Harmon P68 got me stumped and I know these stoves well !! help

[Doug Doty]

Needing advice on P68, Normally this stove will run us out of the house if we crank it up and ask it to, this is our 4th season with it now and it is normally a horse, that will make 2x the heat we actually need if asked. I always use somerset hardwood pellets, but now this season we are on bag #3 and it is seeming wacky. I always default to cleaning so I done a super detailed couple hour cleaning last week but it still will not build a big fire regardless of setting. Seems to not respond to temp settings at all. The real problem is low output. Any ideas ?? It is clean as a whistle all the way through and out. I cant get it to build a fire that will reach up and out of the top of the fire pot. ( just barely maybe) Talked to my dealer, lots of questions and answers, " he is great " !! I decided with his thoughts on probability that I was willing to get a new esp probe and a new board to have and try as spare parts. When I got home I ohm'd my probe and it was in the 1000 to 1100 ohms spec, new probe matched. So I cleaned mine and reinstalled it. Decided to install the new board and now a new problem. With the new board it once again starts up great but as soon the fire lights it throws a 2 blink status code which is air flow problem, combustion air specifically. My blower is whistle clean, spinning up to speed and it is performing normally based on smoke exhaust flow just prior to ignition," I always watch the exhaust as it light off. Like I said it lights off and throws the 2 blink status code and that triggers the lock out of the auger as a built in protection and it slowly burns itself out. I put the old board back in and it runs as before but with the exact same problems. I am baffled and am actually considering I got a bad board and a bad new board as well. Does anyone have any thoughts. I am stuck setting here with my room temperature holding around 72 and the stove set for wide open and it is burning such a small fire it is contained down inside the burn pot to just slightly above and wont further warm a 16x20 room that it normally could seriously run you out of. If anyone has questions I got 10 hours in on this and I got answers. I tried to be complete here but I am sure there could be questions to help sort it out. pic is of my fire burning wide open.

 

[miteclipse]

Is your vent pipe clean? Make sure your feed and igniter cover are tight. Did you dollar bill test your door gaskets? Check hopper lid as well. Turn the latch nut a few times as that becomes loose over time. Lastly, make sure the air intake flapper moves freely.

 

[Washed-Up]

Sounds like the hopper lid as stated above, or a vacuum leak...keep us posted.

 

[Ssyko]

Going by your pic, all the fireflies tell my the vent and combustion motor seam to be good. Vac hose or switch might be an issue. Is there to much air moving? I dont work on to many harmans so im not proficient on their components and systems.

 

[bogieb]

Do you run an OAK? I would make sure nothing got sucked into that pipe (or into the air port at the back of the stove). I had a small piece of plastic wrap get sucked up somehow and it got stuck on the flapper - drove me nuts trying to figure it out.

Also, I know you said you cleaned, but sometimes we don't think to check to make sure ash below the firepot hasn't set up in front of the port for the airflow (you have to stick your fingers way back there. It can build up enough to restrict air flow even if all the ash in front (by the igniter) has been cleaned out.

 

[bogieb]

For the original problem (before the #2 light came on), check to make sure your room temp probe is plugged in snuggly in the back of the stove. If it gets disconnected, even just loose so it "looks" plugged in, the stove will go into idle mode because it doesn't know what it is supposed to do. Also check to make sure the room temp probe isn't touching the stove - that will wack out how it runs too.

 

[rickwai]

Did you empty your hopper and reach down in slide plate area to be sure there is not a object partly blocking pellet flow? like a ink pen or random object. Also did you try running in stove temp mode with all 3 dials wide open? That would take room sensing probe out of the equation?

 

[linc1216]

I had the same problem after having a chimney sweep of my vent pipes. I think the worker disconnected my ESP probe plug, because I got 4 blinks on the panel board. So, what I did was put my stove in constant burn with the feed rate still at 4 and my Harman is working GREAT! Now, I'm waiting on the chimney worker to come back and make sure my probe is where its supposed to be.