Thanks for the info and pictures Will. Can't tell for sure but will this burnpot support the older igniter that mounted in the burnpot? I am looking forward for your updates.

The burnpot that is installed in my boiler doesn't have the holes or knockouts needed for mounting the finned igniter, maybe Harman will do this on future burnpots. If they don't, it wouldn't be hard to do.

Thanks again Wil, maybe something to look forward to.

I just finished my weekly cleaning of my boiler this morning,it has been a couple months now since the newly designed burnpot was installed. This is the longest period of time without the bubble starting to form since the boiler was installed nearly 6 years ago, this burnpot hasn't developed any bubble, it looks the same as when it was installed. I believe that it's a combination of two things, the draft adjustment that was adjusted so the combustion blower is running at maximum RPM when a fire is in the burnpot plus the design of the new burnpot. I'm thinking that for those that own the pf100's or the pb105's having "the burnpot bubble issue", talk to your dealer, asking if these burnpots are available, hopefully under the warranty.

Three month update: Last friday while cleaning my boiler I noticed hair-line cracks, no bubble, on the surface of the newly designed burnpot so this burnpot was not the answer to the burnpot issues. Today, I called Harman, asking what the plan was now. The person I talked to confirmed that the engineers at Harman are still working on a solution to the burnpot issue, explaining to me how important it is to keep the holes in the burnpot surface clean, basicly trying to pass the buck to me not keeping the holes clean. I mentioned to him this wasn't the case because I clean the burnpot weekly including the holes. When I asked as to what material the burnpot was made he told me stainless steel, I asked what grade, he didn't know. I did mention to him that to my knowledge, no grade of stainless steel has a heat resistant value high enough to withstand the heat created in the combustion area of these boilers, mentioning maybe to try using alloy 600 for the burning surface of the burnpot. His response was that it might be cost prohibited to do so to which I responded, if the metal alloy that is used for the burning surface of these burnpots doesn't have a heat resistant value higher than the temps created in the combustion area, the burnpots are going to continue to fail.

Thanks for the update Wil. One would think that with the air moving up thru the burnpot it would help cool the SS metal. I would think that is why Harman is concerned about keeping the holes clear of ash etc. It is impossible to keep the holes clear though, while the burning pellets move over the top of the burnpot. What if this process is acting more like a bellows, causing the stainless steel to become super heated much like a black smith heating metal to soften it? I know the pro burnpot has been around for quite awhile so maybe I am way off base, I don't know. Obviously making the stainless thicker didn't resolve the issue so maybe a higher Ph is the answer Wil. What about a cast iron burnpot surface plate? Now that the igniter is no longer inside the burnpot, a cast iron plate of a decent thickness could be welded to the stainless steel assembly. Cast iron has always held up nicely in stoves and boilers forever. Of course, what do I know and even though Harman has been supplying replacement burnpots, I am getting tired of changing them out Thanks again for the update Wil.

wil wrote:
Last week I got a call from my dealer telling me he received another burnpot from Harman, they want the burnpot with the cracks returned for inspection. This burnpot appears to be the same as the one that will be sent back, the only difference I can see is the sides of this burnpot are a thicker metal. I did ask if the alloy used for the burning surface was different, my dealer said he didn't know but he is supposed to find out for me.

Interesting news Wil. I also have the same problem as you with the new ignition system and the bubble issue. The bubble appears to be a little further down inside the burnpot than before but still within the area of the holes.
I know from previous posts that you burn your PB105 all year long. I can't do that so I bought a urethane electric HW tank so I didn't need to use my oiler for the summer months. I plumbed the HWT in after the PB105 so that in the summer (6 months) the domestic coil warms the cold water to room temp before it hits the HWT and in the late fall, winter and early spring months I shut the electric off and use it as a storage tank. I don't get the temp fluations anymore either! So my summer electric bill went up $30 bucks a month which totals to $180 a year which is a ton less than the oiler would have cost. I only mention this cause you might appreciate not having to fill the hopper in the summer plus the wear and tear and cleaning to the boiler not to mention that pellets are typically $5 bucks a bag which adds up. Just a thought.

John