Please help with heat output on my Harman Accentra

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tpme06

New Member
Sep 6, 2012
41
Newmarket, NH
I just bought a (used) Harman Accentra insert that was only used for 1 season. I do not have an OAK, but have a full lining up to my chimney cap. I put insulation around my damper area to help with any drafts. My father in law just bought a new Englander pellet insert (not sure of the model, but looks a bit smaller than the Harman). I believe his stove takes in outside air, and he has his lining running up 5 feet at the moment.

We are both using the same pellets (Fireside Ultra), and when his is at a heat setting of "2" with the blower on "7", and mine is on a stove temp setting of "2" and my blower on medium, his stove is MUCH noticeably hotter. My air feels luke warm, where his is nice and toasty. Would an OAK kit make a huge difference? I did the install with someone who worked in the stove business for a long time, but could he and I installed something wrong? I'm really not impressed with the heat output of my Harman, as it's having trouble keeping a 15x15 room with cathedral ceilings above 70 degrees unless I crank the blower and stove temp to 6-7. Any thoughts? I really appreciate any insight as I try to figure this out...
 
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Why don't you set it on 70 degrees and room temp with a feed rate of 4 and see what happens. The stoves operate far different from each other.
 
I'll give that a try. The reason I was setting it on stove temp was to try to mirror the same pellet usage as his (he said his was burning roughly 1.5-2lb per hour). I'm sure it will hold 70 on room temp, but I don't want to be burning 6lb's an hour to do so when I feel like it should be using a lot less. My concern is efficiency, as I've seen other stoves (Harman and others) that are putting out lots of heat using only a couple lb's an hour. Thanks a lot of the info though, I'll be testing that tonight.
 
firstly, dont expect your accentra to be "hot to the touch" except the glass. Do you know if the unit was cleaned propperly before you installed it (heat exchangers, and exhaust path especially-these are commonly ignored or not cleaned correctly)? Make sure your "feed adjuster" is set to 4-ish and ignore it (for most applictions).
 
Set it on room temp 70 and forget it. Mine seems to run much better in room mode then stove temp. I switch the ignition to manual after it is running to stop it from cycling off. I only use stove temp mode when outside temps are in the 50s
 
lets start with with low hanging friut.

1) is the stove really really clean and did YOU Personally run the vent brush all the way through the exhaust vents on the bottom of the stove. Most owners who have these stoves forget to clean that out and one whole half of the stove becomes clogged and you loose significant efficiency. Then they sell them without every understanding what happened.

2) Even if you have already done this cleaning do it again and make sure you can put the brush all the way in to the top of the handle in the left side and can see it in the right side. If you can not do this then it is clogged...

3) Have you done a proper set up. Set the feed rate so that at max burn you are getting 1/2 inch of ashe and no pellerts are overflowing the burn pot. Once this is done mark your feed rate as that is your highest you want it set at.

4) Your distribution blower is different than your father inlaws as such you need to compare it to a common blower and at a common speed. Faster is more efficient but the output air is cooler. Slower creates hotter air but your BTU transfer rate will actually drop. I could get into this with physics and thermodynamics but the best to say is you need to measure your air temp. Get a long meat thermometer and set it in the distribution grate and measure the temp of the air not the steel you want the end to hang in the air. You are looking for that temp. you want to see where it stabilizes once the room comes up to temp. at least 3 hours after start up. I like to see my stove in the 150 range about 4 inches behind the grate..... If I start to see that temp drop by say 10 degees it is time to do a cleaning.

5) Consider setting up on room temp it is more efficient in the long run.

6) The OAK make a difference in that you do not have to suck cold air into your home through all the cracks and heat it up to room temp only to blow it back outside. With the oak installed you burn cold air and your warm inside air stays inside longer.
 
I have a Harman Advance which Is similar In controls to your Accentra. The easiest way to explane the two modes of operation to you Is the way It was explained to me. The stove temperature mode Is like a fireplace. You set a temperature and when the stove meets this temp. the flame will stay large but most of the heat will go up the chimney. (Wasting pellets) I only use this mode when we are watching the Patriots with a few friends (For the Ambiance). Most of the time I use the Room temp. mode. Set the temp. at 70 deg. and the room temp. dial set at 12.00 o'clock. Feed rate set at between 3 and 4. From a cold start the stove will come on and produce a large flame and start making a lot of heat (And using a lot of pellets) When the temperature probe senses the 70 deg. in the room has been met the stove will throttle down and just loaf alone to maintain the set temp. My bride lit the stove off this morning at 6:00 Currently It is 70 deg. in my living room and 34 deg. in Plaistow and the stove is on lo fire and just barely using pellets. I would guess I am using 1-1/2 to 2 lbs. of pellets per hour. Try this way I am sure you will be happy.. Then do what a lot of people do when bragging to there friends who have stoves about there stove and pellet usage. LIE
 
Everyone, thank you for the responses. This forum is such a huge help.

To measure the two stove temps I was just holding my hand about a foot away from the blower, and noticed a difference there. I wasn't actually feeling the stoves or taking an accurate temperature measurement, but I did notice a big discrepancy.

