Harman Advance going lazy after a week

[zinfendel]

I installed this stove Jan 2013 and used it a little bit that winter. This winter I heated my house exclusively with it Oct and Nov, and burned a ton during those months. Into December I used it to augment my natural gas baseboard heat... and until the last couple weeks, it ran fine. A bit over a week ago I noticed a lazy flame and blackened glass. It was also pushing lots of unburned pellets into the drawer; previously I had a nice inch of soft gray ash at the edge always. In fact in Nov I emptied the ash drawer for the first time after burning 1500lbs! But now the flame was real lazy.

I did a fairly complete clean on it, burn pot, overheat exchangers, cleared the airholes on the burnpot, cleaned out the inside of the combustion blower. I looked through the horizontal vent from inside, and it wasn't bad at all. With a lot of snow outside, I didn't want to hook up my outside vac and brush out the vent. Outside I go through-wall, then vertical about 5', then a snorkel vent cap.

One thing I did notice was a bit of soot at the top of the opening face of the stove when the door was open. Right where the seal pressed up against it. Is the seal leaking? I am not getting any smoke in the house that I can notice.

Anyway, it lasted a week+ after that clean, then last night, lazy flame again, smoked up glass, pushing unburned pellets, etc. So I shut it down last night.

Thoughts? We will have warmer weather and less snow, so I will look at the vent this weekend. Could it be the door seal? Just seems odd that it ran so well for all that time, then all of a sudden this. My second ton started Dec 1, was the same pellet brand BTW (Supreme Green I think), and I will say that even when it was running well, it seemed to fill the ash pan up faster than the first ton.

 

[Defiant]

Check out the air intake flap in the back to make sure it moves freely. Sounds like it is not getting enough air.

 

[kinsmanstoves]

It is an airflow issue. If it is not sometype of obstruction in the stove I would ditch the 5' vertical and see what happens.

Eric

 

[zinfendel]

Thanks for the tips. I checked the intake air port outside (it has outside intake air) as well as the vent, and that does not seem to be any problem. I did a quick clean, and fired it back up. Coincidentally, I just today got a magnehelic gauge that I ordered on eBay, so a few minutes after I got the stove going, I took the bolt out and measured it at around 0.2". It ran ok for a while, but after a few hours, I can see the "ash edge" off the burn pot looking not so nice. Not the 1" of ash that Harman says should be there. Another few hours and I bet it will be pushing unburned pellets over into the drawer again.

Question, Advance specific: I can take the plate off the combustion blower and see the outbound aperture to the vent. Where is the air drawn into the firebox from?? Is it all drawn from the holes in the burn pot? Or somewhere else? Again, I had a soot-smear at the face of the stove, where the door seal meets up, so I am wondering about seals. I bought this stove used, it is now 11 years old. Maybe I should replace the seals?

 

[Defiant]

That could be your problem. I would change the door gasket it probably has a leak by being worn and interferes with the vacuum.
The combustion air comes from the opening above to the right of the exhaust there is a pipe with a flap on it, do you have OAK? If you do there will also be a liner on the intake that goes outside. Post pics it will help.
(broken image removed)

 

[zinfendel]

Yes, I have an OAK, will post pics this weekend.

 

[Bioburner]

Bad seals- gaskets can start to effect things after the stove warms up. Did you check vacuum after things got warmed up? 11years on a set of gaskets is pretty good. Easy to replace and not very expensive even with a purchase of a drill powered wire wheel. $20 +-

 

[zinfendel]

Still puzzled by this. The magnehelic reads 0.6" on "Test" on a cold stove, spec is at least 0.5". It reads 0.2" once I turn the stove on. Left the gauge on it for hours, it stayed right on 0.2" constantly. So does this mean that the gaskets are not leaking significantly? I will probably replace them anyway.

The flame is not super lazy, but after a half hour or so, the auger starts pushing unburned pellets over the edge. I now have the max pellet feed all the way down to 1, and there is a narrow ash edge there, but the stove isn't running very hot.

Trying to understand root cause there, this thing ran perfectly for a long time. Maybe somewhere I didn't clean good? How does the air get into the box and back out? I know where the combustion blower exhausts it out the vent, but the ash drawer seems to block it? I know where the intake is outside the stove, but where does the air get drawn into the box? Via the holes in the burn pot? Just trying to understand the flow of air through the stove. I don't feel much airflow out of the vent pipe either. Not like I remember when it is cranking...

