Harman P68 start up fire too big

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jettech

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Apr 4, 2013
13
martinsville, IN
When my Harman P68 lights off it produces a huge flame that bounces off the top and sides of the fire box and blackens the top of the glass. After a short time the flames catch up to the amount of pellets in the burn pot and it burns well with a smaller hot flame. It has done this since the first light off when it was new. I keep the stove clean and have cleaned the area under the burn pot and made sure all the holes in the floor of the burn pot are open. It takes between 5 and 6 minutes to have a flame going. It has stopped feeding pellets before the flame starts. It seems like either too many pellets are being fed initially or the ignition is slow getting the fire going. I've inspected the igniter and it appears to be in satisfactory condition.
 
basically normal, but, FYI, you can change the timing of pellets upon ignition to the burnpot by changing some dipswitch settings on the board. Im not comfortable with folks doing this, as if a mistake is made, it makes it tough to diagnose issues later.....suffice to say tho, that with less pellets in the pot, youll have a smaller fire.
 
To Lousyweathers point: Is it possible the dip switch settings are incorrect?

The start up time seems about right. Perhaps try a few different brand of pellets.

I have never seen that behavior with my XXV. The flame starts off small and fierce and grows once the esp senses heat. Feed rate is 4.
 
personal preference and not a harman recommendation but i find the best and quickest, cleanest lights come from when the pellets just touch or cover the row of holes closest to the auger. if your pellets average short 1/4"-1/2" (such as sommersets) the factory setting will work but adjusting the charge time or time the auger is run on start up will possibly get you better results.
 
You will have the same thing happen if your stove is running set for 65 and you turn it up to 75, the stove will feed like crazy to get up to the set temp. My P61 has operated like this since I bought it. To minimize this, when you start your stove, just have the temp setpoint set low. It will still feed like you described, just not as long. You then can work the temp up at the rate you want. Better yet, start the stove in stove mode. Doesn't seem to big as big of a problem.
 
the more pellets that get fed into the burnpot prior to ignition will always give you a larger fire......as for XXV versus the OP's P68......different firebox size, different burnpot....different startup. Also, and not saying this is the deal-io here, but as your igniter gets dirtier, your ignition will also be delayed, causing that larger fire.....sometimes even a pressure wave when it ignites......

could the switches be set wrong? well, if someone monkeyed with them, sure (pretty sure the OP didnt).......all I was saying is you can actually alter the amount of pellets for ignition with the right combo of switch settings......more likely slightly dirty unit if this is a new circumstance......
 
"Startup fire too big". That's what she said?
 
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basically normal, but, FYI, you can change the timing of pellets upon ignition to the burnpot by changing some dipswitch settings on the board. Im not comfortable with folks doing this, as if a mistake is made, it makes it tough to diagnose issues later.....suffice to say tho, that with less pellets in the pot, youll have a smaller fire.
Thanks this is what I was hoping to find out more about. I'm using Lignetics premium pellets, keeping it cleaned and the stove works really well other than this small problem. I would like to make an adjustment to the pellets upon ignition timing but need to know what to adjust. I've had the board out but its not obvious to me what to adjust. There are 3 pot type adjustments but I'm not sure if these are called dipswitches and which one I should adjust and which direction. I'll keep track of the original settings in case I need to go back to them.
 
I had a (possibly) similar issue with late ignition/large fire with my new stove (P61A). It turned out that the ignitor wasn't exactly in its cradle correctly. So, sometimes it lit normal, other times it lit very late with a huge fire, and other times it would not light at all and I had to start the ignition process over.

After correcting the ignitor position everything returned to normal.
 
Thanks this is what I was hoping to find out more about. I'm using Lignetics premium pellets, keeping it cleaned and the stove works really well other than this small problem. I would like to make an adjustment to the pellets upon ignition timing but need to know what to adjust. I've had the board out but its not obvious to me what to adjust. There are 3 pot type adjustments but I'm not sure if these are called dipswitches and which one I should adjust and which direction. I'll keep track of the original settings in case I need to go back to them.

Pot(entiometers) are variable dials that are turned, dip switches are on/off: very different things.

I wouldnt make changes to anything that you dont know what it is for. Do you have the default settings for the dip switches ?
 
I have them, just not handy at the moment. Can post later if someone does not beat me to it.
 
Hell, big fire get's the stove hotter quicker meaning hot air comes out sooner. What's wrong with that?
 
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The dips for the P68:
6 rpm auger - on off on off on on on on
4 rpm auger - on on off off on on on on
 
Hell, big fire get's the stove hotter quicker meaning hot air comes out sooner. What's wrong with that?
one is as lousyweather already stated it can cause a "flashover" like event that can be quite loud sometimes, also it will generally smoke more than normal on startup which over repeated lights can buildup small amounts of creosoot, especially on the screen of the chimney cap in cold weather which makes the screen sticky and collect lots of fly ash then it will clog very quickly compared to what is normal. a smaller amount of pellets usually lights faster also leading to the igniter being on for less time as well.
 
Slow ignition causes a flashover, not the size of the fire or the amount of pellets in the burn pot trying to ignite.
 
Slow ignition causes a flashover, not the size of the fire or the amount of pellets in the burn pot trying to ignite.
correct, though there are three major things i can think of that causes slow ignition. lack of air flow, lack of heat transfer from the igniter to the air, and too many pellets in the fire pot on start up.
 
Pot(entiometers) are variable dials that are turned, dip switches are on/off: very different things.

I wouldnt make changes to anything that you dont know what it is for. Do you have the default settings for the dip switches ?
Thanks good to know. I'll look at the board closer. I didn't see the dip switches the first time.
 
The dips for the P68:
6 rpm auger - on off on off on on on on
4 rpm auger - on on off off on on on on

be careful here, folks, because this isnt entirely correct.....why i avoided putting settings on here in the first place.....
 
well, for starters, which ESP probe do you have? Your settings assume the digital ESP probe is in place, whereas, you can find either the analog ESP, OR the digital ESP in a P68.....precisely why I avoided putting settings here.....the problem is, folks THINK they may have a problem which may or may not be rectified by changing these switch settings, and make diagnosing any issues in the future MUCH more difficult, due to the fact that the switch settings may be incorrect.....
 
I had a similar problem with my p61a. For me, keeping the feed rate at one until ignition has done the trick. As soon as I get a fire going I move the feed rate up to 3 or 4.
 
That's true. In my haste I did not think to include the breakdown. To be complete:

Dips 1-3 are for the ignition cycle. The quantity of pellets augered in the burn pot.
Dip 4 is factory set to off for power failure shutdown with inline ups
Dip 5 is for ESP type. Off for any type of ESP that is not red wire.
Dip 6 is for room sensor differential. On reduces the difference by 1 deg
Dip 6 is for boilers. On when using atmospheric kit.
Dip 7-8 sets the max ESP temp.

The op seems to be interested in verifying his first three dip settings 1-3.

Lousyweather please jump in to correct any information you feel is inaccurate.
 
I had a similar problem with my p61a. For me, keeping the feed rate at one until ignition has done the trick. As soon as I get a fire going I move the feed rate up to 3 or 4.

I dont beleive the feed rate has any bearing of feed rate upon ignition, but, glad your method works for you
 
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