Harman 52i insert. It seems not enough combustion air is causing the fire to quickly quit and stop the stove.

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.

wallyspam

New Member
Mar 14, 2021
4
New York
So. I gave my stove a good first of the year cleaning last week. Bear with me on being complete here as I always read people asking for help and not providing any info.


What I cleaned:
I didn't pull it out to clean but I cleaned all the inside. Including the burn pot holes, the area inside the burn pot with the igniter inside there deep and thorough. Behind the removable metal plates including behind them along the walls. I did not take off the combustion door and clean the fan BUT I did thoroughly clean all the underneath, where the removable long metal plate is with the set screw on the right.​
What I didn't clean this time:
So I didn't clean the combustion fan itself, it wasn't touched. (More on this later) I cleaned around the door but didn't open it. And like I said I did not pull it out to clean behind, I need a helper for that and they weren't around.​

After all this I can't remember if the next burn, or within a day, this issue started but the prior month of daily use it was not having this issue.

The issue:
The stove is turned on, it feeds normally, it ignites, but when this started it would ignite fine and then the flame would whimper out within 30 min. Last night after doing some tests (more on that later) it ignites some pellets and then it doesn't even produce a flame, just embers. And this flame was like 10-20% of a normal raging fire. It was a weak fire and it was odd because instead of the fire reaching way up the wall inside it barely reached the medallion above the burn pot. Something in the sensors must eventually tell it to quit as it doesn't seem to get going enough for it to continue.​
To be complete but keep this from getting too long the issue I am now convinced it is related to airflow, the fire is not getting enough in some way and it just quits eventually. So last night my Uncle came over, and we checked the 3 fans. 1 combustion and 2 distribution fans. We cleaned them all out. We put a wire brush up 15 feet of the chimney and cleaned that, he didn't think what fell out was too dirty, nothing hard or blocking.​
I cleaned the combustion fan well, including the 12inch tube that goes up to the chimney flue. Put the combustion fan cover back on right. We were suspecting it may be this fan. After we pulled it out this fan motor was very hot to the touch but the fan spins extremely well after spinning it manually. We disconnected it and did the old wire trick to the power outlet to feed it 110v. I felt the air pressure coming out the tube in the back and it has to be good. It was a lot of air flowing out. Still if we had to guess this lack of air movement is preventing the fire from starting fully. The distribution fan does come on and blow full speed as normal but its not long after they kick on that the fire is whimpering out so the air is barely warm. I have seen it give a 5 code blink and a 6 code blink. I haven't checked everytime but we do get codes. Also I forgot to mention the gasket on door seems ok but I have one being delivered today.​
I got a service call from the local dealer on Saturday but wondering if this post may give me another idea to check first. Sorry to be long but trying to be complete.​
 
Last edited:

DAKSY

Full Time RVer
Staff member
Dec 2, 2008
9,546
Wherever we're parked
You may need to clean the fines box, & I believe you're gonna hafta pull the insert to do that.
I had an issue with my P43 that is similar to what your insert is doing & the fines box was the culprit.
 
  • Like
Reactions: Mt Bob

rickwai

Minister of Fire
Nov 1, 2011
1,347
ohio
Empty your hopper and be sure there is not a obstruction in the bottom. I have seen a piece of cardboard partly blocking the slide plate cause this same issue. You can reach down in around the corner once all pellets are vacced out. Also how long are the pellets? I have seen long pellets cause a log jam and reduce flow and cause weird issues
 

wallyspam

New Member
Mar 14, 2021
4
New York
You may need to clean the fines box, & I believe you're gonna hafta pull the insert to do that.
I had an issue with my P43 that is similar to what your insert is doing & the fines box was the culprit.
I forgot to mention that when I did pull it out to look at the fans I got in and cleaned the fines. Worst thing is since it isn't burning much I can't work through the pellets in the hopper. I may get out the shop vac and empty it to do the fines clean again. Thanks.
 

wallyspam

New Member
Mar 14, 2021
4
New York
Empty your hopper and be sure there is not a obstruction in the bottom. I have seen a piece of cardboard partly blocking the slide plate cause this same issue. You can reach down in around the corner once all pellets are vacced out. Also how long are the pellets? I have seen long pellets cause a log jam and reduce flow and cause weird issues
Ok, I will do this. The auger seems to work fine. Last year my 2 year old somehow got a bogle dice in there and completely stopped the auger. We have been very careful this year and it seems to work ok so didn't assume it was that. I will do the cleaning of pellets first and see whats going on in there. Thanks.
 

Montecarlossfan

Burning Hunk
Jan 1, 2019
158
Connecticut
If you saw a 5 and 6 blink...5 blink meaning it doesn't sense it has started and 6 meaning a bad values from the esp. I would clean the esp probe, try again and if that doesn't work, purchase a new one(preferably oem). It seems like its igniting, but never sees that it has started so it ceases to feed.
 

DAKSY

Full Time RVer
Staff member
Dec 2, 2008
9,546
Wherever we're parked
I forgot to mention that when I did pull it out to look at the fans I got in and cleaned the fines. Worst thing is since it isn't burning much I can't work through the pellets in the hopper. I may get out the shop vac and empty it to do the fines clean again. Thanks.
You don't need to clear the hopper to access the fines box. It can be cleaned from behind the unit.
If you DO get in there & clean it, make sure the cover for the fines box is seated correctly.
 
  • Like
Reactions: rickwai

rickwai

Minister of Fire
Nov 1, 2011
1,347
ohio
If you saw a 5 and 6 blink...5 blink meaning it doesn't sense it has started and 6 meaning a bad values from the esp. I would clean the esp probe, try again and if that doesn't work, purchase a new one(preferably oem). It seems like its igniting, but never sees that it has started so it ceases to feed.
6 is incomplete combustion. Which can be many things including this scenario. Not coming up to temp as quick as the board thinks it should. So it shuts it down thinking there is a potential problem
 
  • Like
Reactions: Mt Bob

tiger

Feeling the Heat
Feb 3, 2014
438
Seabrook, MD (DC suburbs)
You don't need to clear the hopper to access the fines box. It can be cleaned from behind the unit.
Aye, but added weight of pellets makes the whole unit that much heavier to pull out. Nobody ever said I had to do it, but each time I laboriously empty the hopper, using a small scoop (yeah, planning ahead to to a cleaning at the end of a bag's burn is smarter still), plus the door comes off, etc. YMMV.
 
  • Like
Reactions: Mt Bob