Why does my stove sound like a subwoofer? Low frequency vibes... Help!

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Totally agree, harman should respond here. I know that I like my stove, but the woofing noise would be enough to make me not recommend it to someone else. If I had to do it over again, I'd probably buy the quad classic bay. I know, harman and quad are both owned by HHT.

Seems like some decent engineers at Harman could come up with a solution, a retrofit fan, or some type of modification. Let's see if they respond, if not maybe we start a concerted email or letter writing effort to get their response.
 
I have a simple install as well. about 6 feet vert, 90 deg, out through the wall 3 feet. I have OAK. My low voltage draft adj is set as low as it will go by my dealer when he did the install. What makes me wonder is that my stove did not whoof the first year I had it.

Sometime during the second year I experienced my first ignition "explosion" where it does not light immediately, builds up a crazy amount of smoke, and then ignites with a bit of a boom and pressure, resulting in a small amount of smoke blowing by the door gasket. It has since happened a couple of times. I now watch it, and if it is slow going I crack the door handle a whisker and that keeps it from exploding on ignition. I always wondered if this compromised any gaskets. And the whoofing seemed to appear sometime after this first instance. could be purely coincidence.

I also get a small squeal or whistle right when ignition starts, only lasts about 10 sec, just as the pellets are lighting. Will do hopper lid and see if that helps. I read on another thread that it was the air whistling as it went through the holes on burnpot. I know it did not do it new.
 
For what it's worth, both my old Quadra Fire and my new Harman Advance tend to light similar to your P61. I've always had a good bit of smoke in the stove before it ignites, I just assumed that most pellet stoves were like that. And my old Quadra Fire Santa Fe whistled when it first started up, it was caused by air rushing through the little holes in the burnpot. The Harman doesn't whistle - at least not yet, lol.

On mine, if I crack the door or the ash hopper door just a tiny bit, that relieves a bunch of pressure and I get little or no woofing. I found an old .pdf maintenance manual for Avalon stoves from 1999, and that particular stove actually had a plate in the intake air tube that could be moved to partially block the incoming flow of air. No such way to do that on the Harman stoves.
 
I notice that I will get woofing on my Accentra insert, when I open the hopper lid to add pellets when it is (or near) empty. I never get it during normal operation. That would seem to mimic the person who gets the problem when their hopper is less than half full. I would agree that it is a draft issue, and probably a leak at or around the hopper.
 
bcb1 said:
For what it's worth, both my old Quadra Fire and my new Harman Advance tend to light similar to your P61. I've always had a good bit of smoke in the stove before it ignites, I just assumed that most pellet stoves were like that. And my old Quadra Fire Santa Fe whistled when it first started up, it was caused by air rushing through the little holes in the burnpot. The Harman doesn't whistle - at least not yet, lol.

On mine, if I crack the door or the ash hopper door just a tiny bit, that relieves a bunch of pressure and I get little or no woofing. I found an old .pdf maintenance manual for Avalon stoves from 1999, and that particular stove actually had a plate in the intake air tube that could be moved to partially block the incoming flow of air. No such way to do that on the Harman stoves.


I do not get the big smoke every light, just sometimes, especially if I do not clean the partially burnt stuff and ash out before lighting.
 
I called the dealer today to tell them about another problem I am having. While on the phone with them I asked if the burnpot was in yet, but it's not. I wanted to know more about what Harman had to say about this issue. Harman says they are aware of the problem and are redesigning the burnpot. I will be getting a prototype of this new burnpot. I don't know if I want to be a guinea pig, but what the heck, if it works, great!

Harman also said that the only issue with the woofing/fluttering is that it is annoying. It cannot hurt the stove, etc. So besides being annoying no damage can be done, so that's good. Now off to post about this new issue, my tech hasn't had this one happen yet, either.
 
PJPellet said:
I called the dealer today to tell them about another problem I am having. While on the phone with them I asked if the burnpot was in yet, but it's not. I wanted to know more about what Harman had to say about this issue. Harman says they are aware of the problem and are redesigning the burnpot. I will be getting a prototype of this new burnpot. I don't know if I want to be a guinea pig, but what the heck, if it works, great!

Harman also said that the only issue with the woofing/fluttering is that it is annoying. It cannot hurt the stove, etc. So besides being annoying no damage can be done, so that's good. Now off to post about this new issue, my tech hasn't had this one happen yet, either.

Because the woofing/fluttering is not causing any damage will the burnpot upgrade (if it works) be an optional service that the stove owners will need to foot the bill for?
 
PJPellet said:
I called the dealer today to tell them about another problem I am having. While on the phone with them I asked if the burnpot was in yet, but it's not. I wanted to know more about what Harman had to say about this issue. Harman says they are aware of the problem and are redesigning the burnpot. I will be getting a prototype of this new burnpot. I don't know if I want to be a guinea pig, but what the heck, if it works, great!

Harman also said that the only issue with the woofing/fluttering is that it is annoying. It cannot hurt the stove, etc. So besides being annoying no damage can be done, so that's good. Now off to post about this new issue, my tech hasn't had this one happen yet, either.

Awesome, super. Thank god the stove will be fine. Now, what about my nerves? Sheesh.

Still cant see how this is a pot issue, but smoke if you got it. :)
 
All right, the big day is tomorrow! I couldn't wait to see the new burnpot so I drove to my dealer today to look at it. Here are some details:
1. Bigger, deeper burnpot.
2. Ignitor location is different.
3. Ignitor is the same but ignitor cradle is different.
4. More airflow through burnpot.
5. Flame guide is the same.
6. Harman still in the design phase of this burnpot, so I will be getting a hand-made prototype. (hope that's a good thing)

Going to start another thread with this same information and will update as soon as I can when the new burnpot prototype is installed.
 