I will take the back panels off and make sure that the intake air flap is free.

 

[P38X2]

Is your combustion impeller clean? Check that.

Air gets drawn in through the intake in the back of the stove and through the flue area you can see when the cover is off the front of the pot. Air gets SUCKED through the pot holes (through the burning pellets) via the combustion impeller and then pushed out of the exhaust vent.

 

[chken]

I installed this stove Jan 2013 and used it a little bit that winter. This winter I heated my house exclusively with it Oct and Nov, and burned a ton during those months. Into December I used it to augment my natural gas baseboard heat... and until the last couple weeks, it ran fine. A bit over a week ago I noticed a lazy flame and blackened glass. It was also pushing lots of unburned pellets into the drawer; previously I had a nice inch of soft gray ash at the edge always. In fact in Nov I emptied the ash drawer for the first time after burning 1500lbs! But now the flame was real lazy.

I did a fairly complete clean on it, burn pot, overheat exchangers, cleared the airholes on the burnpot, cleaned out the inside of the combustion blower. I looked through the horizontal vent from inside, and it wasn't bad at all. With a lot of snow outside, I didn't want to hook up my outside vac and brush out the vent. Outside I go through-wall, then vertical about 5', then a snorkel vent cap.

One thing I did notice was a bit of soot at the top of the opening face of the stove when the door was open. Right where the seal pressed up against it. Is the seal leaking? I am not getting any smoke in the house that I can notice.

Anyway, it lasted a week+ after that clean, then last night, lazy flame again, smoked up glass, pushing unburned pellets, etc. So I shut it down last night.

Thoughts? We will have warmer weather and less snow, so I will look at the vent this weekend. Could it be the door seal? Just seems odd that it ran so well for all that time, then all of a sudden this. My second ton started Dec 1, was the same pellet brand BTW (Supreme Green I think), and I will say that even when it was running well, it seemed to fill the ash pan up faster than the first ton.

You burned over a ton, since the install, and it doesn't sound like you've ever done a thorough vent clean. A vent can look not bad, but when the flame goes lazy and the glass goes black, the first thing I would consider is a dirty vent.

 

[Don2222]

After burning a ton of pellets the trap door under the burn pot needs to be cleaned of ash.
Have you done that?

 

[zinfendel]

Thanks for the tips. That is where I thought the air came into the burn pot.

"The trap door under the burn pot"? What is that? I have taken the cover off the front of the burn pot and vacuumed the cavity out a bit, but never really looked at it close. Back where the ignitor is, right? Is that the door that is on the intake port that I could see from the back when I installed the stove? Not sure I know how you can see in there from the front, but I'll shut down the stove tonight and have a good look tomorrow.

I did do a thorough vent clean at the start of this season, and the yes, the comb. fan impeller is clean.

Still unclear how the air inside the box gets to the combustion fan/vent, it looks like the ash drawer blocks that off? Am I missing something?

 

[Bioburner]

Make sure to carefully clean the ESP in the exhaust path. That little probe can be a real pain in keeping the stove running proper.

 

[kinsmanstoves]

I would look at the feeder assy access cover to make sure it is correctly on.

Eric

 

[rickwai]

Also w/ the mag hooked up watch the reading and press on the door on different areas and see if the mag reading jumps.

 

[briansol]

A week is about all I get before my flame goes lazy too, mostly due to build up, ash, etc etc. Honestly, it sounds normal to me. clean it.

 

[zinfendel]

Well embarrassingly, I found the issue. I really didn't understand the airflow path of that stove until last weekend. I knew the air came in under/through the burn pot, but the path it took to get to the combustion blower and out the vent was a mystery until now... I realized going back into it that that path was over the top of the back plates and then down the ash drawer/blower area by way of the exchanger behind the back plates. The first time I cleaned the stove, I took it all apart, but the last time, I didn't take the back plates off and clean back there. Totally choked with ash. Gave it a good, proper cleaning and now it is burning strong again. Well, at least I got a new tool (magnehelic) out of the deal.... Thanks for all of the tips..

 

[Defiant]

A clean stove is a happy stove

 

[rickwai]

A low mag reading means plugged from burn area to end of vent or gasket. Extreme high reading is restriction in air from back of stove to the outside.