ESW EP-25 incomplete conbustion

[GuitsBoy]

Hello and happy holidays -

I have a new issue thats been developing with my fairly new stove. It seems im getting some sporadic incomplete combustion. Occasionally the burn pot will fill up overnight and back up all the way up to the auger chute. This of course scares me, as I do not want to start a hopper fire while we are asleep or out.

Symptoms:
Burn pot fills up and overflows, backing up into the chute
Classic "baking brownies" at the bottom of the burn pot
The stove will burn clean for hours and hours, and then may overflow all of a sudden in two hours time or so
The stove may overflow as quickly as 6 hours after a daily scrape and vacuum
I have only burned 1/2 to 3/4 ton pellets on the new stove
Auger moves every 7 seconds even on low heat. I seem to remember it being closer to 15 second intervals when I first installed it.

Troubleshooting Ive done:
Tried 3 different brands of pellets
Plates off cleaning, very little buildup
Checked vent pipe cleanout, checked OAK intake
Checked gaskets, everything seals fine, seam might be a small leak
Ground welding flashing off burn pot bottom lip for a better seal
Bumped low burn airflow up to 6, problem either remained the same, or got worse, so its back to 4. (at sea level)

Any suggestions on what I can try next? The only other thing I can think of is that some pellets occasionally fall down into the airwash slot up front, and they can be difficult to remove. I havnt disassembled this part, and truthfully I don't even know if it can be removed.

Thanks for any suggestions.

 

[kofkorn]

A few things I've found that may be of help:

- Did you remove and clean the combustion blower? The ash that cakes underneath the blades makes a significant difference in how much air the blower moves. I clean the blower as a part of each full cleaning.

- Clean the whole vent pipe, it's not as much as the diameter restriction, as the rough surface caused by the ash in the entire pipe that reduces airflow.

- Especially check the vent cap. With the significantly cold weather we've had lately, it is possible that some condensing can occur at the end of your venting. I had a cap close up on me and it immediately caused the issues you are seeing.

- Use an appropriate sized drill bit to clean out the holes in your burn pot.

Overall, you are likely seeing some kind of air flow issue.

Good luck!

 

[GuitsBoy]

Thanks for the suggestions. Ill reply in order:

I did not remove the combustion blower yes, as the stove is new and only has 25-30 bags through it. Do you think the blower could clog up so quickly?

The vent pipe is one horizontal section through the wall to the cleanout T, then 4 sections up to the bend and vent cap. While looking up the cleanout, everything is coated in fine soot, but nor rough clumping yet.

Vent cap is fine, no clumping. Its been in the 50s the last 3 or 4 days, so its certainly not frozen condensation.

Burn pot is clean. While I do scrape off some deposits on the burn pot surface with a chisel, the holes are not obstructed at all.

Do you think it could be a small gap by the rope gasket seam? The overlap section looks a little weak, and it looks like there may be a small gap about 1/16 inch.

 

[kofkorn]

Any gaps in the gasket certainly won't help. It should really overlap by some amount to prevent any leakage. It might be a good idea to use a smoking match or some incense near that gap to see if the smoke is being pulled into the stove. I don' have this model stove, but typically if you were having a feed rate issue, where the auger is turning too much, you should be having a blazing fire, and tripping the overtemp limits on the stove. I would step through the entire intake, stove, and exhaust chain point by point to make sure there are no restrictions. Then start looking for areas of potential vacuum loss.

Maybe someone else can give a little more stove-specific suggestions.

 

[GuitsBoy]

Thanks, Thats pretty much my plan. Im gonna have to pull it all apart and see if theres anywhere I cant see thats clogged up. Hard to imagine it would need the blower motor pulled after such a short time, but its the only way to rule it out as the problem. Ill inspect the gaskets and seals everywhere, then do the smoke test on startup, that way the convection blower isn't interfering.

Thanks for the suggestions.

