Harman P61-A burns low flame

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Honda

Member
Hearth Supporter
Nov 28, 2009
74
New Brunswick, Canada
I have been using a Harman P61-A for the past 3 winters, going on the fourth. The first winter, the stove worked awesome, loved it. The second winter I started having problems, and have wrestled with it ever since. The problem I seem to be having is that I can not get a consistent burn rate on stove temp. When the stove is working great, I can run it on stove temp, fan low-med, temp set around 75. It will burn a med to high size flame consistently and give a consistent heat output. However, I have not been able to achieve this since the first winter. The problem is that the flame burns low, so much that I have replaced two burn pot covers because they are warping form the low burning flame. I have consulted with my dealer, and he has made several visits, replacing ESP probes, motherboards, adjusting draft setting. Have done regular thourough cleaning. The only thing that has seemed to make a difference is when I cleaned the square exhaust port behind the ash box. There was a bit of ash buildup, and my theory was that this was holding heat and making the exhaust port where the probe is hotter than it should be. However, this only seemed to fix the probelm for a couple of weeks or around 10 bags of quality pellets. Something else I have noticed is that the stove seems to surge, it will feed pellets in so the flame is burning high in the pot, like I feel it should be, then it will slow down so the flame is coming pretty much form the feed tube, and then will repeat the cycle. The stove is just not working properly and efficently like it was the first winter. I feel I have exhausted all my efforts with the dealer. I have learned more tips and tricks on here than anywhere else.

Any help would be much appreciated, especially with the cold coming!
 
I'm sure this isn't your problem, and I'm embarrassed to admit this, but my stove was acting funky and it turned out I hadn't put the cover to the feed motor back on properly. It would start out burning really nice, then would go into low flame. Is your stove feeding pellets properly? Mine would start out feeding pellets fine, then when the flame started, it would stop feeding pellets for like 10 minutes. I'm assuming your stove does this in room temp mode as well? Like I said, I'm sure that's not your problem, but it sounded similiar enough to what mine was doing so I thought I'd throw it out there.
 
When you clean the stove have you made sure to clean the feeder box? If you have a lot of sawdust built up in there it can restrict the feeding of pellets. If you've ever removed the slide plate from the feeder box it is also possible that it is in upside down. The slide plate has a ridge on one side that should face upward. If the ridge is facing downward it can lead to too few pellets being fed.
 
the stove only acts up in stove temp mode, runs fine in room temp, will fill the firebox with flame and throw a tonne of heat. The only problem with this is the type of house I have. It is large and open, with high ceilings and a loft. I found that when stove temp mode works properly, I can heat the place evenly and burn the least amount of pellets.

Something that I did just notice a couple of days ago as I was troubleshooting is that when the fan is on high, stove temp mode, and I unhook my outside air, it will burn a good strong flame. But this seems to have no effect when fan speed is on low. In either case, fresh air hooked up or unhooked, the stove still surges. It gets a great flame going to where it should be, throws good heat, and then it backs off on the pellets until the flame drops way back in the pot, then it repeats. The reason I unhooked the fresh air is because I have a different setup, double walled pipe, where the fresh air is comes in by the exhaust pipe, and warms up as it comes through. I thought this may be causing some problem whereas it is only around the freezing temp here at this time. However, this is the same setup I had the first winter, and the stove worked great then.

I am going to take the ash box out and check the square exhaust tube again, clean it, and hope that will fix the problem again, even though I have only burned 30 bags of pellets since my dealer cleaned it this fall.
 
FIRST....I would sit in front of the stove and start timing the auger cycle.
If you're burnpot got warped I would think that something seriously wrong went on with the stove and could have warped somthing else.
You may have something like a intermittent vacuum switch...

when the stove gets hot
the case expands and exposes a leak (a crack)
opens vac switch
stops auger
stove cools
closes vac switch
starts auger
rinse and repeat :-/
 
could have a clogged auger sounds like it is not getting enough fuel. i have rebuilt 2 feeders on harmans this season for this same symptom
 
RETIRED GVA, it was the burn pot cover that warped, from burning such a low flame for alot of the time the past couple of winters. The stove runs like it should for the first half hour or so, and then once it is fully up to temp is when the surging starts and continues. It feeds great and the flames and heat go as they should, and then it will slow the feed gradually until the flames are coming from the mouth of the feed tube, as if in shut down, and then it will gradually fill the pot again and repeats. In room temp mode it works awesome, it makes me realize how crappy it is working in stove temp mode. As for the timing of the feed, I have not actually written down the times and cycles, but i know hen it is slacking off on the feed the motor only runs for a few seconds at a time, as if in shutdown, until the point when it decides it is going to fil the pot again, and runs for a longer time and more frequently.

I have never heard of the vacuum switch, is this something that has had problems before.

I think the auger is fine, it gets lots of fuel on startup and until the stove is up to temp, and runs fine in room temp mode.

