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Harman Pellet Stove problems....

Post in 'The Pellet Mill - Pellet and Multifuel Stoves' started by tricky, Dec 6, 2011.

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  1. tricky

    tricky New Member

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    Hi! I found this site while I was searching for some answers to my problems with my pellet stove, and I was hoping to possibly find someone who might be able to help me.
    It is a harman pellet pro II from 1993, which we just bought a few months ago. When we first used it, it worked really really well. But now the stove thermostat seems to be stuck in 2, even though we have it set at 7 (the highest). We have to open the feed rate way up in order to get any heat. The stove feeds pellets but only a little bit, and the pellets don't seem to push forward. Lots and lots of ashes accumulate at the front of the burn pot, but don't really push forward, at least not like it did a few weeks ago. The fire is burning deep in the throat of the ash pot. All of the motors seems to work and there aren't any new sounds. We have tried different pellets, and also cleaning it out several times. We have taken things apart and there doesn't seem to be any jams and the pusher arm is freely able to move and the auger turns. The probe seems to be working because when the stove runs out of pellets and cools down all of the motors will eventually shut off, and the stove shuts down. We have tried setting it up to a thermostat but that doesn't seem to make any difference in the stoves performance. When we change the feed rate the knob doesn't have the same resistance that it used to when it was working properly. It used to meet a bit of resistance then slack up again as it was turned. Now it just gradually tightens up. It's starting to get cold and any suggestions would be very much appreciated! Thanks so much for reading!

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  2. 76brian

    76brian Feeling the Heat

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    Are you SURE the burn pot is clean? All the little holes need to allow air to flow, you might need to scrape the burn pot better. If it's been a while between cleanings you need to REALLY put some elbow grease into it and scrape it good. A mirror and flashlight will help to see if all the holes are clear. An old drill bit helps to unclog them too.

    Hows your door gasket look?
  3. lecomte38

    lecomte38 Feeling the Heat

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    set the feed rate at the maximum and regulate the feed rate with thermoo setting or manual.
  4. timjk69

    timjk69 Member

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    Can you tell if the auger motor is running well in test mode? I had a similar problem, along with not feeding enough pellets to get good ignition. The auger gear box was bound up along with a bad bearing on the motor. It was running at about 1 rpm.
  5. Harman Lover 007

    Harman Lover 007 Minister of Fire

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    Sounds like bad pots on the control board to me.
  6. ironpony

    ironpony Minister of Fire

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    Can't be the stove
    after all
    it is a
    HARMAN
  7. tricky

    tricky New Member

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    Hi, Thanks everybody for your ideas. My husband did clean the burnpot with his drillbit but there still seems to be a problem. We were told if the motherboard or enhancement card wasn't working properly that it wouldn't work at all. A tech. at a shop nearby told us they thought it might be the probe after all, and that it sounds like the stove is permanently stuck in start up. We have a probe on order...fingerscrossed!! Thanks everyone for your time and suggestions!!!
  8. tricky

    tricky New Member

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    Well...we got the probe, and it wasn't the problem. Someone mentioned bad spots on the circuit board....would the circuit board still work at all if it had bad spots on it? The seals seem okay, the fire has a tall flame that burns well. It just seems like it doesnt push enough pellets forward. I am so confused!
  9. Harman Lover 007

    Harman Lover 007 Minister of Fire

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    That would be me and I said bad pots, not bad spots meaning the CB has one or more dirty or bad potentiometers. This was a big problem with the early to mid 90's Harmans. I'm not 100% sure of your CB but if it is like most of the stoves of that vintage, the adjustable dials such as feed rate, room/stove temp and the regular temp knob are all potentiometers that get dirty and full of dust and fail. Do a search for replacing pots on Harman CB. Folks have done it here. They can be had on EBay for less than $10.
  10. wil lanfear

    wil lanfear Feeling the Heat

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    If your comfortable using a soldering iron or know someone who is, these maybe the correct pots to make repairs to the controller. I would contact the seller to insure these are the correct ones for your model stove.

    http://www.ebay.com/itm/3-Harman-Pe...838?pt=LH_DefaultDomain_0&hash=item27c192574e
  11. tricky

    tricky New Member

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    Sorry about mis-reading your message, Thanks so much to you both for taking the time to respond so quickly! I have contacted the person on Ebay selling the pots to see if he thinks if they will work in my stove. *crosses fingers* I have a neighbour who builds model planes and solders control boards and such, I think he might be about to help with the installing of them. Thanks again so much- Happy New Year.
  12. MCPO

    MCPO Minister of Fire

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    Ok, This is a re-post of mine. I`ve already been thru the changing of the pots on my Harman.

    Yes, on Ebay. They were $16. for both of them. Soldering the new ones in was simple enough.
    The hard part was removing the old ones without ruining the whole circuit board.
    You need a solder sucker for sure otherwise you can`t get the old pots out without a great deal of difficulty. The 2 small tabs are bent over and soldered in and the other 2 are larger and snap in. The solder runs in and ends up on both sides of the board.
    You also need to swap out the shafts since the old knobs fit on half round ends and not on the newer full rounded ends. Of course that might depend on which stove and how old it is that you have.

    Added later: Thinking about this more , the rounded shafts allow a knob to be positioned anywhere in relation to the feed rate numbers on the stove but the 1/2 round shafts fit only in one position .
    You might find your feed rate setting slightly different when the new pots are changed.
  13. tricky

    tricky New Member

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    Thanks Gio for your advice. I heard from the person on ebay selling the pots. He told me it sounded like a control board issue, and how to test the pots, and if it isn't them (using an ohmeter or something?) than it is the *dreaded* control board. I have found one for sale for over 360$!! I hope that isn't the case!! My husband thinks the neighbour has the ohmeter and knows how to use it!
  14. MCPO

    MCPO Minister of Fire

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  15. tricky

    tricky New Member

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    My husband noticed a small black (burnt-looking)spot on the control board. If part of it was damaged would it still work (poorly) or would it not turn on all together? Thanks Gio for the link!
  16. MCPO

    MCPO Minister of Fire

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    If it is a burnt spot on the board then it`s likely the problem. That would usually means the board needs to be replaced unless you know a good electronics person who might be able to fix the old board.
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