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Harman p35i overfeed on combustion problem

Post in 'The Pellet Mill - Pellet and Multifuel Stoves' started by Burning up, Dec 28, 2011.

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  1. Burning up

    Burning up New Member

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    We purchased a Harman p35i last December and burned most of last year with no problems. At the end of last year we noticed that the burn pot seemed to overfill with pellets before igniting and then the flame was not as high. This year the problem got worse and the pot would overfeed, it would try to ignite and unburned pellets (or partially burned pellets) would drop into the ash tray. One of the problems is that it does not do this consistently. Sometimes the fire will start and play catch up before any unburned pellets fall into the ash tray. We have had three service calls to the house for the problem for a total of 8 hours of techs looking at the problem. So far they have replaced the combustion blower, the room temperature sensor, the burn plate gaskets and the esp. The stove is presently working but upon ignition we are still having the same problem (just not quite as bad) and the flame does not seem to be as high as usual. There seems to be more ash as well but I'm not 100% sure about that. We were told that it was a cleaning issue at first, but the tech found the unit to be clean; Harman says its an airflow problem but they can't seem to find anything wrong. Its very frustrating to have invested over $3000 in a stove and within a year the stove is not working properly and they can't seem to find out what the problem with it is.

    Has anyone else had this issue with the Harman p35i? Does anyone have any suggestions?

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  2. ironpony

    ironpony Minister of Fire

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    generally from my own experience and reading others on here
    usually the ESP is bad or dirty
    stove is dirty
    exhaust is partially plugged

    seems you covered those areas already
  3. kinsmanstoves

    kinsmanstoves Minister of Fire

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    Have your dealer figure it out. could be an air leak, dip switch settings, sticky flapper in the intake at the feeder, or a faulty feed rheostat. Get the dealer involved, use the warranty, you paid for it in the price of the stove.

    Eric
    Murph likes this.
  4. Burning up

    Burning up New Member

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    The Dealer (he's more like a wheeler, dealer) that we bought the stove from was useless. When I first called in it they were telling me it was a cleaning issue and could not come out for a month and a half. After six phone calls and insisting upon talking with the owner, they finally agreed to send someone out within a week. The "service tech" (and I use the reference loosely) came in carrying a shop vacuum still thinking it was a cleaning issue. After being there for more than two hours (because of course the customer was right and the unit was clean) during which he asked me for a paper clip so he could hot wire the combustion blower and stick it into an electrical outlet and bringing in his socket set and dumping it all over the floor so he could find the right socket;replacing the combustion blower and room sensor probe; failing to check the draft on the stove or hook up Harman's diagnostic reader, they charged us $250 with the explanation that Harman will only give them $55 for a service call on warranty items and they have to charge the customer for the rest. Needless to say I placed several unreturned phone calls to the owner and then stopped payment on the check. That prompted the owner's wife to respond saying it was a mix up and she doesn't know why the service tech did that but "you can't blame a guy for trying to make money"!!! So I refuse to deal the the "Dealer" on this. I did approach another dealer in the State who was courteous, professional and didn't charge a dime.
  5. smwilliamson

    smwilliamson Minister of Fire

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    There are several things to consider. First, what pellets are you burning? I'm NOT saying that it is the pellets but need to set a bench mark. The feed rate on the stove set at a range of 3-4 assumes a pellets that is compressed to a density of about 40lbs per cubic foot. I need to know you pellets and the feed rate you are using. Secondly, I need to know how tall your liner is within the chimney and its diameter. Talk with me about the glass. Does it get dirty quickly? Does it get dirty in one spot quicker than another area? DO you use room temp or stove temp? Where is your room thermostat located? Are you using an air kit? Is the damper flap for the air intake obstructed or stuck closed? Is the air intake access plate snug? Is the igniter carriage in backwards? Are the ash drawer latches closed?

    All of your problems are connected to air flow issue. A draft test is required to set another benchmark. Did you get the trim kit with your purchase? Are the bolt that hold your trim kit on flattening out the door seal or did the door seal become compromised during the install? Did the door latch get installed backwards? Of course being in front of the stove one should quickly be able to look over this list of common installation mistakes.

    Lastly, one should make sure that the DIP switch setting on the control board are set for your stove and ESP.
  6. Cincinnati Kid

    Cincinnati Kid Feeling the Heat

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    Could it be the ignitor itself that is the problem?
  7. rickwai

    rickwai Feeling the Heat

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    Have any of you seen the igniter cradle assembled backwards from the factory? We had a install this fall that we put in and would not lite. It was pulling proper watts had good pellets, but would not lite. We messed w/ it for a long time before figuring out the igniter was assembled wrong. We switched igniter around and all worked well.
  8. Burning up

    Burning up New Member

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    We believe that we have solved the issue. After searching the web and reading various posts online, we figured out it was the hopper gasket. The hopper gasket towards the front of the stove under the hinged door slowly pushes underneath and you no longer have a tight seal. It happened slowly over time and that is why the problem was not consistent. It is a poor design as far as I can see. The gasket merely has some sticky stuff on the back side which after being exposed to the heat over time wears away. We have secured the new gasket with high temp silicone and it appears to be staying securely in place, but time will tell. So those of you who have a Harman p35i need to watch that the hopper gasket stays in place. Hopefully we can save someone else from being as frustrated with the stove as we were.
    Lousyweather likes this.
  9. Renron

