Harman p68 used 40Lbs of pellets in 8 hours

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Shoe0402

Member
Dec 15, 2015
60
Pennsylvania
Hi guys I have a harman p68 stove and the other night I turned it on to heat our basement while we were down there and it burned a full bag of pellets in 8 hours. I turned the stove down to the lowest setting in room temp mode. The next night I did the same in stove mode and it burned through a bag in roughly the same time. Both times the stove was on its lowest setting. Any idea why it is burning so much? And what I can do to get it to burn less?
 
Did the room over heat?
 
Hi guys I have a harman p68 stove and the other night I turned it on to heat our basement while we were down there and it burned a full bag of pellets in 8 hours. I turned the stove down to the lowest setting in room temp mode. The next night I did the same in stove mode and it burned through a bag in roughly the same time. Both times the stove was on its lowest setting. Any idea why it is burning so much? And what I can do to get it to burn less?

Is the basement insulated and was it cool down there when you started the burn? A cool basement especially if it's uninusulated or only slightly insulated one can soak up a huge amount of heat.

Is the stove set to auto ignition? If not allowed to shut down completely the stove will keep burning pellets no matter what the real demand. Fourty pounds of pellets in 8 hours is on the order of (40 x 8,000 x .78)/8 or ~ 31,000 btus per hour. That's a good bit of heat. It was in the mid twenties here last night and our p43 set to auto ignition only ran a short time over the whole night.

Hugh
 
Room temp will supply heat as needed to maintain the temperature you dial in - what room temperature do you have set, and what is the temperature in your basement at various locations?

If you want the stove to just idle or burn at a constant but low level, use the stove temperature mode instead.
 
Is the basement insulated and was it cool down there when you started the burn? A cool basement especially if it's uninusulated or only slightly insulated one can soak up a huge amount of heat.

Is the stove set to auto ignition? If not allowed to shut down completely the stove will keep burning pellets no matter what the real demand. Fourty pounds of pellets in 8 hours is on the order of (40 x 8,000 x .78)/8 or ~ 31,000 btus per hour. That's a good bit of heat. It was in the mid twenties here last night and our p43 set to auto ignition only ran a short time over the whole night.

Hugh
Hi our basement isn’t insulated but it never gets much below 50 degrees without any heat. I’m guessing with the stove on our basement was about 65-70 degrees. I tried it in room temp mode and stove mode and both burnt the same.
 
Room temp will supply heat as needed to maintain the temperature you dial in - what room temperature do you have set, and what is the temperature in your basement at various locations?

If you want the stove to just idle or burn at a constant but low level, use the stove temperature mode instead.
I had it turned to 65 degrees.
I honestly didn’t check different areas to se what the temp was. I tried it in both room temp and stove temp and tbey both burned about the same
 
Hi our basement isn’t insulated but it never gets much below 50 degrees without any heat. I’m guessing with the stove on our basement was about 65-70 degrees. I tried it in room temp mode and stove mode and both burnt the same.

It may not get much below 50*F but those concrete walls and floor with direct contact with the earth outside and underneath will be one heck of a heat sink requiring way more energy to keep them warming than one might think.

Hugh
 
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I have a P-68 and when the outdoor temps are low a bag will be gone in 8 hours. It depends on the outdoor temp. A few days ago we had temps in the teens, so I am sure we went through a bag in 8 hours, but those were 8 really warm hours. We got 5 tons this year @$219/ton so I just let her rip and enjoy. I guess you could dial down the feed rate to conserve pellets, but when I do stuff like that people like my wife invariably tell me it is too cold. It is all temp-dependent. On a bitter cold day, I could go through three bags, but in moderate temps a bag might last two or three days.
 
Also, the heating the stove accomplishes will depend on the other areas of the house. I have a first floor stove. Usually we do not use the oil heat upstairs, just relying on the rising heat from the first floor to keep it warm. I noticed last week when the temps were cold the first floor was not hitting a very high temp and the second floor remained pretty cold. I turned on the oil heat up stairs, and that made all the difference downstairs. In your case, if the door above the basement is open or if you have balloon framing, the stove is trying to heat more than just the basement so it affects the result in the basement.
 
As said above the concrete will be a huge heat sync and soak up the heat. It will take 12-24 hours for that concrete to level out to the heat before it really stops soaking up the heat..
 
As said above the concrete will be a huge heat sync and soak up the heat. It will take 12-24 hours for that concrete to level out to the heat before it really stops soaking up the heat..

and if they only heat the basement a portion of the day, it will always be recharging for a good number of hours when the stove is on. If the walls were insulated to just R-5 there would be an amazing decrease in the number of pellets used to warm it up and keep it warm down there.

Hugh
 
I did not read all the comments, so please ignore if it was explained.

Stove mode DOES NOT equal the temp of the room. It uses the 1-7 scale. It does not care about what the room temp is, it only cares about what the exhaust temp is. I do not know the conversion rate, but I typically run at 4 also, 5 on cold nights, in stove mode but our stove is on the 1st floor and not the basement.

I see you're in PA, if this was when it was 9*F, then this would most likely explain why it was running red hot. A bag in 8 hours in a room that is 50*F and trying to get temps in the exhaust to say 350 could be the reason for the fast consumption. I can't say I have used that much that fast, but I only have the P43, I would expect that much more for a 70K BTU compared to a 40K BTU that can burn them up in 12 hours when its in single digits or less.
 
Get a drill with masonry drill bits (you'll probably break a few, so get several), a whole bunch of masonry screws, and a truckload of blue board insulation. Cover your basement walls with the blueboard, then try your stove again.

Our P68 is in our basement, which is half finished. The unfinished side of the basement is cold, so we generally keep the doors closed instead of wasting the heat into that space. We keep the basement door at the top of the stairs open and have a small fan to blow the heat upstairs (the stove fan blows directly at the stairwell). It's our only heat source for most of the first floor, and at 20 degrees outside temp we use approximately a bag a day on igniter disabled room temp set at 75. When it's 30+ outside, I switch to auto ignite, then it turns on and off every couple hours or so.
 
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On stove mode, I have never been able to use only one bag a day...
Usually 1-1/2 to 1-3/4. on #2.
The p68 is a pellet monster.

Dan
 
Hi our basement isn’t insulated but it never gets much below 50 degrees without any heat. I’m guessing with the stove on our basement was about 65-70 degrees. I tried it in room temp mode and stove mode and both burnt the same.
A uninsulated basement wall is like a heat sink. The heat gets absorbed by the blocks and all the cold dirt around the basement walls. Having said that a P 68 is capable of producing 68,000 btus . this will eat up a lot of pellets.. The 68 is known for producing a lot of heat but you are trying to heat the walls and dirt on the outside of the walls. If you were to insulate the walls you would be amazed at how much less pellets you would use.
 
Finally got some people to give accurate pellet usage . most guys say with that P-68 they use one bag a day and keep the temp at 70. Only when it is 30 -40 with my P-43 can a get 20 hours out of a bag at 68.
 
I have a P61A and in stove mode, I will go 2 bags/24hrs easy.....
and this is a poorly insulated house with many many windows.. soooooooo, the P68 bigger beast appetite sounds normal..
 
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claims of "one bag a day with a P-68 set at 70" is that 24/7 burning? must have a super tight house or not terribly cold outdoor temps..
don't think my P61A would ever get 24hrs out of a bag unless on room temp mode and many many rampdowns during the day. maybe.