# PB105 and PF100 burn pot hump and crack failure



## exoilburner (Feb 18, 2010)

Thanks for your help to find some answers to the burn pot problem in the Harmon PB105 boiler and PF 100 pellet furnace by participating in this poll.  It seems to happen only to this burn pot.  Same part number used in both units.  The Harmon stoves don't use this burn pot and I've not seen any posts with this problem in their stoves. 

The problem shows up as a hump forming in the middle of the burn pot air holes above the igniter location and deteriorates to cracks between the air holes. It seems to appear in my unit once or twice a during burning season. Other owners are also having this problem.  But some are not.  Maybe the reason for the difference can be found and a fix determined from the posts in this poll.  Good information would be how owners run their PB105s and PF100s, settings, install, and what ever info. might help.

Please don't vote in the poll if your PB105 or PF100 is new and has not run for at least a full season. 

It would be helpful to know wether or not you are having the problem and post information about how you run your unit.


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## Wayne64SS (Feb 19, 2010)

Dude I voted no, but i looked today closer and there is a hump it's just not real big so i never noticed it. FML.


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## exoilburner (Feb 19, 2010)

Wayne64SS said:
			
		

> Dude I voted no, but i looked today closer and there is a hump it's just not real big so i never noticed it. FML.



Wayne thanks for the vote. Keep an eye on your burn pot because thats the way it starts. First looks like a little warping in the middle of the burn pot air holes. Gets worse, forms a hump there over the igniter area, and starts getting cracks between the holes.  

I have a picture of a bad burn pot and will post it if you need to see what this looks like.

If your burn pot gets the hump, vote again and let us know how you operate it, your settings and install info. Looks like nobody has figured out why this is happening on some PB105s and PF100s but is not happening on others. Need to figure it out before our warranties expire.


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## ghangac (Feb 19, 2010)

This is my 2nd season with the PB-105.  I noticed a small hump developing towards the end of last season.  It is now much more noticeable, and you can see the holes are starting to get larger ontop of the hump.  My first ignitor burnt out after one season of operation in the automatic mode.  Hope this helps, look forward to reading other responses.


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## exoilburner (Feb 19, 2010)

ghangac said:
			
		

> This is my 2nd season with the PB-105.  I noticed a small hump developing towards the end of last season.  It is now much more noticeable, and you can see the holes are starting to get larger ontop of the hump.  My first ignitor burnt out after one season of operation in the automatic mode.  Hope this helps, look forward to reading other responses.




Check out these two links for an ongoing discussion about the same issue:
http://forum.iburncorn.com/viewtopic.php?t=12709
http://forum.iburncorn.com/viewtopic.php?t=12779


Does your burn pot look like this one?  Is the hump with enlarged holes in the same area of the burn pot?
If it looks the same could you post your settings, outside air, install setup, and how you run it.  And any suggestions.


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## Former Farmer (Feb 20, 2010)

I had just replaced my burnpot a couple of weeks ago. Boiler was manufactured in oct 2008. That was the original burnpot, lasted just over one year. I had waited until the bubble started to crack. If the bubble forms again, I will not wait that long! The ignitor is located on the underside of the burnpot in my boiler. Still original ignitor. Run unit in auto mode all the time. Have the OAK and OAT both connected.


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## ghangac (Feb 20, 2010)

exoilburner,

My burn pot is no where near as bad as the one in the photo. I think mine is at the early stage of getting there. Attached are photos of my burn pot. 

My settings are as follows:
Feed Rate 3.5
Low 145
High 165
Dip Switch #2 set to “ON” for slow feed rate on start-up.

I would think that the ignitor is causing the problem, because it is located directly below the hump. Maybe the heat from the ignitor during start-up is changing the characteristic of the metal, and then during normal burn the metal starts to break down.


