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Esp temperature probe on Harman....how can you tell if going bad?

Post in 'The Pellet Mill - Pellet and Multifuel Stoves' started by Val, Nov 8, 2012.

  1. Val

    Val New Member

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    I have a 2006 Harman accentra that has been run every season...maybe I have gone through 15 tons of pellets in 7 years. when I started using the stove this season, I notice that my temperature setting seems off. when I set the stove control to "room temperature" of 70..the room only makes it to about 62 degrees. If i want a 75 degree room, i have to set the control to 80. It seems that the temperature control is 5 to 8 degrees off. In the past, this control was right on the money..within a degree or two.

    Could it be that the probe end is "dirty" and needs cleaning? or is this a sign that the sensing bulb is failing? So what do i replace...just the sensing bulb and wires? or the plug too at the back of the stove?
    The sensing bulb has been located on the wall behind the stove in the same spot.

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  2. Harman Lover 007

    Harman Lover 007 Minister of Fire

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    Just to be clear for others who may be reading this, the ESP and the room temp sensing probe are two different things.
    Val, when was the last time you cleaned the ESP? As you probably know it senses the exhaust temperature and probably isn't the culprit but I wouldn't rule it completely out. Check the connections on the room temp probe and make sure they clean and tight. If you haven't cleaned the exhaust path and the ESP in a while I would definitely do that as well . Remember the ESP is very sensitive. Be very gentle with it.
  3. Val

    Val New Member

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    I bet I should use window cleaner to clean it? or maybe isopropyl alcohol? It ican get dusty in the room where the pellet stove is. Maybe this has an effect on the sensing bulb.
  4. Harman Lover 007

    Harman Lover 007 Minister of Fire

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    Do you clean your stove yourself? Do you know where the ESP is located?
  5. floyd4th

    floyd4th New Member

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    i just went through the same thing last week with my p68. when my ESP probe failed my stove went to low setting then never refired. this could get a little tricky, being that it could be a combination of both. if the esp probe is going bad it could be saying that the stove is hotter than it actually is. which would result in the stove not coming on until the room is actually colder than the set temp. on the other hand i have read on a few other posts the the room temp probe is not always accurate. it can be off a few degrees from another thermometer setting right next to it. either way both are not that expensive to change i paid $42 for the esp probe and i dont think the room sensor is that much either. Also if the room sensor is bad look into putting a wall thermostat in the system. there is also a good forum here that will tell you how to do that.
  6. floyd4th

    floyd4th New Member

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    BTW my P68 is also a 2006. these parts unfortunetly don't last forever. a little more info if you do replace the Esp probe there were two different part numbers available for my stove. one has red leads and the other has black.depending on the year of your stove it may have one or the other (i think they changed them around '06) i believe mine was the black. if they dont have the correct esp probe both will work you just have to change the #5 dip switch on the back of the control board to the opposite position.
  7. P38X2

    P38X2 Minister of Fire

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    I think the room temp sensor is around $25.

    Seeing you have it located behind the stove perhaps pellet dust has made its way inside? Maybe try vacuuming it. Electronic cleaner spray may work too but not sure if its safe. Definitely power down the stove if yer gonna go that route.
  8. Lousyweather

    Lousyweather Guest

    only sure way to tell.....have your helpful, smart, good-looking Harman tech come out and put his DDM on it....

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