XXV gummy stove gets me

[Pellet_Pete]

Preface: Started getting smoke in my hopper earlier this year which is a problem from older Harman XXV's, but I figured the fix could wait til spring. I attributed this sudden onset of smoke-in-hopper to one or both of me adding an OAK and reducing my draft dial all the way, per use of magnahelic gauge as described in the manual. For those who hopefully never need to know first-hand, smoke-hopper-syndrome ultimately leads to gummy stove disorder whereby smoke residues gum up the auger & slide plate - fun!

Fast forward to now - it's 4am and I've just got my XXV fired back up. Woke up to an old familiar lack of distribution fan sound, and found the stove all but fired down. Test mode yielded strange noise from feed mechanism, so I presumed auger jam. Emptied hopper & opened fines box - vacuumed both out as best I could. Now, something funny about the fines box is I haven't been getting any fines in there...here's why. I finally figured out how get the slide plate out and discovered a wall of gummed up fines that was blocking any new fines from entering the collection box. Oh, and the slide plate looked like a glazed ham! (I briefly thought about taking a picture of it for this forum, but then I remembered it was probably nearing -10 outside) Washed it off (that gunk washes off handily in warm water), and I even scrubbed around with damp cloth inside the hopper where the slide plate slides. Put it all back together - and disconnected my OAK - and dialed the draft back up to where it was last year - and all seems well for now.

As for gumminess, the auger *sounds* somewhat labored, so I presume the auger shaft is a little sticky and will need a scrub. Hopefully that can wait until spring! Fortunately, I have the P61A in the basement, saving me and my family from a quick chill! Took 2 hours without the XXV, and house was still 67 with the P61A set to Room Temp 80 degrees.

My heart's resting a little easier...for now.

 

[Pellet_Pete]

Periodically I still hear a "clink" which sounds like the slide plate coming unstuck as it slides. Going to be mid-twenties - might be a good day to pull auger...

 

[alternativeheat]

Your whole post is news to me. I had no idea early XXV's had gummy issues, smoke issues etc. Had no idea that with OAK you needed to turn down your draft trim. Let us know how this all goes ultimately.

 

[canuck_22]

So this issue has been corrected with newer XXvs?

 

[bogieb]

Glad you had the P61a to help keep the upstairs warm while you figured out the issue with the XXV!

 

[Pellet_Pete]

Well, stove shut down again so problem must be addressed today! Ugh!

There are lots of old posts on gummy stove circa 2009. My understanding is after 2007 or so the feeder body design changed &accounted for the issue.

 

[Pellet_Pete]

Progress Report: Removed auger and discovered the true state of things
Auger totally plaqued up with a fine past of sawdust and condensed woodsmoke. Second pic is looking down auger tube from back where you can see an even more heinous accumulation of fines & "tar" blocking up the "drop zone" from the hopper. Reason stove shut down - pellets could no longer pass through this thicket of nastiness!


Soaked the auger in warm water & the gunk came right off with a putty knife and stiff pipe cleaner. Here's the auger drying in front of the P61A.


I've been chipping away - more like gooping away - at the stuff up above the auger shaft, mostly using a screw driver. Buildup was predominantly on the fines box side of the chute, since my slide plate was gummed up and not discarding fines anymore. Here's one of the globs of "cookie dough" I pried out.


The drop chute isn't totally cleaned, but it's certainly functional again.

Last task is the auger tube, which has a very tough, compressed buildup of the same stuff, also on the fines box side. I've been alternating between a wet rag wrapped around a pipe cleaner and a stiff wire brush, which is wicked slow. I think the right tool would be a proper 2" wire pipe cleaner, preferably on a flexible drive shaft (don't have either of those presently). We'll see how it goes...Looks like I should be able to make fire tonight at least. Phew.

 

[alternativeheat]

Ugly ! How difficult is that auger to pull out ?

Just thinking, would heat melt that crud down then swab it out with damp rags on a shaft attached to a drill ? Run that through the tube.

 

[Pellet_Pete]

Ugly ! How difficult is that auger to pull out ?

Just thinking, would heat melt that crud down then swab it out with damp rags on a shaft attached to a drill ? Run that through the tube.

Auger was actually easy to remove - had never done it before. Turning it manually I could really feel the constriction.

I don't about applying heat to this stuff - I'm guessing its flammable!? Until my wife gets back to watch kids, I'm trying wet steel wool - does something but boy is that some stubborn stuff!

 

[alternativeheat]

Auger was actually easy to remove - had never done it before. Turning it manually I could really feel the constriction.

I don't about applying heat to this stuff - I'm guessing its flammable!? Until my wife gets back to watch kids, I'm trying wet steel wool - does something but boy is that some stubborn stuff!

I was thinking maybe a hair dryer not direct flame. Enough to melt the resin, if it works like that. What a mess ! By cleaning now you might have saved yourself a motor if it was dragging that bad.

 

[Tonyray]

I was thinking maybe a hair dryer not direct flame. Enough to melt the resin, if it works like that. What a mess !

haven't read anywhere what Pellets the OP has been burning out of curiosity..

 

[Pellet_Pete]

haven't read anywhere what Pellets the OP has been burning out of curiosity..

Fireside Ultra all year, 3-4 tons in.

 

[3650]

I would try one of those small steam cleaners. I think they are called "the shark" or something. Those things really cut through gunk.

 

[Pellet_Pete]

Well, I got it as clean as I had patience for, put it all back together reconnected the OAK, and cooked through a whole hopper full of pellets overnight (house was 75 when I got up!). No smoke in hopper, no shut-downs.

I don't know which is the chicken or the egg, but having the holes in the slide plate gunk up so that all the fines were pushed down to the auger really made things a lot worse, and fast! It's a bit of a pain to empty the hopper, but I just might do that every other cleaning now. I can't see how the OAK would have affected the smoke-in-hopper, hence reconnected it. I suspect lowering my draft might have tipped the balance this year, so I won't b messing with that again.

At season's end, I'll be looking to implement the "solution to gummy stove syndrome" as posted here:
https://www.hearth.com/talk/threads/harman-accentra-gummy-stove-syndrome-solution.45548/

 

[Pellet_Pete]

Oh yeah - once I put everything back together last night, put it to test mode & my distribution fan didn't work! Almost lost my mind, but further investigation (after removing cleaning & re-testing the distribution fan) revealed that one of the wires connecting to the back of the control board had stripped out of its connector tab. Now that was a nice, clean easy fix!

 

[alternativeheat]

Well, I got it as clean as I had patience for, put it all back together reconnected the OAK, and cooked through a whole hopper full of pellets overnight (house was 75 when I got up!). No smoke in hopper, no shut-downs.

I don't know which is the chicken or the egg, but having the holes in the slide plate gunk up so that all the fines were pushed down to the auger really made things a lot worse, and fast! It's a bit of a pain to empty the hopper, but I just might do that every other cleaning now. I can't see how the OAK would have affected the smoke-in-hopper, hence reconnected it. I suspect lowering my draft might have tipped the balance this year, so I won't b messing with that again.

At season's end, I'll be looking to implement the "solution to gummy stove syndrome" as posted here:
https://www.hearth.com/talk/threads/harman-accentra-gummy-stove-syndrome-solution.45548/

Glad it's all up and working ! Sounds good, nice temps in the house.