Harman XXV - auger screeching - how do I remove it?

[GuyInNH]

Hi, I've had a Harman XXV for about 6 weeks now. I'm not new to pellet stoves, had 2 before at previous houses. But, this is my first problem like this. Two days ago, the auger started making a horrid high-pitched screeching sound each time it turns. I've thoroughly cleaned the stove, and I see no sign of the auger scraping the sides of the tube, at least in front (not 100% sure about in back). The noise is loudest out the back of the stove, and it goes away while I am pressing my hand against the back of the auger motor, only to start immediately again once I release my hand. It is quite unbearable, makes my ears hurt within a few minutes.

The local pellet stove store is booked up for appointments, and this was intended to be my primary source of heat. Its not some novelty item that I can merrily wait around for over a week for someone to show up. I've been trying to fix the noise, and also have been making several trips to/from the pellet stove shop to discuss this with them.

I'm thinking that either the auger isn't aligned properly in the tube, or there's a pellet wedged against the back end of the auger that is scraping. (Although if that's the case, wouldn't friction wear out the wedged pellet and sound go away? It is getting louder.) I opened up the panel that lets me clean out the fines that collect back there, and vacuumed them out. From what I can see, it looks fine in there but my visibility is terrible so I can't be sure.

So, I've been trying to remove the motor and then the auger. I have a corner installation. I haven't been able to get a tool properly onto the set screw for the auger motor well enough that I can apply sufficient force to budge it. There's hardly any room at all the work back there. I've tried socket extensions, including a flexible one. I've tried the auger in different positions to move the set screw to different places to try to reach from other directions. I'm stumped! I have no idea how to get this thing off. What do people do?

Assuming I can get that off, then how would I reach the two bolts that hold on the flange? I can see them, barely, but that's about it. They look even more inaccessible than the set screw. What would people recommend?

 

[GuyInNH]

One more thing, here's a video that perfectly demonstrates what the noise sounds like. This is not my video, just something I found on youtube. The sound is identical in every way (and he hasn't solved his yet either):

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[SmokeyTheBear]

Scrape the carbon build up off the stove at the end of the auger.

Increase your feed to the recommended feed setting if it isn't already there.

What year is the stove?

 

[GuyInNH]

It's clean, that isn't the problem. The burn pot and the coal-like carbon deposits are thoroughly scraped off of it, not merely swept off like people often make the mistake of doing. The tube (the part I can see from the front) had nothing in it other than discoloring. I understand everyone likes to say clean it since lack of proper cleaning is a common mistake. But, that isn't what is going on here.

Feed setting is at 4; that does not matter, it screeches at any setting. The year of the stove is October (this year). I have only burned about 30 bags of pellets so far.

Pressing on the motor stops the noise; any thoughts on what that might indicate? I don't see the auger shifting position at all when I do this, but the motor itself wobbles a little bit, maybe 1/8". I have no idea if this is normal though for it to move a bit.

 

[gfreek]

My guess having experience similar noise on my Harman that was only months old, warranty replacement of the auger motor.... Service tech should have one on truck...

 

[SmokeyTheBear]

It's clean, that isn't the problem. The burn pot and the coal-like carbon deposits are thoroughly scraped off of it, not merely swept off like people often make the mistake of doing. The tube (the part I can see from the front) had nothing in it other than discoloring. I understand everyone likes to say clean it since lack of proper cleaning is a common mistake. But, that isn't what is going on here.

Feed setting is at 4; that does not matter, it screeches at any setting. The year of the stove is October (this year). I have only burned about 30 bags of pellets so far.

Pressing on the motor stops the noise; any thoughts on what that might indicate? I don't see the auger shifting position at all when I do this, but the motor itself wobbles a little bit, maybe 1/8". I have no idea if this is normal though for it to move a bit.

I'm just running the common causes of noises associated with the feed and I've seen pellets that can lay down a lot of deposits in a very short period of time.

Is the auger centered in its tube?

If it is centered then get a new auger motor otherwise you need to adjust it so it is or check to see if the auger is out of true.

Normally auger motors are free to move around (along their rotational axis) before stopping and your pressing the motor gives no clue as to in what manner you are pressing things.

 

[Don Myers]

I had the same occasional screeching last year when I was using a specific brand of pellets (Trebio). Only had half a ton to try out and I won't get again. I have used Green Team pellets the remainder of time with no screeching noises. Knock on wood!

