Harman feed setting

[turbosporsche]

So I read a lot of posts about feed setting and kinda stuck. I was having issues with what I thought was a lazy flame. My manual says to set stove on 4 feed setting the sticker on the inside of the door of the control board says 3. I noticed that if I have it around 2 2.5 I get a flame that is very rapid clean hot and stays that way much longer.

I checked my fine tune screw for blower and that's all way up.

I'm wondering since my batch of hamers are on the shorter length that cutting back the feed helps to burn them better.

Any thoughts

 

[Rastallama]

Did you see this thread that just started?

https://www.hearth.com/talk/threads...-different-grade-pellets.118546/#post-1586314

So far, anecdotally, it seems "higher quality" hardwood or ALL softwoods seem to need a feed adj setting around 2.5 where as many of the others brands i burn seem to do better with a feed of 3.5-4
That is what i see re flame size and ash line at the burn pot lip.

And this is when you control for room temp mode, room temp, and fan setting, but not for outside temp.

 

[turbosporsche]

Just saw it. Good to no about feed. I was chasing possibly bad blower or leak somewhere. Thanks

 

[Rastallama]

Just saw it. Good to no about feed. I was chasing possibly bad blower or leak somewhere. Thanks

Yeah well, I'm getting spanked on that other thread about my settings... So take my newbie info for what it is!

 

[Don2222]

Hello

I know Harman changed the algorithms in their chipset in newer circuit boards. The old Harman philosophy was "set the feed rate to 3" The older circuit boards like my old P61 board made the stove run hotter, that is why the lower feed rate of 3 on the old door stickers. The new circuit boards have been toned down for better heat control and their feed rate setting should normally be 4.

So this is why the newer manual states to set the feed rate even higher for more ashy pellets that give off lower heat.

From the Harman P61a manual page 16 version 3-90-05822R24_03/13
Feed Adjuster Knob
For most premium grade pellet fuels the Feed Adjuster
Knob should be set at 4. If higher ash fuels are used
the setting should be increased to 5 or 6. Also higher
settings are required if you would like to get the
maximum heat output from the stove. At the maximum
burn rate (with the temperature dial on 7/90° and the
feed adjuster at 6) there should be 1" or more of ash
on the front of the burn pot. If there is less than 1" of
ash, turn the feed adjuster knob down to a lower setting.

See Feed Setting #3 in pic below

 

[lessoil]

Hello

I know Harman changed the algorithms in their chipset in newer circuit boards. The old Harman philosophy was "set the feed rate to 3" The older circuit boards like my old P61 board made the stove run hotter, that is why the lower feed rate of 3 on the old door stickers. The new circuit boards have been toned down for better heat control and their feed rate setting should normally be 4.

So this is why the newer manual states to set the feed rate even higher for more ashy pellets that give off lower heat.

From the Harman P61a manual page 16 version 3-90-05822R24_03/13
Feed Adjuster Knob
For most premium grade pellet fuels the Feed Adjuster
Knob should be set at 4. If higher ash fuels are used
the setting should be increased to 5 or 6. Also higher
settings are required if you would like to get the
maximum heat output from the stove. At the maximum
burn rate (with the temperature dial on 7/90° and the
feed adjuster at 6) there should be 1" or more of ash
on the front of the burn pot. If there is less than 1" of
ash, turn the feed adjuster knob down to a lower setting.

See Feed Setting #3 in pic below

We had our board replaced 1 year ago. Would this board be a "new" board?
I have noticed that the start up is different than with the old board.

Thanks
***Put feed rate on 5 for testing***

 

[turbosporsche]

All I no is if I put my setting on anything over 3 the flame gets lazy and black smoke happens. The ash line stay the same on either 2 2.5 up to 4. My option is that the feed needs to be set to each stove per pellet type. Since no two pellets are the same in length or size or quality. I'll keep mine at 2.5

 

[Harman Lover 007]

Yeah well, I'm getting spanked on that other thread about my settings... So take my newbie info for what it is!

I wasn't spanking you....

 

[Harman Lover 007]

All I no is if I put my setting on anything over 3 the flame gets lazy and black smoke happens. The ash line stay the same on either 2 2.5 up to 4. My option is that the feed needs to be set to each stove per pellet type. Since no two pellets are the same in length or size or quality. I'll keep mine at 2.5

You've got other issues with what you describe above and the feed rate isn't the problem.