I just did a thoruogh cleaning again yesterday, it was a little dirty, but nothing serious, and I did not notice any change in the way it is acting. I called my dealer, he is going to come and do some more troubleshooting, hopefully we can find the problem, otherwise I am going to have to look into trading in on a new stove.
 
I have the P61a, and I have to ask why would a low flame warp the cast iron burn pot cover. Lately with the warmer weather I've been burning a low flame for long periods of time, but why would this warp that cover? Are you talking about the flame guide that sits on the burn pot or something else? Also, shouldn't this stove be able to handle being used on low flame for long periods of time?
 
Harmanator- whats your feed adjuster set to?
 
Feed rate is 3.5. I am talking about the flame guide, I guess I referred to it as burn pot cover. Yes, it is cast iron, and it did warp so that it did not seat properly and the flame came up behind the logset alot of the time. My dealer told me it had warped probably due to the low flame. I realize that in the warmer temp it does not alwas burn full capacity. As well, I have turned the temp setting up to max and it still acts the same way, surges, full burn pot, empty burn pot. I just want to find out how to get it to burn a consistent full flame and throw consistent heat in stove temp mode. It does not work nearly the same as when it was new and it is driving me nuts. I was so happy withe the heat my first season. The first year I had the stove I ran stove temp mode, feed rate 3- 3.5, and temp setting 75 and it was all that I needed, and would bring the whole house up to temp in a couple of hours(large open concept). the past couple of winters I have had the temp setting on max and feed rate to 4- 4.5, and sometimes will not bring the house up to temp at all and even on these warmer days has a hard time getting the place warmed up. Something else, I get the whoofing and flutter flame that I have seen in other posts on here. Also notice the fluttering stop when the hopper lid is open. The lid seal looks ok. I do get a fair amout of dirt on the glass in the shape of the airwash on each side of the glass.
 
I have noticed on my P43 which has the same controls as yours that I need to keep the feed rate on 4 and stove temp on 4 to keep an even medium fire, when its not that cold i turn the stove temp dial to 3 or even 2.5 and the flame burns lower in the pot and a small fire, active but not like it would be when on 4....seems normal to me....I think your stove may be plugged as they say
 
hmmm, I don't know really, thanks for the info everyone. I will mention the feed being plugged when my dealer is here, but I'm pretty sure everything is clear there, I can't see in the feed tube, but the slide plate is clean.

When I talk about low flame, I mean low as in the same as shut down mode, when the flame comes from deep in the pot, the end of the feeder tube, with very very few pellets in the pot. I don't seem to remember this to be normal on stove temp mode, especially with the surging from full burn pot to empty.
 
sounds more like a board issue does not sound like a mechanical issue
 
see if you can get your dealer to hook up the DDM to the control board and see what temps the ESP probe is seeing. I dont think its all that unusual to go through a flame guide, but the surging in stove temp is odd for sure. If the ESP thinks the stove is at a particular heat level it has a temp "window" that it tries to operate in, and it will alter its feeding habits to maintain itself in that window.
 
another simple thing to check (although it does not explain away all your issues, but worth a shot) is the flapper on the air inlet... during long months of sitting cold, or if you have an outage and smoke backs up, it can get sticky, thus it does not allow a sufficient amount of air into the pot for a good burn..
 
summit said:
another simple thing to check (although it does not explain away all your issues, but worth a shot) is the flapper on the air inlet... during long months of sitting cold, or if you have an outage and smoke backs up, it can get sticky, thus it does not allow a sufficient amount of air into the pot for a good burn..
summitt, is this flapper suppose to move far if you push it in?....i gave the flapper a quick check when i hooked up my OAK and although it was free didn't move very far
 
Delta-T said:
see if you can get your dealer to hook up the DDM to the control board and see what temps the ESP probe is seeing. I dont think its all that unusual to go through a flame guide, but the surging in stove temp is odd for sure. If the ESP thinks the stove is at a particular heat level it has a temp "window" that it tries to operate in, and it will alter its feeding habits to maintain itself in that window.
I agree with Delta
This will tell you if the board or the ESP is funky.
Have them do a draft check while they are there to see if you're exhaust is funky.
Since it's running fine in room temp that narrows it to the 3 things above
 
thanks folks. I do not claim to be an expert by any means, but I have educated myself alot through talking with my dealer and this forum, over the past three winters on the ins and outs and mechanics of these great stoves. When I spoke with my dealer he said he is coming to do the temp test, and I will make sure to have him check draft as well, I'm pretty sure it was not done after he switched the board this fall. That was done due to my dist fan dial going bad. So, I have a brand new motherboard, the ESP is a few years old, and I really hope that is the culprit.

Does anyone know what the temp range the stove will try to maintain is for say a temp setting on the stove of 75F. It would be nice to know for assurance of his diagnosis.