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## exoilburner (Feb 20, 2010)

ghangac said:
			
		

> exoilburner,
> 
> My burn pot is no where near as bad as the one in the photo. I think mine is at the early stage of getting there. Attached are photos of my burn pot.
> 
> ...



ghangac,
Nice pictures.  I was having trouble getting a good shot of the hump (bubble).  Although the hump in yours is small it looks like mine when it starts going bad.  (Centered on the 5th, 6th and 7th row of holes) Thanks for sending your settings.  Hopefully the PB105 and PF100 gang on the forums can find out why some units are having this problem and others are not.  I think Harmon is working this issue too.  Collectively maybe we can come up with some information that will help them.  So far nothing stands out between the good units and the failing units that would give a hint about why some work and some fail.
I had an area rep looking at my PF100 and he was going to look at another PF100 in his area that had the problem.


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## ex-oil slave (Mar 1, 2010)

I'm on my second burn pot. The first lasted the entire first heating season - 7 months and 6 tons of pellets. The dealer said the new burn pot I got was a PB105 burn pot and was supposed to be heavier steel and less likely to warp, but I noticed it's starting to hump up and I still have 2 months to go in this heating season. It does seem to be standing up a little better than the original. I use OAK in a basement.


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## ex-oil slave (Mar 1, 2010)

To Exoilburner.............

It concerns me a bit when you post " Need to figure it out before our warranties expire." Harman is aware of this problem and has already provided warranty exchanges on multiple units. There should be no warranty expiration period for a known manufacturing defect that is under review. When or IF Harman figures out a solution for this, the fix should be provided free of charge to all PF100 owners. Furthermore, since Harman is aware of the problem, I think THEY should be the ones collecting data by contacting all PF100 owners with a questionaire or something to help get to the bottom of it. Don't get me wrong, I appreciate what you and others are doing, it's just that I think Harman should be more proactive. Their "arm's length" policy needs to be modified to fit the circumstances, and I believe that this case warrants them "coming out of their shell" and actually interacting with THEIR CUSTOMERS.


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## exoilburner (Mar 1, 2010)

ex-oil slave said:
			
		

> To Exoilburner.............
> 
> It concerns me a bit when you post " Need to figure it out before our warranties expire." Harman is aware of this problem and has already provided warranty exchanges on multiple units. There should be no warranty expiration period for a known manufacturing defect that is under review. When or IF Harman figures out a solution for this, the fix should be provided free of charge to all PF100 owners. Furthermore, since Harman is aware of the problem, I think THEY should be the ones collecting data by contacting all PF100 owners with a questionaire or something to help get to the bottom of it. Don't get me wrong, I appreciate what you and others are doing, it's just that I think Harman should be more proactive. Their "arm's length" policy needs to be modified to fit the circumstances, and I believe that this case warrants them "coming out of their shell" and actually interacting with THEIR CUSTOMERS.



Couldn't agree with you more.  But, my dealer talked to the Harmon area rep and was told they were working on this but when an owner's warranty ran out the owner would be responsible for the expense of replacing bad burn pots.  He was giving me the bad news.  

This concerns me too; that's why I hope owners will be proactive and involved in getting this resolved.  And give it some public exposure.

I have been considering sending a dated, "signature required" letter to Harmon to establish the fact that my unit had failed during the warranty period and that replacing burn pots was not the solution to a known design problem.  The on going expense for this problem should be theirs not the owners.  I'm going to talk to my attorney and find out how to do it right the next time I experience this failure.


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## ex-oil slave (Mar 1, 2010)

Let me know what you find out. I'm willing to do the same from my end if there is any point to it.


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## exoilburner (Mar 1, 2010)

ex-oil slave said:
			
		

> Let me know what you find out. I'm willing to do the same from my end if there is any point to it.



Will do.  After I talk to my attorney I'll post the info.


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## exoilburner (Mar 23, 2010)

The Harmon area rep and my Dealer tech had been here to look at this problem.  They suspected the igniter; I volunteered to run my PF100 without the igniter because I never use it.  They removed the igniter from the burn pot.  