 

[Rubicon 327]

Watching this closely as my refirb/ new 25PDV is doing almost exactly the same thing. I also have burned just about as many bags as you have as well Guitsboy.

Any setting mine backs up like this. This was cleaned out this morning at 6am....8 hours later and it is backed up. Running on Heat setting of 4 & a Fan speed of 9.

Is this about how your burn pot looks Guitsboy?

 

[ericofmaine]

Watching this closely as my refirb/ new 25PDV is doing almost exactly the same thing. I also have burned just about as many bags as you have as well Guitsboy.

Any setting mine backs up like this. This was cleaned out this morning at 6am....8 hours later and it is backed up. Running on Heat setting of 4 & a Fan speed of 9.

Is this about how your burn pot looks Guitsboy?

That's exactly how my PDV looks after about that much burning. After reading on here, it seems normal. I just have a metal spatula by the stove and once a day or so, scoop the ash into the ash pans on the side. I may eventually try a gasket under the burn plate to see if that helps.

Eric

 

[GuitsBoy]

I cant believe I spelled it conbustion! Uggghhhhh

Thats pretty similar Rubicon. Though bleeding off that much heat with a fan setting of 9 might not be helping matters. Like a car engine, it may run a little better if you let it get up to temp.

 

[kofkorn]

Though bleeding off that much heat with a fan setting of 9 might not be helping matters. Like a car engine, it may run a little better if you let it get up to temp.

I would go the opposite way. The speed of the combustion blower is affected by the feed rate, not the room fan setting. I keep my room fan on 9 at all times, because this strips the most heat out of the exhaust and keeps it in your room instead. By lowering the room blower speed, you're just sending BTU's up the exhaust.

The room blower should not significantly affect your flame pattern.

 

[GuitsBoy]

I didnt meant to imply that the the room blower setting affects combustion airflow. But it does affect the operating temperature of the stove. I would think that anything that cools ash down too quickly would help lead to deposits and brownies in the burn pot, since the ash cools before its fully burned up and light enough to be carried away by the combustion airflow. But the flip side is that running too hot leads to other issues, annoyances, and decreased component life. I have to play a delicate balancing act with fan speed to keep the stove hot enough to get a more complete burn, but not so hot the auger starts squeeking at me (my other issue/thread)

 

[Rubicon 327]

Thanks Eric I will just scoop them out and try some mods like you mentioned as well to try and get a better burn.

 

[kofkorn]

There are a few tricks some people use (Myself included) to increase the amount of air going through the burn pot. Some people use steel wool to block the two holes underneath the wear plate on the lower sides of the burn pot. These holes allow some of the air to go over the top of the burning pellets. I've built a "U" shaped insert out of sheet metal that I will slide forward and back to cover or uncover these holes. It gives me a little more adjustability than the steel wool does.

Take a look at this thread for some suggestions: https://www.hearth.com/talk/threads...ng-from-d-mode-to-c-mode.117151/#post-1572131

good luck!

 

[Rubicon 327]

Thanks for that info Kofkorn!

I will have to give that a try and see how it works.

 

[GuitsBoy]

Made some progress last night...

I have routinely been removing the plates every two weeks as suggested in the manual. The ash has never even been close to the bottom of the cleanout port. However after using a small length of hose to get behind the baffle, this seems to have helped improve airflow greatly. Also fixing a small gap where the door gasket ends meet helped as well (they dont overlap very well). I plan on adding a small section of rope gasket as a permanent fix.

Thanks again for the help.

 

[Jason Knapp]

I had a similar situation with my EP. First i made sure the burn pot sat completely flush in the cradle. This took some massaging with a hammer to achieve a perfect seal. I then welded the top rows of holes shut on the burn pot. I also welded the big hole on the left of the burn pot closed, opposite of the igniter. I finally choked my air wash by about 50% with fiberglass rope.
I also found a large gap between the stove body and the hopper lid on the control board side. I also used fiberglass rope to build up this area. I also ran the stove and traced the gasket areas with a grill lighter. My ash pan had a sizeable leak. I rolled the edges of the pan slightly with wide billed vise grips and doubled the gasket on the bottom face of the pan, not the angled pieces though.
My stove runs for days before it needs to be cleaned. Give it a try. If you want pics, I can post them.