Would also be interested in any opinions anyone had on Ambiance hardwood pellets made by Valfei. I have been burning them so far this year, and have a couple tonne in the garage, seem to be just OK so far. Haven't really had cold enough weather to be able to make an opinion on the heat output. The ash output seems to be more than the LG's or Shaws. I like to mix in some corn for the lower heat output pellets, it really seems to beef up the heat output, and also seems to keep the burnpot claener. I could be wrong, but when I mix some corn in with a good pellet, seems to keep the ask accumulation lower, and I don't seem to experience big clinker buildup like I have heard talk of before.

As far as feed problems on my stove, I really think it is ok. With the only exception being carbon buildup inside the tube, everywhere else is regularly checked and cleaned.
 
I burned the ambiance the 1st year burning..........
I would never get them again, They are a step above the box store pellets though.
 
HEMI said:
summit said:
another simple thing to check (although it does not explain away all your issues, but worth a shot) is the flapper on the air inlet... during long months of sitting cold, or if you have an outage and smoke backs up, it can get sticky, thus it does not allow a sufficient amount of air into the pot for a good burn..
summitt, is this flapper suppose to move far if you push it in?....i gave the flapper a quick check when i hooked up my OAK and although it was free didn't move very far

It flaps maybe 1/2 - 2/3 way open during normal operation.. if its swinging free, sometimes you hear the "tink tink" kinda noise outta it when it starts up and fire gets established.
 
I think from now on I will stick with the Shaw eastern Embers or the LG's. I have burned several tonnes of each over the past three winters and had no issues with either and they produce low ash and throw good heat. As I mentioned above, on the really cold snaps, a little corn mixed in at a ratio of 40/60 or less works great. I also like to hold off on the corn to a point where the stove is running consistently so there is no issues with startup with the corn mixed in.

I have realized a side effect of this surging problem I am having. Each time the feed slows to a point the flame burns low in the pot or from the feed tube, and restarts the feeding process to build the flame, there is an excessive amount of fly ash. As the pot starts to fill again, the pellets feeding in stir up the ash and embers, creating a large amount of fly ash. I can only imagine that this will increase the need for cleaning. I know when the stove was working properly, a yearly cleaning of the exhaust pipe is all that was needed, and each time I emptied the ashes, I would clean the inside of the stove, heat exchanger and ESP probe. I have been cleaning more frequently recently, and I expect this excessive amount of fly ash is the culprit.

My dealer has not been able to make it down yet to do a another diagnosis. I will post an update as soon as he does. Fingers crossed that the ESP probe is the problem.
 
For those of you that kindly following this thread, I think I may be on to what is causing the problems with my stove. While waiting for my dealer to come do a diagnostics test, I have been fiddling around a bit with the low draft voltage dial. I knew that it was not set after getting the new motherboard this fall. It was set at the vertical position, straight up and down. I tried it 1/4 turn counterclockwise, no difference. So I tried a 1/4 past up and down in the clockwise direction, say the 2 o'clock position, and have noticed a difference. It seems to be burning higher in the burnpot, and quite consistently. It will still surge a bit, but on the low end of the surge it is not burning from the feed tube. Maybe with a little tweaking and a draft meter this will get the stove back to working how it should. I feel that it is close now, but I will have to watch it for a day or two more to make sure. I still get the flicker flame and whoofing.

Does anyone have any input on this? Does anyone have any background on the ESP probes, when they are bad would it cause what I am experiencing, or does it make the stove act really crazy?
 
Harmanator said:
For those of you that kindly following this thread, I think I may be on to what is causing the problems with my stove. While waiting for my dealer to come do a diagnostics test, I have been fiddling around a bit with the low draft voltage dial. I knew that it was not set after getting the new motherboard this fall. It was set at the vertical position, straight up and down. I tried it 1/4 turn counterclockwise, no difference. So I tried a 1/4 past up and down in the clockwise direction, say the 2 o'clock position, and have noticed a difference. It seems to be burning higher in the burnpot, and quite consistently. It will still surge a bit, but on the low end of the surge it is not burning from the feed tube. Maybe with a little tweaking and a draft meter this will get the stove back to working how it should. I feel that it is close now, but I will have to watch it for a day or two more to make sure. I still get the flicker flame and whoofing.

Does anyone have any input on this? Does anyone have any background on the ESP probes, when they are bad would it cause what I am experiencing, or does it make the stove act really crazy?

How does the draft probe work on these stoves? I have a P61A and was just looking at my control panel. I assume the draft setting is the dial that actually looks a little like a screw? Mine is set almost in the 10 O'clock position which seemed strange to me. Can somebody explain what this does for me?

The ESP probe, is that the same as the room sensing probe? I have seen it called both on different occasions. My room sensing probe went last winter and when I turned it to room temp it just plain wouldn't work (the stove I mean), it basically went into shutdown.
 
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