I did clean the stove myself, and can run the brush all the way through the exhaust vents. I take out all the pieces (excluding the burn pot, but I do scrape that clean if it needs it) on a weekly basis and clean them, along with using the brush in the exhaust vents. I vacuum the stove out at the end to be sure I got all the little stuff. I have about 1" of ash at the edge of the burn pot, so it's set up to the best of my knowledge, I never have pellets drop off the edge. I will adjust my feed rate to try to get the 1/2" inch you were talking about.

I may have misunderstood the stove temp mode, thinking it puts out constant heat. If I am in fact losing heat as Jim from NH described, that would certainly explain it. I'm going to put it on room temp tonight and give that a try for a week or so to measure my pellet consumption and see if I get the results I was expecting.

Again, thanks everyone who contributed, I feel much better about my purchase. I'll update in a few days or a week.
 
I have the Accentra insert upstairs and the Accentra free stand in the cellar. When they are set up and running properly you'll have to open windows and doors to cool off the house.
I run my stove on room temp and if I recall the feed rate is close to 4 and the upstairs stays around 70-72, I burn roughly 1 bag of pellets per day.
 
I have the harman accentra and was wondering if when you cleaned the stove that you cleaned the ESP probe. that will effect the heat out put. when you run the harman you should just leave the feed rate at 4 it will adjust automatically. I keep my stove on 70 and feed rate of 3 also on stove temp last winter when it was 5 degrees out my living room which is 30 x 12 with 8 foot ceilings was at 74 degrees and my kitchen and 3 bed rooms were at 70, I have fans in all the bed rooms and blow a small fan into the kitchen. I love this stove 2 years ago i went through 3 tanks of oil and last year i only used 1/2 tank of oil and went through 1.5 tons of pellets

try this link http://www.harmanstoves.com/Custome...tions/AccentraInsertCleaningInstructions.ashx
 
Put it on room temp last night. 70 with a feed rate of 3 with the blower at 12 o'clock. My little 15x15 room managed to stay just about 70 and my hallway at 67. Beyond that all the other rooms were just over 60 or under.

The good news is that the stove was much hotter, but it went through a bag in 14 hours. I'm going to put it at 75 tonight and see what happens, but I'm certainly not getting the output I hoped for. It's working pretty hard to keep 300 sq feet at 70. Guess I'm going to be using a lot more oil than I thought!

I have a pocket door that cuts the house in half. My hope was I could heat the 600 sq feet where the stove is, but it seems doing so may actually cost me more with pellets than it would with oil. I calculate about 4 tons this winter to keep that amount of space just over 70 on evenings and through the night, with the stove off during the day.
 
Something has to be funky on your stove, a 15 x 15 room and you went thru 1 bag in 14 hours??
 
The stove feels like it's putting really warm air out. I wonder if it could be creating a draft and is pulling the cold air from the rest of the house into the room. Either that or the insulation (or lack there of) is poor in the cathedral ceilings. Either way, this is very upsetting :(
 
Welcome to the form.

Have you read the sticky on how your Harman works? Good down to earth info there.

Here's how I run mine. Stove temp auto mode 4 , feed rate 4 , blower on low this keeps my 400 sq. ft. space a comfy 70 and I avg. 24 + hrs / bag have gotten as high as 30. I have R 30 in the roof and R 19 walls with good windows. You mentioned insulation or not in the ceiling that maybe your issue. Do you have a ceiling fan to push heat down? This set up works for me it may not for you all you can do is try, experiment .

Jim mentioned that stove temp was like a fire place big flame heat going up chimney that is true if you are running in manual mode blower won't come on make sure you are in auto heat will be pumped in to the room.

Hope this helps and you can get this puppy working like it should.

Will
 
Will711
My son has a Harman Advance insert located in a 20x24 room with cathedral ceiling If he sets the temp at 70 the stove will bring that room up to the desired temp The rest of the house (A rather large one) will be cooler, and he does have to run the oil furnace for the rest of the house Remember a pellet stove is a SPACE HEATER Both he and I haveR-30 In the ceiling and R-19 in the walls with new windows . What is the size of your house and how much insulation do you have? With that stove you should have no problem heating a 15x15 room unless you are living with year 1920 insulation.
Jim
 
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Will711
My son has a Harman Advance insert located in a 20x24 room with cathedral ceiling If he sets the temp at 70 the stove will bring that room up to the desired temp The rest of the house (A rather large one) will be cooler, and he does have to run the oil furnace for the rest of the house Remember a pellet stove is a SPACE HEATER Both he and I haveR-30 In the ceiling and R-19 in the walls with new windows . What is the size of your house and how much insulation do you have? With that stove you should have no problem heating a 15x15 room unless you are living with year 1920 insulation.
Jim


Hey Jim,
I think you wanted to address this to tpme06 not me, and I totally agree with you that stove should pump heat into that room insulation may be the issue.
 