 

[Lake Girl]

Nice Jason - lot of good tips for improvement. Worthy of a sticky link like the one for Harmans

 

[Jason Knapp]

Thank you

 

[GuitsBoy]

I had a similar situation with my EP. First i made sure the burn pot sat completely flush in the cradle. This took some massaging with a hammer to achieve a perfect seal. I then welded the top rows of holes shut on the burn pot. I also welded the big hole on the left of the burn pot closed, opposite of the igniter. I finally choked my air wash by about 50% with fiberglass rope.
I also found a large gap between the stove body and the hopper lid on the control board side. I also used fiberglass rope to build up this area. I also ran the stove and traced the gasket areas with a grill lighter. My ash pan had a sizeable leak. I rolled the edges of the pan slightly with wide billed vise grips and doubled the gasket on the bottom face of the pan, not the angled pieces though.
My stove runs for days before it needs to be cleaned. Give it a try. If you want pics, I can post them.

That is a good bit of info. Ill give a few of these a shot, although I may try something temporarily before breaking out the mig welder. Thanks

 

[Jason Knapp]

I'm sure by starting off with checking the ash pan seal quality and burn pot to cradle fit will make a sizeable difference in how your stove runs.

 

[AddictiveStew]

I have all these problems as well. I've been doing all kinds of things to try to remedy the issue. I had to add a small section of gasket to the left side of the door (placed it on the stove itself) to fill the gap in the door. This was after I replaced the door gasket and it still didn't make a complete seal. My stove also came with a crooked hopped lid and I had to build up the gasket on the control board side to compensate. I hate to say that I'm relieved to read this post but I am. I'm going to try to partially block the airwash and I also noticed a sizeable leak around my ash pan. I can usually force it into place, but it undoubtedly flexes over a few hours and lets some air in i'm sure. Overall this stove arrived with leaky seals, a crooked door, and a warped burn pot. In fact, I feel like the entire stove is warped with the door not making a good seal on the left hand side and the hopper being crooked and not sealing on the right. It's been an uphill battle trying to get it to burn right. I feel your pain. I'm closer than ever though (at least I think).

 

[Jason Knapp]

I have all these problems as well. I've been doing all kinds of things to try to remedy the issue. I had to add a small section of gasket to the left side of the door (placed it on the stove itself) to fill the gap in the door. This was after I replaced the door gasket and it still didn't make a complete seal. My stove also came with a crooked hopped lid and I had to build up the gasket on the control board side to compensate. I hate to say that I'm relieved to read this post but I am. I'm going to try to partially block the airwash and I also noticed a sizeable leak around my ash pan. I can usually force it into place, but it undoubtedly flexes over a few hours and lets some air in i'm sure. Overall this stove arrived with leaky seals, a crooked door, and a warped burn pot. In fact, I feel like the entire stove is warped with the door not making a good seal on the left hand side and the hopper being crooked and not sealing on the right. It's been an uphill battle trying to get it to burn right. I feel your pain. I'm closer than ever though (at least I think).

Don't give up! Once your issues are resolved you will certainly love your stove. I love my 25 EP! I wouldn't trade it for anything!

 

[AddictiveStew]

Don't give up! Once your issues are resolved you will certainly love your stove. I love my 25 EP! I wouldn't trade it for anything!

Believe it or not, partially blocking the airwash actually seems to have fixed the issue! Ash is now getting ejected from the burn pot and the stove barely used any pellets all night and kept the house warm! There is zero buildup in the burn pot now. Fingers crossed it continues to work this well!