Just ever so slightly opened the ash pan drawer (lifted the lever and slowly cracked the door open so there was BARELY a crack in it and noticed the booming sound. Maybe there is a slight leak around a gasket somewhere? I do notice that when the stove is starting there is a quiet whistle. Haven't been able to pinpoint where it is coming from but I wonder if it is where the first streak appears on my glass.......

My stove does the same thing. Not all the time, it comes in spurts flame flutters and low rumble starts. But as soon as auger starts the flame becomes steady and rumble starts. Did u fix your problem?
 
My stove does the same thing. Not all the time, it comes in spurts flame flutters and low rumble starts. But as soon as auger starts the flame becomes steady and rumble starts. Did u fix your problem?
I haven't noticed the rumble for quite a while. Still a mystery to all of us I think.
 
my stove was doing the same thing. i called my dealer and he asked me to bring my fines cover in. he took a look at it and noticed that there was no indent around the top of the pad which leads him to beleive that its not all the way sealed and air is leaking. he ordered me a new cover. hopefully that is the problem. he said that a few other people have had the same problem in our area.
 
my stove was doing the same thing. i called my dealer and he asked me to bring my fines cover in. he took a look at it and noticed that there was no indent around the top of the pad which leads him to beleive that its not all the way sealed and air is leaking. he ordered me a new cover. hopefully that is the problem. he said that a few other people have had the same problem in our area.

Did a new fines box cover solve the problem?
 
It helped a little, but the main problem was my latch on the hopper lid was loose. I tightened it up the nut and it's sealed nice. Doesn't do it anymore.
 
I just produced the harmonic in my stove on a hard manual start. I would have to agree that it's draft related. I used to induce the ram jet effect on fuel oil stoves. Check the history on the V1 German rocket. Lennox made a very high effiency furnace based on the principal and was a noisy one.
 
My stove was brand new installed in August and I have noticed this vibration as well. For me, it sounded like a tractor trailer coming from a distance, and then realized it was the stove. I will have to note the flame height correlation mentioned many posts ago.
 
It helped a little, but the main problem was my latch on the hopper lid was loose. I tightened it up the nut and it's sealed nice. Doesn't do it anymore.
My hopper lid latch seems pretty tight. I get it on occasion. Not a regular occurrence.
 
Mine hasn't done it since I tightened that latch. I dont even know how it became loose.
 
They only fill the gear box with enough to cover the gears, so maybe a 20% fill. I will fill/pack to 80% and see how it goes.
This is a little off topic. That is not how grease works. Grease is a suspension of oil in soap. The oil weeps out of the suspension to wet the surface of the moving parts. If the parts are continually in contact with the grease it puts a substantial load on the motor. The higher the speed of operation the worse over-packing is for the motor. Even though the output shaft is moving slowly the motor shaft is still moving at a high speed. The motor will run hotter as a result of over-packing the gear box and you are not improving the life of the gearbox. While over-packing will dampen the sounds that a gearbox makes, it doesn't make it work any better.​
 
My Mt Vernon was doing the same 10Hz flutter this evening. I noticed that the flame was like a blow torch. Having cleaned the stove this afternoon, I assumed it was something that I had done. I found that the ash pan wasn't pushed in all the way. I pushed it in and the flame returned to normal, the sound stopped.
I really think that you are hearing a resonance in the system driven by an very hard draft. There are lots of things that can dampen the resonance, but the hard draft is wasting fuel anyway, so why not fix the driver rather than the driven.
 
I just purchased a P35I two weeks ago and had it installed and it has an annoying rumbling sound when the flame is high and the stove is hot. I checked the hopper, door and glass seals, they all look good. I talked to our installer about this issue, but he seems to be at a loss on what to do. Based on some of the threads I've read it seems it might be a known issue with some of the Harman inserts. The stove performs great with the exception of the annoying rumbling sound. If anyone should happen to figure out what the root cause is I would greatly appreciate that info. By the way, the stove has the curved burn pot cover. Thanks in advance for any info
 
I just purchased a P35I two weeks ago and had it installed and it has an annoying rumbling sound when the flame is high and the stove is hot. I checked the hopper, door and glass seals, they all look good. I talked to our installer about this issue, but he seems to be at a loss on what to do. Based on some of the threads I've read it seems it might be a known issue with some of the Harman inserts. The stove performs great with the exception of the annoying rumbling sound. If anyone should happen to figure out what the root cause is I would greatly appreciate that info. By the way, the stove has the curved burn pot cover. Thanks in advance for any info
What type of pellets are you using? Mine only does it on Green Teams, I get a light flutter with my LeCretes and McFeeters but no woofing.
 
What type of pellets are you using? Mine only does it on Green Teams, I get a light flutter with my LeCretes and McFeeters but no woofing.
I am currently burning Pro Pellet, this is what the installer recommended. 'm not sure just how many brands are available in my area, Ann Arbor, Mi., but I will take a look to see what's available in the area. Thanks for your input!
 
I did not read all the posts in this thread so I may be repeating what others have said.. My guess is since all of those stoves are most likely very much the same and you said it does it with the OAK removed ...my bet (higher then a guess) is its the vent pipe. change something there and bet it goes away. It sounds like a resonance and they can be easy to deal with when you find the "culprit".....or you could put a beat to it and make music with your stove...
 
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