I called the dealer today and informed the tech that after a month of running without the igniter the problem is still there.  The hump is forming in the same place and in the same amount of time.  My Dealer has a log going and is adding this information to it and will call the Harmon area rep with the info.  He gets updates to the problem resolution if there are any and is good about passing along information.  Will post anything new.


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## exoilburner (Apr 18, 2010)

Found this post from _*wil*_ on a poll on another forum that might be some good news.  That poll is also related to the PB105 and PF100 burn pot bubble forming.

_On 3/24 I replaced another burnpot, on 3/28 a bubble started to form on the new burnpot, I was really pi$$ed, went to see my dealer and mentioned that I thought it was time for Harman to make a burnpot using heat resistant steel such as in the link above. My dealer said he would contact Harman, mentioning to them my thoughts. I talked to him last week asking what Harman is going to do about the burnpot issue, are they going to make one out of heat resistant steel. He told me that Harman is going to manufacture one out of stainless steel, I'm in hopes that it is heat resistant stainless such as in the link below.  
(next post)From what my dealer has mentioned, the new boilers even with the factory installed pressure ignition are having this same issue with burnpots. The thought from Harman was this pressure ignition was going to resolve the burnpot issue but it didn't so now they are going to make the burnpots using stainless steel. ( heat resistant I hope or they will continue to have this problem)_
http://forum.iburncorn.com/viewtopic.php?t=12779&postdays=0&postorder=asc&start=45


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## wil lanfear (Aug 29, 2010)

*UPDATE:*The new stainless steel burnpot, ( the bottom surface only is stainless) was installed in my boiler yesterday, only time will tell if this is the answer to the "burnpot bubble" issue. The understanding that I have from my dealer is, Harman has made very few of these for testing to see if this is going to be the soultion and I was one of the chosen ones to test them. THANK YOU HARMAN.


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## Rosco (Sep 20, 2010)

How is the ss burnpot working for you?

I bought my  PB 105 in August 07.
New burnpot in August 09 due to bubbles. 
Now Sept 2010 and igniter will not lite. Was running fine for last few days but now refuses to ignite.  May have to replace igniter.
Can you tell me about when u replaced yours and why? Should I be looking at replacing it with the pressure igniter u talked about?
 Sorry for all the questions, have been out of the loop with the forums for a year or so and just catching up on the latest with PB 105.


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## wil lanfear (Sep 20, 2010)

rockymoses said:
			
		

> How is the ss burnpot working for you?
> 
> I bought my  PB 105 in August 07.
> New burnpot in August 09 due to bubbles.
> ...


The new SS burnpot after 3.5 weeks of use is working great. I'm checking it every week for signs of a bubble starting to form, to date it is looking good. The original burnpots, after 1.5-2 weeks of use I could measure a small bubble starting to form.

The pressure ignition that was installed in my boiler, under warranty, it was an effort to stop the burnpot bubble issue, it did not resolve this issue. The pressure ignition does ignite the pellets quicker which is a big plus. I suspect the pressure ignition conversion kit may be quite spendy if it was not covered under the warranty.


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## wil lanfear (Oct 18, 2010)

*UPDATE #2* It has now been 7 weeks with the new stainless burn pot installed with *NO* bubble issue, just *MAYBE* this issue is resolved, I sure hope so, more time is going to tell.


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## Rosco (Oct 19, 2010)

New igniter $89.00. Boy does it light alot quicker. Time was cut down by better than half.  I put it in myself about 3 weeks ago and it is working great.

We are averaging 10-12 ton a season to heat a 2400 square ft home with vaulted ceilings. My wife is home all day long and keeps it 74-75 degrees.


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## exoilburner (Oct 19, 2010)

wil said:
			
		

> *UPDATE #2* It has now been 7 weeks with the new stainless burn pot installed with *NO* bubble issue, just *MAYBE* this issue is resolved, I sure hope so, more time is going to tell.



wil,
Thanks for the updates.  I'm sure many of us are following the news about your new burn-pot.  Have you heard anything from Harmon about your results?


