Harman XXV feed problems

[Corie]

A friend of my parents has an XXV, and is having feed problems. I'll do my best to describe it.

She said that sometimes during the night or during the day, the stove will stop feeding pellets. Usually all it takes to fix the problem is sticking your hand in the hopper and sloshing the pellets around a little bit. It's a problem because the stove will sometimes go out during the night and they'll wake up to a cold house.

It has happened with several different brands of pellets and when she contacted the dealer (who is an idiot in my opinoin, and by the opinion of many others) and he said its because she's not burning his brand of pellets. She said it occured with his brand, as well as the brand she is currently using.

Ultimately it sounds like a feed motor on its way out to me, but that's just a general guess as I am not super knowledgeable when it comes to pellet stoves.

Anyone care to share a similar situation, or something she can do?

 

[HarryBack]

well, I dont think its the feed motor if all you have to do to fix it is swish your hand around in the bin. It sounds more to me that your pellets are bridging off in the bin. This happens a couple of ways. If there are alot of really long pellets in the bin, they can interlock, forming a cavity and thusly not allowing the pellets to fall into the auger. Another wa y this happens is if your pellets have huge amounts of fines in them, either just a dirty brand, or they are making an attempt to burn pellets which have gotten wet and swelled, forming sawdust. The fines cause the pellets to hang up in the bin and not fall into the auger. I would take a good look at the pellets and see if that isnt the issue. Ive seen customers with huge hard clumps in there from the pellets getting wet, and that hangs the whole thing.

Another less likely but plausible scenario is the feed mechanism needs to be cleaned. If there are excessive fines, the arm that operates the slide plate will get stopped, causing the slide plate not to move, and no pellet delivery. In the back of the unit, behind the rear cover is a plate with a big bright wing nut on it. Undo the wingnut, remove the plate, and take a look inside...see anything? see a wall of sawdust packed tightly? vacuum it outta there.

Your foolish dealer who blames the issue on the fact hat they arent HIS pellets is a dope, although, if your pellets have alot of fines, he might be partly right. If there are alot of fines, try a few bags of another brand, from a different dealer....

Good luck!

 

[GVA]

A friend of my parents has an XXV, and is having feed problems. I'll do my best to describe it.

She said that sometimes during the night or during the day, the stove will stop feeding pellets. Usually all it takes to fix the problem is sticking your hand in the hopper and sloshing the pellets around a little bit. It's a problem because the stove will sometimes go out during the night and they'll wake up to a cold house.

It has happened with several different brands of pellets and when she contacted the dealer (who is an idiot in my opinoin, and by the opinion of many others) and he said its because she's not burning his brand of pellets. She said it occured with his brand, as well as the brand she is currently using.

Ultimately it sounds like a feed motor on its way out to me, but that's just a general guess as I am not super knowledgeable when it comes to pellet stoves.

Anyone care to share a similar situation, or something she can do?

1) what kind of pellets?
2) how are they stored?
3) What leads you to think the motor is on its way out?

I have had a bit of practice on the feed motors. If the motor is the culprit like it's on the way out, some thing I have noticed is it sounds like the little engine that could with a clunk and a pop noise or all of a sudden there will be a high pitched whining noise followed by a grinding noise when the auger is feeding. The whining is a spot on one of the gears is actually stripped and the engages good teeth on the secondary gear.
The best test on a gearbox I have found (in my industry) and it should work with everyone else is if you can turn the output shaft on a gear box by hand and the input shaft turns (in your case the fan that cools gearbox) than the gearbox is junk. This works on anything over a 10 to 1 ratio, less than this and the output shaft will usually turn.
If it's a Gleason Avery like on mine it's 800 to 1 ratio (per GA) and this will you will never be able to turn by hand.
One thing to keep in mind:
If is not the pellets bridging in the hopper it could be a leak in the stove, the auger will not feed if there is no pressure differential. If you open the front door for example the auger will stop..... The Harmans will only run the feed motor a certain number of times before you get the 6 blink status are they getting this?
The 6 blink status is caused by many things the only time i've had it is if I let the stove run out of pellets at night or the motor has failed completly.
If the stove shuts itself down and they turn the stove off and back on without swishing the pellets around in the hopper and it starts back up your looking at another problem not bridging post back with more info and trust us we can narrow it down...

 

[Corie]

GVA and Harry,

Thanks so much for the responses! I have to say that I'm not really a pellet stove mechanic, and I was just guessing on the feed motor going bad. Really have no clue, and that's whY i figured I would ask those that are in the know!

I'm so glad you guys have given me such detailed responses. I am going to stick all of them together and forward them along to the homeowner having the problem!

 

[pelletheat]

When they fill the hopper with pellets, do they try to squeeze a few extra pounds of fuel in the hopper by packing the pellets in? This will cause the pellets to pack tightly and bridge(I learned this from personal trial & error). Have them check the length of the pellets they are using. if they find pellets longer then 1 1/2" mixed in the bags, extremely long pellets would also cause problems with pellets bridging. PFI lists 1 1/2" as the maxium length and with all the the "new" pellet manufactures this season, the quality of pellets they are using may be the culprit.

 

[moog5]

That happend about 4 or 5 time to me last winter with my xxv. When I stuck my hand through to the bottom of the hopper, it seemed to me the pellets were bridging, because it fixed the problem when I would push them down and across the slide plate.

