit as in the beginning so it is up to you what you want to go with.
I personally like a tight door seal and will try the 3/4" like tonyd suggested when this needs to be changed.
Have a great evening and I wish you luck with your attempt at getting the flames behind the burn pot to stop...
We have been burning for a month now and no flames with this set up this year...
I am a happy camper... that creosote was horrible to clean not missing that ;-)