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## Former Farmer (Oct 19, 2010)

> wil,
> Thanks for the updates.  I’m sure many of us are following the news about your new burn-pot.  Have you heard anything from Harmon about your results?



X2


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## Hooper (Oct 20, 2010)

I've operated my PB105 for a year now and burned 7 tons (to supplement my FHW Oil, Hearthston woodstove and Russian fireplace) of Ashland Maine pellets (factory burned down last year).  I would never have noticed the bubble and cracking if I hadn't found this forum.  I just checked and sure enough my burn pot is in the early stages of the bubble and has 2 small cracks connecting 4 air hoes.  I found the easiest way to assess it is shine a good flashlight horizontally across the surface and eyeball across the surface and you can easily see what, in my case, I could only feel.  Mine was manufactured 8/08, installed 10/09, I run on auto at varying feed rates (I'm a fan of 6 though).  No outside air or temp connected.  I'm on my original igniter BUT my auger motor locked up and was replaced.


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## wil lanfear (Nov 17, 2010)

*UPDATE #3:* Doing the weekly cleaning today I noticed the stainless burnpot developed a bubble along with a crack between 3 holes. I don't believe the burning surface of the burnpot made from stainless steel is the answer to the burnpot issue. The burnpot has been replaced with the original mild steel one, not the stainless one. My dealer is shipping this one to Harman to evaluate, I hope I have more info after they inspect it.


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## slowzuki (Nov 18, 2010)

I wonder if a ceramic spray coating would help?  Its done in other high temp apps to increase durability of steels at high temp.


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## wil lanfear (Nov 18, 2010)

slowzuki said:
			
		

> I wonder if a ceramic spray coating would help?  Its done in other high temp apps to increase durability of steels at high temp.


Prior to testing the stainless burnpot I mentioned to my dealer my opinion on the material to make the burnpots which he supposed to have passed on to Harman, they decided to make it using stainless steel instead. 

http://www.sandmeyersteel.com/A600.html


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## slowzuki (Nov 18, 2010)

I'm not familiar with how these boilers are arranged or function but exposing a drilled plate like that to heat cycles is expected to warp or bubble.  The cracking is likely related to the heating and cooling cycles and fairly thick plate combined with the small holes leading to stress concentrations.

Is the plate air cooled via the holes?


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## Skippydo (Nov 19, 2010)

Wil:
First time on this post WOW, still a lot of problems out there with the burnpot, I see.
This is my third year with the PF100, and luckly, no problem with the burn pot.  For
whatever it is worth, I start the unit up on Auto, then switch to Manual and run on manual
till next cleaning.  Have mentioned this in the IBURNPellets.com.

Will keep checking this site out....


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## Bill Bennion (Nov 19, 2010)

Just finished installing new burn pot on PB 105 with 15 fin igniter. High temp SS on burn surface. We will see if this solves the distorted surface issue! I will be keeping Harman updated as heating season progresses.

Posted this this week and am disapointed to hear that Wil is still having the problems


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## stan240 (Nov 28, 2010)

On my 4th season with the PF-100, have the burnpot problem now. Does anybody have a cheap place to order them? Replaced my auger motor 2 seasons ago and locate dealer hosed me for $360. Also should I replace the Igniter  now that it is out?


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## Bill Bennion (Nov 28, 2010)

stan240 said:
			
		

> On my 4th season with the PF-100, have the burnpot problem now. Does anybody have a cheap place to order them? Replaced my auger motor 2 seasons ago and locate dealer hosed me for $360. Also should I replace the Igniter  now that it is out?


The burn pot should be covered under the 6 year gold warranty.


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## Bill Bennion (Nov 28, 2010)

wil said:
			
		

> slowzuki said:
> 
> 
> 
> ...



Wil,  Have you heard anything new from Harman?  I have not seen any problems yet with my ss burn pot, but given your results I expect to see problems develop in time.  Did you speek with Barry at Harman at all?


