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.

That would be my guess also but I would first try cleaning it if you haven't already. I purchased a spare on ebay.

www.ebay.com/itm/1-00-00744-esp-replacem...;hash=item1c301fdcfd

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.

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.

Did you unplug the 9 wire plug from the controller and measure the voltage at the pins of the control board where the red and white wires connect? If no voltage can be measured on the board when the stove is powered on, my guess is that the controller is toast.

The combustion motor has to run to close the contacts on the vac switch. When these contacts close, the auger and igniter both are powered, so, you need to determine why the combustion motor won't run. It could be that its not getting power from the controller or its getting the proper voltage and the motor is bad. A voltmeter and knowing how to use it (not difficult)would be very helpful at this point.

Have you tried to unplug the stove from the outlet, maybe this will reset it. If the combustion blower doesn't run, even though the lights for the auger and igniter are on, they are not getting any power to be on. The combustion motor has to run to close the vac switch which in turn will power the igniter and auger. Also,when the stove is not powered, make sure the combustion blower motor turns freely when turned by hand.

For those that are in need of the Harman control board repair, less expensive than a new control board


www.ebay.com/itm/Harman-Pellet-Stove-Con...;hash=item2c68956561

I'm not sure if you have an aqustate problem, the reason, the fire has to be big enough to satisfy the high temp setting of the boiler. I recall back when I first installed my boiler, I had the feed rate setting on the lower settings, the boiler would never reach the high temp setting of the boiler, basicly would run all the time because it didn't have a fire large enough. I found and it is MHO the feed rate needs to be adjusted up to the point that pellets are not overflowing into the ash pan. It is quite possible that this adjustment has to be made whenever you change brands of pellets. I've had to adjust to the maximum when longer pellets are being used, as low as #4 with shorter pellets. It's a trial and error with the feed adjustment, like I've mentioned, adjust so as no unburnt pellets going into the ash pan. The amount of pellets that are fed into the burnpot prior to ignition may result in pellets overflowing into the ash pan at a higher setting of the feed. For example if the burnpot fills 3/4 full of pellets before ignition, when it ignites and pellets start feeding, it is quite possible to overflow pellets into the ash pan. If you adjust the feed rate to compensate, after the initial fill of pellets are burned, it's quite possible that not enough pellets will be fed creating a small fire which won't allow the boiler to reach maximum temp setting.

1stPB105 wrote:
I totally agree with you but....... a word of caution to you. A couple months ago I had 3 people from Harman along with my dealer come to inspect my boiler because of the burnpot bubble issue which I've had for the past 5+ years.One of the Harman reps adjusted the draft screw on the controller so that it would always run at full speed. It had been adjusted per Harman spec but he felt that not enough air was passing through the burnpot which was causing the bubble to form in the burnpot, as of right now I think he is correct,so, be careful restricting the air going through the burnpot .

The dip switch settings using the finned ignition are: #1 off, #2 off, #3 off, off position is down. I don't remember but I think when I had the finned ignition I set the swithes #1 off, #2 on, #3 off, less pellets in burnpot for quicker ignition. When in auto the boiler should come up to the max temp setting and shut down. Set the feed rate to #5 and it should shut down when the max temp setting is reached. IMHO, dip switches 1,2,3 in the on position feed to many pellets into the burnpot for good ignition.

First, congrats on the purchase of the pb105. My boiler is one of the first produced also,12/06, been installed nearly 6 years now. Even though I, along with many others, have had the burnpot bubble issue, I would certainly buy the boiler again. The new burnpot that was installed in my boiler 3 weeks ago shows promise that the bubble issue could be resolved, only time will tell. I have my pellet boiler piped in parallel with the oil boiler so as to supply DHW usage, I do not use the OAT sensor because it didn't workout for my DHW usage. IMHO, I don't think your issue with your boiler not heating above 140 degrees was the ESP, I recommend setting the feed rate to #5, adjust the minimum water temp pot setting to 160 degrees, high setting to 180 degrees. This will take some time because the actual pot adjustments will not match the actual water temps. When the feed rate is set at lower set points, it is possible that the boiler will never reach the high operating setting, higher settings of the feed rate adjustment will produce a larger fire which will allow the boiler to reach operating temps faster. I found that pellet usage is less when using a higher feed rate. You have mentioned that you have the newest control board, what part number is on this board? you also mention that you have the new igniter, is it the 15 fin igniter or is it the pressure ignition system? I ask because depending upon what igniter and control board determines where the dip switches are positioned.

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.

The photos are of the newly designed burnpot for the pb105 and pf100 which Harman has been testing for the past 2 months in an effort to resolve the burnpot bubble issue. I have it installed, time will tell. My dealer told me that this will be the burnpot used in all new central heating units manufactured from now on.The burning surface is 3/16 stainless plus notice the fact that the burning surface is not solid welded to the sides to allow for expansion.

heiligkuh.com/bbandp/product_info.php/pr...43c3918c2012736967e6

Another option.

I contacted my dealer last week looking for the new burnpot which still hasn't come. I was told that this new burnpot has been tested at Harman for the past couple months and it is a two piece type to allow for expansion to(maybe) stop the bubble from forming. Adjusting the control for maximum RPM of the combustion blower made sense for my boiler installation, the boiler exhausts into a masonary chimmney which has a natural draft, the reason the controller was adjusted to what the owners manual specs out.IMHO, I believe that this bubble issue is bigger than what Harman cares to admit, it's happened on several PB 105's and pf 100's, the reason for this new burnpot design, in fact, I was told that this new pot design will be on all the new central heating units. As soon as I receive it I will post some photos prior to installing it.

UPDATE: It has been nearly 3 months since the new designed burnpot was installed in my boiler. To date, this burnpot looks the same as when it was installed, no bubble issue at all. Prior to this burnpot, any that were replaced,after 2 weeks a small bubble could be seen forming. If you have a pb105 or a pf100 with the burnpot bubble issue, if you have the pressure ignition, talk to you're dealer about this burnpot. If you have the finned ignition, talk to you're dealer, telling them about the fix for the bubble issue, maybe changing to the pressure ignition with this burnpot, do it now before the warranty expires.

If you are handy at soldering or know someone who is these will repair the controller. I bought a set for repairs when needed on my boiler.

www.ebay.com/itm/Harman-Coal-Pellet-Stov...;hash=item1c2055bd61

VT_Bubba wrote:
My dealer along with myself installed the pressure ignition system in my boiler. This was done under the warranty in a effort to stop the burnpot bubble issue, didn't help. The retrofit was a little more involved on my boiler because my boiler was one of the first manufactured by Harman,some changes in design to later boilers would make the installation easier.

A boiler with the finned ignition, the igniter is located within the burnpot. The pressure ignition, the igniter is located outside the burnpot with a air pump that forces the hot air into the burnpot. The link below shows the igniter and air pump.

www.tempco.com/Tubular%20Process/In-Line%20Heaters/HAC.htm

Did the burnpots that were replaced look like the newest design? Post # 13

www.hearth.com/econtent/index.php/forums/viewthread/84645/