 

[Chain]

Wow! I noticed the same exact problem when I got home from work last night. I've had my P-61A since this past April and this is my first heating season with it. My screeching, high pitched noise occurred whenever the auger turned and so I first suspected maybe the auger motor was not functioning properly or needed some lubrication. I quickly called my dealer and they immediately suggested that I clean the carbon build up right in front of the auger and inside the auger tube gently with a moist paper towel and flat headed screw driver. I did so and the noise occurred much less often. I tried again and the auger was now in a slightly different position and allowed me to get a spot I must have missed. It solved the problem for the remainder of the evening and still this morning when I left the house. Hopefully it'll still be fine when I get home today. But a lesson learned either way. That being that I have to make a better effort at really cleaning the burn pot right down to and slightly inside of the auger area itself. I stress gently of course. You may want to give the auger area another look for carbon buildup. Especially if the auger is in a different position. Good luck and let us know how you make out.

 

[Delta-T]

if the noise goes away when you touch the motor its probably not carbon. the metal "eye" shaped bracket that supports the bearing for the motor shaft might not be tightened up all the way. try tightening the 2 philips head screws that are right there facing you. I have seen this happen once before, was very long day of hunting for trouble, only to find 1 lose screw....motor prolly built on a friday afternoon, or monday morning.

 

[Hoot23]

Mine squealed like that, my dealer said to turn up the heat and let it run. It did it when it was about 3 months old. Hasn't done it since.

 

[TheMightyMoe]

I don't have a XXV but I made a little guide to removing the auger - my signature. In the XXV manual it looks very similar to the P series.

I had a very similar sound, after maybe 20-30 bags, pulled the auger, cleaned, tightened everything up, and the squeak went away.

Good luck!

 

[Chain]

My screeching noise hasn't returned so I'm guessing in my case it was indeed the carbon build up just inside the auger shaft. Did you try tightening the screws as Delta suggested, GuyinNH?

 

[GuyInNH]

My attempts to get the motor and auger out were hopeless... I can't figure out how you can get back there, especially when the stove is located in a corner. I suspect it is a little less painful to deal with this if you're against a side wall instead of a corner. Best would be out in the open, of course.

Good news though, I managed to get the guy to come over from the pellet stove store today. As I suspected, it was clean. The loud noise was coming from the auger; it has tiny burrs along the blades, plus Harman designs them so that the tolerances are too tight. If anything is even the slightest out of whack, that's enough for the auger to brush the inside of the tube back in there. Much to my surprise, he replaced it with an auger that had been modified at the shop -- they had cut down the diameter of the auger at their shop so that it has more clearance in the tube. (I bet they must see this problem a lot. I have no idea how many other stores out there do this... I was surprised that they'd do anything other than replace with an identical auger from the factory.)

I didn't mention this in my original post, but yesterday I noticed the motor made an odd buzzing sound too. This sound is only audible when the rear cover is off. I wasn't sure if it was normal or not. Pellet stove guy says its not normal. So, he replaced the motor too, and now that noise is gone.

So far, all looks well. Meanwhile, Harman should get a better handle on how their stoves work out in the real word and tweak their designs to be more robust.

 

[TheMightyMoe]

Glad you got it figured out!

 

[gfreek]

Glad you got it taken care of. Harman is a good brand, but at times like with anything, there are issues...

 

[Jefflitzy]

I Have had this happen - Loosened the auger motor bolt, pulled motor back at most a 1/16" let it do a couple of revolutions in test mode and tighten it back up.

 

[nhdblfan]

Going on my 5th "winta" with my XXV, I did have that auger out once (it is in a corner and a bit tight),it does come out just needed a flex ratchet to get the nut you can't see out if I recall.Every once and a while I get some nice out of it but it goes away.

 

[tjmuenc]

It's clean, that isn't the problem. The burn pot and the coal-like carbon deposits are thoroughly scraped off of it, not merely swept off like people often make the mistake of doing. The tube (the part I can see from the front) had nothing in it other than discoloring. I understand everyone likes to say clean it since lack of proper cleaning is a common mistake. But, that isn't what is going on here.

Feed setting is at 4; that does not matter, it screeches at any setting. The year of the stove is October (this year). I have only burned about 30 bags of pellets so far.

Pressing on the motor stops the noise; any thoughts on what that might indicate? I don't see the auger shifting position at all when I do this, but the motor itself wobbles a little bit, maybe 1/8". I have no idea if this is normal though for it to move a bit.

Did you solve the problem in your situation? Thanks