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## stan240 (Dec 1, 2010)

Great info, Have the burnpot issue took it off and cleaned up with a grinder with a wire wheel attached. Had a friend weld a piece of stainless steel to cover the whole. Drilled new holes in the patch and works great so far. new problem is the igniter. Is there a easy way to replace them. got the burnpot off without any problems just don't know how to get to the wires for the igniter. Have a picture of this patch if anyone ways to see it.


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## exoilburner (Dec 1, 2010)

stan240 said:
			
		

> Great info, Have the burnpot issue took it off and cleaned up with a grinder with a wire wheel attached. Had a friend weld a piece of stainless steel to cover the whole. Drilled new holes in the patch and works great so far. new problem is the igniter. Is there a easy way to replace them. got the burnpot off without any problems just don't know how to get to the wires for the igniter. Have a picture of this patch if anyone ways to see it.



stan,
Really glad you are trying this.  How big was the new stainless steel patch you put in your burn pot.  Did you weld it so it was flush with the surface of the hole plate?  Were any holes welded over?  

I was thinking that this may be the only option owners have if Harmon does not get with the program.  It doesn't seem like it would be a difficult job for someone with a little welding experience.  And it would be possible to try a piece of the hi-temp steel that "*wil*" was talking about in an earlier post.

The igniter is pretty easy to remove.  You may need to cut the tie-wraps on the igniter wires.  They are located under the sheet-metal cover that is screwed to the bottom of the pellet hopper.  Then you can pull the igniter and wires out thru the burn-pot cleanout hole.  Pull the wires out until you can see the wire connectors and disconnect them.  The igniter mounting screws are located above the burnpot cleanout cover screws.  Be sure to remember the orientation of the igniter mounting bracket; it can be installed reversed.  AND PULL THE NEW IGNITER WIRES BACK INTO THE AREA UNDER THE COVER.  Otherwise the connectors may melt.


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## stan240 (Dec 3, 2010)

the patch is about 2 inches square, its pretty flush. We drilled new hole because some were covered. I have a pic but it to big for this site, don't know how to resize it. My 2c on this is, most are probably scraping the burnpot when it is hot and the metal it much softer. I think that spot gets the extra pressure because its much easlier to reach. Orderd new pot and igniter but will probably wait until summer to install. This is my 5th season on this unit and my heat bills went down by2/3 vs propane forced air. we average about ten tons per and we just love the nice warm heat. House is 2700 sq and two story with vaulted ceilings and lots of windows. Payback on this unit was 1.5 years.


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## exoilburner (Dec 3, 2010)

stan240 said:
			
		

> the patch is about 2 inches square, its pretty flush. We drilled new hole because some were covered. I have a pic but it to big for this site, don't know how to resize it. My 2c on this is, most are probably scraping the burnpot when it is hot and the metal it much softer. I think that spot gets the extra pressure because its much easlier to reach. Orderd new pot and igniter but will probably wait until summer to install. This is my 5th season on this unit and my heat bills went down by2/3 vs propane forced air. we average about ten tons per and we just love the nice warm heat. House is 2700 sq and two story with vaulted ceilings and lots of windows. Payback on this unit was 1.5 years.



If you look at the post with the 4 pictures on the first page of this thread they show the deterioration of the metal on the underside of the plate.  It looks like metal is flaking off in the bad spot from the inside of the burn-pot.  So it is getting thinner and weakening.


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## Dbbitt (Dec 23, 2010)

maybe they should cast that surface of the pot like the lid that is on top of the pot or maybe make a ceramic part replacing the welded in surface of the burn pot.. the ceramic wouldnt be changed by heat and if it is smooth would be easy to clean. Maybe they could make the surface a replacable part instead of the whole burn pot thus reducing the costs and end user replacable.


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## Dbbitt (Dec 27, 2010)

I just called the dealer to send me a new burn pot. i was cleaning my unit and the bubble was in the pot i replaced last year. I asked him to call harman and see what the send.