I cleaned the feed mechanism (per the manual and as Harry explained) 3 times last year (about once per ton), and never found it to have much of any fines, so I don't think that has anything to do with it. My pellets were also always dry. I am guessing it has to do with the shape of the hopper, and the sides not being steep enough to allow pellets that are longer than the PFI length of 1-1/2" to keep from bridging. I know the brand I use (GF) has quite a few a bit larger than 1-1/2". Could there be something else that might be causing the slide plate to stick?

 

[HarryBack]

possibly, Pete. Pull out the slide plate, its behind that wingnut fastened plate. Look at it. Is it clean, or does it have black/brown residue on it? When putting the plate back, make sure you re-engage the plate in the drive mechanism or you wont get any pellets to feed. Good luck!

 

[drizler]

Sounds like rat holing to me. Like stinky feet it happens to the best of us. Brand of pellets and amount of dust and fines in there make the difference. Not a big problem just one of those things to deal with. Sometimes mine gets clogged up and binding with corn and / or pellet fines. Try running it empty then removing the auger and cleaning up the tunnel it sits in. If it persists it could be the auger motor though. I took mine apart once and there are a lot of gears in there to get busted off. Maby, possibly; and this is only a supposition one of those teeth on one of those gears is broken or blunted and binding or not engaging the opposing gears teeth. If something got caught in the auger once like a nail or whatever it could cause damage, especially if it was removed wrong. There is a lot of compound leverage in that motor gear box setup. Auger motors aren't all that expensive and easy enough to replace. Of course this is just supposition I don't do this for a living. When I broke mine the teeth were truly busted so take it with a grain of salt, rather just something to consider. When all said and done I would try stirring the pellets with my hands after filling the hopper fully and seeing how that worked out, keeping it more than 1/4 full since the weight of the pellets tends to push down and keep the feed going ect. I know mine can get hung up sometimes but its always when its nearly empty.

 

[GVA]

That happend about 4 or 5 time to me last winter with my xxv. When I stuck my hand through to the bottom of the hopper, it seemed to me the pellets were bridging, because it fixed the problem when I would push them down and across the slide plate.

I cleaned the feed mechanism (per the manual and as Harry explained) 3 times last year (about once per ton), and never found it to have much of any fines, so I don't think that has anything to do with it. My pellets were also always dry. I am guessing it has to do with the shape of the hopper, and the sides not being steep enough to allow pellets that are longer than the PFI length of 1-1/2" to keep from bridging. I know the brand I use (GF) has quite a few a bit larger than 1-1/2". Could there be something else that might be causing the slide plate to stick?

I'm still a bit confused here. I'm not sure if the feed throat of all harmans is the same but on mine I just looked at it The hopper is almost MT it looks like I could stick the end of a 2X4 in it. Now here is the interesting part of it. I shut the stove down earlier today so it burned itself out, when I just went to see the size of the feed throat I pushed pellets aside and heard them droppin to the auger, now one would think that this would mean the auger was MT and maybe there was a bridge in there but I know that there wasn't.
My earlier post is just a way of troublesooting if the stove shuts down by itself and you get what is called the 6 blink status, in my cases the stove runs out of pellets and you get the blink. Now if I turn the stove off and then back on I will get the 6 blink again because I still havn't added any pellets.

So my sugestion was and still is if you wake up in the morning and have the 6 blink going and the hopper is full PLEASE resist the temptation to swish pellets around and just turn the stove off and back on and see if it takes off again if it doesn't... then do the swish thing. BUT if it does there could be a problem of incomplete or poor combustion and per the manual " poor or incomplete combustion is a contributor of creosote and may cause a chimney fire". Just trying to narrow it down a bit.
And on a side note I've pulled open that cover for the slide plate and at most got a tablespoon of fines after a ton of pellets just like you Pete. :coolsmile:

 

[HarryBack]

could be the gearmotor...dont think its the auger.....screw-type, by design there cant be clogs of fines or pellets there. I took a gearmotor apart once....huge amount of gears in there...counted like 17....the primary gear was plastic or nylon, and yea, teeth can get stripped off of it, giving you sporadic operation.

As for the wingnut cover....it'll fill eventually, and it takes a year or two of burning to do so, but we find folks rarely clean this...eventually, tehre is so much dust in there it inhibits the feeder arm from moving, thusly no feed.

Yea, most of the "throats" to the auger are roughly the same size.
Yea, the area under the slide plate is usually somewhat empty, so you should hear the "tinkle'tinkle" of pellets when they fall in there during feeding.

Have you got an initial draft reading and a recent one? You can compare the two as see if there isnt a plugging issue of the exhaust system somewhere.

 

[Corie]

Harry, is that draft reading comment still for me?

Just want to be sure.

 

[GVA]

Harry, is that draft reading comment still for me?

Just want to be sure.

Have you heard back from the neighbors yet?
And yes the draft reading could be for you, again if draft is off incomplete combustion can cause the stove to shut down and should give you the 6 blink status thats why I keep mentioning to turn stove off and then back on and see what happens.
If the draft is off have they cleaned the combustion blower fins, its probably the hardest thing to clean on the stove?
Heres another idea if they move the feed knob to test after this happens do pellets feed out of the auger to the burn pot right away? If they do it definitely is not bridging.

 

[Corie]

I need to somehow merge all of this into a word document and forward it over to them.

I guess I'll get started on that right now.


Thanks again all!

 

[HarryBack]

Id be curious, Corie, if there is a difference between the initial draft test reading when the stove was installed, versus now, when there *might* be a problem.