    Renron New Member

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    Firestarter,
    I joined this forum specifically to thank you for the gasket tip on the P35i. I was about to pull out my Igniter and test it with my MM, I was having the exact problems you had. Inconsistent lighting of the pellets, sometimes not lighting at all. Sometimes lighting after 6 minutes sometimes as long as 13. Once it even stopped the combustion blower and shut down due to a time out event! I repaired the hopper seal and "it works a treat". Side benefit the glass stays cleaner too! Not sure why?
    Settings; Igniter = Auto, Stove Temp = High, Temp setting = 85* Feed rate = 3-4
    Now I am loving my Harmon P35i again! We use it solely to heat our 4000 sq. ft. home, yes, we live in Ca. and not Nebraska, but where we live it drops to freezing every night in the winter.
    Thank you for taking the time to post a solution. This is the BEST use of the internet IMO.
    Thanks,
    Ron
  10. Burning up

    Burning up New Member

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    Eastern, CT
    You are more than welcome. If we can save people the frustration we have experienced, its well worth it. I think the most frustrating part was we had two different dealers come to our house for three service calls and numerous phone calls to Harman with out a solution. The glass is cleaner now because you were not getting a clean burn before. When the stove was not burning properly because of the gasket issue, there was much more creosote being produced. I'm sure the stove now lights in 2-3 minutes again and the flame is much stronger.
    Glad I could help,
    Warm again in CT
  11. Bizango1

    Bizango1 Member

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    Southern, MA
    Hello, I'm having this exact problem. I've had my stove for 3 years and this is the first time I've had any issues. I clean and service my stove and flue myself and I don't believe i'm having an air flow issue because the stove runs great once it is started. When I spoke to the technician on the phone I told him the stove took 12 to 13 minutes to start up and then it was explosive. I think the pellets are fine but I haven't tried a different type yet this year, I may do that. My question is can the igniter get old and not get as hot as it used to? The technician said they usually work or don't work at all. Clearly the igniter is work but i'm wondering if anyone knows if they get weaker over time. I hate to pay for a service call if I can just replace the igniter.

    Thanks all!
  12. fmsm

    fmsm Minister of Fire

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    I had the same issue, I figured mine out pretty fast as it was right after cleaning. It was caused by the seating of the right side plate. I reseated the plate and it was perfect
  13. Lousyweather

    Lousyweather Guest

    In my experience, no, either the igniter is good or bad. I havent ever seen one that works "sometimes", or weakly (although, just because I havent seen one doesnt mean it doesnt exist....like Sasquatch!)

    Usually, its ash sitting on the igniter. Sometimes though, it can be gaskets as well.....those are the hardest to diagnose
  14. hockeyfan

    hockeyfan Member

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    I had a 'sometimes' igniter, on a newly installed stove. Although (according to the dealer) the igniter itself checked out okay, the seating of the igniter wasn't correct, and thus sometimes it ignited on time and other times it fired up very late, if at all.

    After correcting the seating of the igniter, in a few years of use no further problem has occurred with the factory-installed igniter.
  15. Bizango1

    Bizango1 Member

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    Hi thanks for the response! could you explain the issue you had with the seating of the right side plate in more detail? As far as I can tell there is only one way to put this plate in that will allow the holes for the nut to line up? Perhaps I'm doing something wrong there.

    Thank you!
  16. Bizango1

    Bizango1 Member

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    Thanks I just took out the igniter and cleaned it, it didn't seam all that dirty. I'm going to give it a try again here in a few minutes. The pros show up on December 6th if I can't get it figured out. Perhaps it is a gasket issue, or it could still be a Sasquatch igniter!. At least I still have my Jotul 550 wood burner keeping the oil man at bay...

    Thanks for the response.
  17. Bizango1

    Bizango1 Member

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    Ok thank you for the response.
  18. fmsm

    fmsm Minister of Fire

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    I just got my new P35i and it appears they have changed the design slightly. On the one I had trouble with the could be a very little play in the plate about an eight of inch or so, that was enough to cause my issue. Do you have the new style with the slotted plates or do you need to line it up straight on?
  19. Bizango1

    Bizango1 Member

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    Ok Thank you, I have one from the first year they came out so they must be a bit different. My problem is fixed! I'm not exactly sure what did it but I did remove the ignitor and clean it, I also cleaned the exhaust gas probe and cleaned out some old ash that I didn't get when I cleaned it last year. If you remove the two side panels there is was quite a bit of ash down in the square alcoves. My ash vac cant get in there so I used a paint stirrer and pushed the ash to the back with is so I could get it with the vac.

    Also I do agree with an earlier post about the poor design of the hopper gasket. The first year I had the stove I had an issue with it and had to have it replaced. Now i'm very careful to make sure I don't close the lid until I make sure the gasket toward the front of the stove doesn't have any pellets on it.

    Thanks All!
    Lousyweather likes this.
  20. fmsm

    fmsm Minister of Fire

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    Those side panels lead to your exhaust and must be kept clean/unobstructed. I use a cone attachment that I have put a section of rubber gas line (about a foot) onto as a way of vacuuming the clean outs.
  21. Lousyweather

    Lousyweather Guest

    grats on fixing it!

    so, it was cleaning?
  22. Bizango1

    Bizango1 Member

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    Excellent idea! Thank you!
  23. Bizango1

    Bizango1 Member

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    Thanks Lousyweather Yes it looks that way. Perhaps a combination of a little ash in the igniter and a decent amount of ash down under the side panels that accumulated over three years. (I've always cleaned the stove but I never realized there was ash down in there - Rookie mistake I guess.) FMSM has a nice post above on how to clean out those inlets. Perhaps the exhaust airflow was restricted enough to cause the slow ignition. It seams to be firing up pretty well now between 4.5 and 6 minutes. Its no longer doing the mini explosion after 12 minutes so i'll keep my fingers crossed.

    Thanks again everyone. Cold here in Massachusetts...
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