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## exoilburner (Dec 27, 2010)

Dbbitt said:
			
		

> I just called the dealer to send me a new burn pot. i was cleaning my unit and the bubble was in the pot i replaced last year. I asked him to call harman and see what the send.



Dbbitt, thanks for the posts.  I am kind of anxious to see how *stan240's* welded patch fix works.  If it lasts and does not affect furnace operation it might be a fairly simple permanent fix.  Would be able to experiment with some different types of plate too.


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## yargyamel (Dec 29, 2010)

My PF100 started operating for the winter 2006/2007. My burnpot has been replaced once and is cracked again. I have had some issues related to the furnace running and several components have been replaced but they did not replace the burnpot a second time. I need to check my warranty again. I know it says 5 years and I don't recall the three year limit on parts the dealer mentioned or what is written in the newer manuals. I use about 8 tons per winter to heat about 3500 sf, replacing 1000 gallons of oil. When the furnace runs good it is great but yesterday the house was not staying up to temperature and so I turned the furnace control to off and turned the oil burner back on. This morning the fire was still burning at a minimum flame in the burnpot so something is not right. I get the impression the manufacturer is not making things right, because if they were the dealer would be trying to make it right. As much as I like the unit sometimes I wonder if I got a lemon or it is not ready for prime time. My 20 year old oil burner starts every time but I hate using oil, especially foreign oil !


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## stan240 (Jan 12, 2011)

My patch only lasted 1 month, but the thought was there. Replaced with new burnpot and igniter. New problem auger not feeding enough pellets. Will empty the hamper and hope its something simple.


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## exoilburner (Jan 12, 2011)

stan240 said:
			
		

> My patch only lasted 1 month, but the thought was there. Replaced with new burnpot and igniter. New problem auger not feeding enough pellets. Will empty the hamper and hope its something simple.



stan:  Did you cut out the bad area of the burnpot plate and weld in a new piece of plate or weld a patch over the bad area of the plate?
What type of weld did you use, arc, gas ?????  Would be nice to know in case someone wants to try it again with a different process.  

When mine goes out of warranty and I have to buy a new pot I'm going to take the old one to a welder and try this.


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## stan240 (Jan 12, 2011)

We just patched over the old area. New patch failed in the in the same spot. I saved the old burnpot and going to my friend who welds for a living and have him look at it and make a better repair and use it for a backup. Have some pics will try and post.


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## stan240 (Jan 12, 2011)

Here are the pics. One is the burnpot repaired, the other one is the patch that failed and lastly what was keeping the auger from feeding. Try the obvious with your auger problems, emptied the hooper and there it was. When they ship the pellets on top of the pallet is a thick piece of cardboard. My thoughts are that when they were loaded on my trailer the forklift pushed the cardboard into the bag. The pic shows a small piece of the bag and the cardboard. I just usually tape bags when I get home. The forks just pushed all that stuff farther into the bag.


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## exoilburner (Jan 13, 2011)

Thanks for the good updates and the pictures.  The pictures really add a lot.


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## Pellet_Dog (Jan 14, 2011)

This problem needs to be attacked just like fixing rust on a car.  Cut all the bad metal out and weld a new piece in or the cancer will just come back and spread.


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## Skippydo (Jan 14, 2011)

Interesting what happened today while cleaning the PF100.  You guys might alrerady do this,
but this is the first time for me.  I cleaned the burn pot, cleaned underneath, and then I took
the end of the screwdriver which I use to scrape the scale off with, and taped the top of the
burn pot.  I cannot believe the amount of soot that fell from underneath the burn pot.
I just said "WOW".  I was truly amazed.  
And I did notice a hotter burn. 

And then, I had to replace my water holding tank.  The bladder went in it.  
Don't know if you use those new connections where you just push them together.
Can take a variety of pipe, copper to plastic, etc. no more heating and soldering.  In a split
second the connection can be made...


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## stan240 (Jan 14, 2011)

I think you are right. I will have my friend just make a whole new top plate and use some better steel. Plus he will probably do it for a case of keystone. Great forum btw.


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