 

[turbosporsche]

You've got other issues with what you describe above and the feed rate isn't the problem.

Like what

 

[Harman Lover 007]

Like what

To me, black smoke and a lazy flame are combustion problems, not a feed rate problem. I'd be checking my air intake path, the combustion path including venting and if I had access to one, I'd use a DDM to check the draft.
Have you ever performed Harman's recommended feed rate set procedure? It's in the link in my sig.

 

[IHATEPROPANE]

When you set a max feed rate on a Harman does it go to that set rate when the esp calls for heat? I don't have a Harman but from reading this forum my understanding was that the esp would choose the best feed rate needed to get the room or stove to the correct temp up to the max feed set.


After reading this post it seems that it goes from a low setting to the highest?? I say this because I cannot imagineany scenarios where the Harman would have to run at 80% of its max feed unless it was maybe the p35?

Therefore setting it at 4 should only change the burn characteristics under extremely cold conditions...otherwise it would be burning at a lower rate.

Am I correct in this thinking?

 

[Harman Lover 007]

Exactly..... and apparently, hard as I try, I just can't articulate that very well. Below is the "best" description I've ever read that relates to Harman feed rates. This is a cut and paste from the Sticky above and in my sig from forum member "lbcynya":


Feed Rates - Feed rate is controlled by the stove ESP. The stove will select a feed rate based on the actual temperature and target call for heat. The larger the temperature delta (actual room temp vs. target room temp), the greater the feed rate will be. 10 degrees would be a large delta and the stove would feed to reach max ESP temp of about 500 degrees depending on stove model. A 2 degree delta might only result in a feed rate of 20 seconds per minute even though the feed rate max dial is set to 4 (or 40 seconds per minute). The stove can vary the feed rate between 2.5 seconds per minute and the max feed rate you set. A feed rate of 6 would represent continuous feeding if the ESP wasn't seeing sufficient temperatures to satisfy the call for heat. When up to temp the stove will regulate itself form 2.5 seconds per minute of feed up to the limit you set.

Feed rates can lead to incomplete combustion comes in 2 forms:

1. Pellets spilling over the edge of the burn pot before they are reduced to ash.
2. Smoke.

Relative to #1 - when you run the stove wide open (stove temp setting at 7), the burning pellets should come no closer than 1 inch from the edge of the burn pot. You should have burning pellets and about 1" of ash before the edge. If pellets are bulging and close to the edge, you might not turn them to ash before spilling over the edge, wasting energy. If the burn line is too close, dial the feed rate back a bit, may by 1/2 of a number (i.e. 3.5 to 3). The stove doesn't run wide open once everything is up to temp, so this is only for scenarios where, for instance, the room is 65 and you want it 75 degrees or you turn the temp dial all the way clockwise (just don't walk away for too long or you'll bake yourself...).

Relative to #2 - smoke is also a sign of incomplete combustion, meaning that there is more fuel than air supplied by the combustion blower. This too should be evaluated when the stove is running WIDE OPEN. At night with a flashlight, you'll always see smoke. During the day, smoke is rated based on opacity or how easily you can see through it. Startup might be 50% opacity or fairly heavy smoke. If you are 10% or less (barely visible), that's reasonable and you aren't really wasting anything. If you have to struggle to see it, you're probably good. If you can easily see smoke and your flame is HUGE, try dialing back feed rate a bit to bring the air/fuel mix back into a more efficient range by dialing it back by 1/2 of a number (ie 3.5 to 3). In most cases, you don't want to be below 3 or much above 4. You'll also want to recalibrate after changing brands of pellets since the blend and size of pellet will cause it to burn/feed differently.

Setting your feed rate too low doesn't save pellets and stove performance will suffer since your inhibiting the ESP from reaching target temps. Setting your feed rate too low is like putting a brick underneath the gas pedal of your car.

Don't be tempted to set your feed rate too low.

 

[IHATEPROPANE]

I read that sticky a while back.....good stuff.

So would it make sense to set your max feed rate as high as possible and still get that 1" of ash? And adjust accordingly to change in pellet brand?

I would bet Harman recomemdation of 4 would be good for the majority of pellets