House is from 1971 and is 1700 sq feet ranch style, not sure what the insulation is in the ceilings, but I added another r30 to my attic to make it over r40. I keep the stove on automatic and I do have a ceiling fan that is on. I bought the stove hoping it would heat the 15x15 family room and warm up my bedroom down the hall a little, I don't think my expectations were too high, as I know it's a space heater. Looks like it could be the insulation, maybe I'll get a thermal measurement tool. All my heat is probably going right through the ceiling!
 
House is from 1971 and is 1700 sq feet ranch style, not sure what the insulation is in the ceilings, but I added another r30 to my attic to make it over r40. I keep the stove on automatic and I do have a ceiling fan that is on. I bought the stove hoping it would heat the 15x15 family room and warm up my bedroom down the hall a little, I don't think my expectations were too high, as I know it's a space heater. Looks like it could be the insulation, maybe I'll get a thermal measurement tool. All my heat is probably going right through the ceiling!

Just so I'm clear and on the same page this 15x15 room has R40 or is this an addition ?
 
The 15x15 room is an addition and there is no attic space above it, so no added insulation aside from what was originally put in there. the ceiling I added insulation to is on the other side of the house
 
The 15x15 room is an addition and there is no attic space above it, so no added insulation aside from what was originally put in there. the ceiling I added insulation to is on the other side of the house

Now it makes sense . Thanks . My guess is that not much is up there. Keep us posted .
 
I have a Harman Advance which Is similar In controls to your Accentra. The easiest way to explane the two modes of operation to you Is the way It was explained to me. The stove temperature mode Is like a fireplace. You set a temperature and when the stove meets this temp. the flame will stay large but most of the heat will go up the chimney. (Wasting pellets) I only use this mode when we are watching the Patriots with a few friends (For the Ambiance). Most of the time I use the Room temp. mode. Set the temp. at 70 deg. and the room temp. dial set at 12.00 o'clock. Feed rate set at between 3 and 4. From a cold start the stove will come on and produce a large flame and start making a lot of heat (And using a lot of pellets) When the temperature probe senses the 70 deg. in the room has been met the stove will throttle down and just loaf alone to maintain the set temp. My bride lit the stove off this morning at 6:00 Currently It is 70 deg. in my living room and 34 deg. in Plaistow and the stove is on lo fire and just barely using pellets. I would guess I am using 1-1/2 to 2 lbs. of pellets per hour. Try this way I am sure you will be happy.. Then do what a lot of people do when bragging to there friends who have stoves about there stove and pellet usage. LIE

I don't believe this is how stove temp works - stove temp maintains the temp at the esp, but the heat is always blowing into your house.
 
Not Completely true
Read excerpt from Harman Manuel
Stove temp - 100% driven the the ESP (temperature probe in stove exhaust flow). Temp dial corresponds to a fixed ESP temperature. For simplicity, let's assume a setting of 3 = 300 degrees ESP temp. The stove will ramp feed up/down to always be as close to 300 degrees as possible. In stove temp the stove doesn't care what the room temp is, only the ESP temp. The room might be 60 or 90 degrees doesn't matter, all it cares about is maintaining an ESP temp of 300.The stove will not shut off in stove temp regardless of whether the igniter switch is set to auto or manual. Stove temp, switch to manual - I call this fireplace mode. Distribution fan will not turn on unless the temp knob is set to 5 or higher. This is designed to give a nice fire, but not a ton of heat in the room. Most goes up the chimney. Stove temp, switch to auto - distribution fan operates normally to push heat into the room, regardless of stove or room temperature. There is a caveat to this, if you have your room temp set to 1 (very low) then the distribution blower might shut off because the ESP temperature is below the lowest setting allowed for the distribution blower to run.
 
Not Completely true
Read excerpt from Harman Manuel
Stove temp - 100% driven the the ESP (temperature probe in stove exhaust flow). Temp dial corresponds to a fixed ESP temperature. For simplicity, let's assume a setting of 3 = 300 degrees ESP temp. The stove will ramp feed up/down to always be as close to 300 degrees as possible. In stove temp the stove doesn't care what the room temp is, only the ESP temp. The room might be 60 or 90 degrees doesn't matter, all it cares about is maintaining an ESP temp of 300.The stove will not shut off in stove temp regardless of whether the igniter switch is set to auto or manual. Stove temp, switch to manual - I call this fireplace mode. Distribution fan will not turn on unless the temp knob is set to 5 or higher. This is designed to give a nice fire, but not a ton of heat in the room. Most goes up the chimney. Stove temp, switch to auto - distribution fan operates normally to push heat into the room, regardless of stove or room temperature. There is a caveat to this, if you have your room temp set to 1 (very low) then the distribution blower might shut off because the ESP temperature is below the lowest setting allowed for the distribution blower to run.

Hence, why I keep it on stove temp auto - especially during the colder months (as do a lot of the other Harman owners on here) because then the stove doesn't spend time ramping up and down maintaining heat according to the thermostat. I heat my whole house with my Harman, so I keep it on stove temp which keeps the back bedrooms warmer. I've found stove temp to be the most efficient/effective during cold weather.
 
movemaine, I too run my Harman p68 on stove temp, been doing it going on 6 years. When it's really cold it's the best way to heat your whole house, just keep that warm air steady going through your house.
 
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