Harman P68, Dancing pellts in burnpot

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I did not get much out of my adjustment either last fall when I finally hooked up a manometer and it was high but not near as much as your stove is showing.
 
If it is an older control board the potentiometer for the combustion blower did not have as much of an effect as the newer control boards, same as the distribution blower adjustment on the old boards, might as well have been a low / high switch than a variable adjustment. as far as the five extra holes that was harman's attempt at getting rid of carbon buildup, unfortunately it didn't really get rid of the carbon all the way just moved the area in which it formed in the pot and caused the augers tips to get burnt up especially when the stove ran on low often. normally i recommend people have the holes welded shut.
 
Too much draft. Get some aluminum tape and cover 1/3 of the intake and see if it helps slow the fire down a bit. If it helps, but the flame is still aggressive, cover it up to 50% and see how it goes. You want an active flame, but not an angry one. Do this at your own risk and keep an eye on the flame at idle and high fire to insure it doesn't get lazy. You can also check your exhaust during high fire to see if you are getting any smoke. Smoke = incomplete combustion or lazy flame. 50% of my intake has been covered for the last 2 years without any ill effects, your situation may vary.
 
Ok so I broke it down and gave it a full cleaning top to bottom. Then I let it fire up and took video . I know its pretty much overloaded because its only been fired for 10 mins or so but this really shows much better on how much air flow is being pushed around in there. lots of dancing and tossing

 
Facing the back of the stove above and to the right of the exhaust outlet if I'm reading the pictures correctly in the manual.
 
Im not sure what changed. After cleaning its not burning right at all now. large pile of hot ash but very little to almost no flame at all. and the flame looks to curl over the top and never comes up anymore. its burning almost double the pellets and giving half the heat. I cleaned out the fan behind the ash pan and cleared out all the ash inside the hole there that leads to the vent. is there some type of flue or baffle to control air flow? may have forced it open when pulling the ash out with the scraper?
I cleaned out the catch all under the burn pot in hopes that was it. and although very full it did not change anything after starting it back up.
 
Could be a failing or bad connection of the ESP? I had an ugly fire sucking up pellets awhile ago after changing pellet brands and did a complete cleaning and found the ESP to be more than twice its normal diameter from ash etc. Polished it up and the stove went back to its happy self.
 
might be, the ESP is where i was cleaning in that hole. that would change the way the air flows for the fire? because the fire curles down and forms liek a bubble. I just let it burn down to nothing and knocked all the coals to the bottom. then cycled out some pellets and even without a mountain of coals the fire still curls down like a bubble in the mouth of the burn pot and doesnt form "sharp tongues" anymore.
 
Reveiw the sticky on top of the page "How your Harman Works" The ESP controls feed and fans etc.
 
easy way to rule out the ESP? what if i switch to room temp instead of stove temp?

covering the intake not sure how to go about it correctly. there is a fan that faces the vent and into the back of the stove i assume leading to the burn pot feeding the holes. do i cover the fan? the stove side on the pipe itself?
 
easy way to rule out the ESP? what if i switch to room temp instead of stove temp?

covering the intake not sure how to go about it correctly. there is a fan that faces the vent and into the back of the stove i assume leading to the burn pot feeding the holes. do i cover the fan? the stove side on the pipe itself?

ESP is used all of the time you can't rule it in or out by turning a switch.
 
ESP is used all of the time you can't rule it in or out by turning a switch.


it in the manual it appears close to the front, would i be able to easily see it with a flash light and clean it out? is it recessed or dangling int he air? i jammed the scrapper in there pretty good i hope i didnt cut it right off :(
 
it in the manual it appears close to the front, would i be able to easily see it with a flash light and clean it out? is it recessed or dangling int he air? i jammed the scrapper in there pretty good i hope i didnt cut it right off :(
You may have damaged it.Shine a flashlight in the exhaust path and see if it's still there.To remove it take the rear covers off and look for the wire coming off the exhaust.You will need a 1/4" socket to remove the nut.
 
You block a portion of the air intake pipe at the rear of the stove on the outside, this is where the OAK would connect.
 
probe is larger then i thought. big long metal thermometer. had a pile of ash on it so i gently got it off then cleaned it off with a cloth so its nice and shiny :)
 
There was a thread not long ago for testing of the ESP by checking its resistance at various temps. Try a search.
 
So its the big fan i want to block flow from correct? not the smaller one? honestly havent noticed a difference on either. I have 60% covered ont he large fan and still insanely aggressive
 
So its the big fan i want to block flow from correct? not the smaller one? honestly havent noticed a difference on either. I have 60% covered ont he large fan and still insanely aggressive

It is air into the stove that you block. At the air intake tube. You do not block any blower or fan on the output side.
 
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Both suck air into the main box as far as i can tell. I dont even see a fan that takes from the box. The larger fan that looks like a snail has a lot of power and is easily blocked. the other moves very little air and is completely open so rather hard to adjust airflow. So... which one do i need to come up with a plan for?
 
The combustion blower is the only one that is creating the air suction in the firebox. The Distribution blower creates the air that passes over the heat exchanger for the heat output over the door.

The incoming air has an auto damper on it that varies (I believe) by the suction of the combustion blower. The air intake is on page 39 item # 3.4-3.6 of the manual.
 
Do you see that round portion of the back of the stove above and to the right of your vent connection, your combustion air comes in there, there is a place to connect an OAK tubing too there, and that is the air flow you want to block a bit.
 
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