Harmon accentra won't feed more than 3lbs / hour

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smirnov3

Feeling the Heat
Feb 7, 2006
440
Eastern Ma
I have a Harmon accentra insert. I have had it for over a year and I just realized that it's max feed rate is 3 lbs per hour.

isn't the max xupposed to be 4 per hour? Is this likely to be a controller issue, or what?

he're the situation:
Feed dial is maxed out
temp dial is set to 80 F
air blower on high

outside temp 28-32

inside temp 65F

the flame height varies from high to medium. The pellets are in no danger of overflowing the pot.

I loaded the stove at 4pm on friday. it flamed out around 10 am on saturday.
hopper holds about 50 lbs of pellets (just less than a bag and a half)

anybody know what's going on?

I don't want to call the service guy, and have him waste a couple of hours for something that I can fix myself in a couple of minutes (or worse yet, have him scratch his head and shrug his shoulders before he drives off into the sunset with my money, and no repairs)
 
i dont know the workings of the units controls , but , my question may have bearing;

does the unit have a way to run without sensing the rooms temp via the probe? maybe the probe is not calibrated correctly and is telling the board that the room is warmer than it really is


just a thought , hope it helps ya
 
stoveguy2esw said:
i dont know the workings of the units controls , but , my question may have bearing;

does the unit have a way to run without sensing the rooms temp via the probe? maybe the probe is not calibrated correctly and is telling the board that the room is warmer than it really is


just a thought , hope it helps ya

that's what I used to think, when I used to set the stove to 70, and the temp was 65 (which is about where I wanted it)

but at a set temp of 80F... for it to be miscalibrated by 15 F is kind of much.


I ran it once in stove mode for about an hour, and the flames also alternated height between medium & high, just the same as in room temp mode.

I can try running on stove mode for a protracted period & see what happens.
 
Maybe the ESP is limiting the feed rate because of high temp due to poor venting or bad ESP itself?

Did you try Stove Temp mode with all controls maxed out?
 
ok, I tried running in Stove temp mode, does not improve performance

my dealer is claiming that the problem is just that the stove distribution fan is dirty. it is, but in my opinion, that has nothing to do with the feed rate - it just would mean that the stove would use MORE pellets, as it would run at top speed more of the time.

also, the reason that it is dirty is because the dealer didn't provide me with a set of rails to pull out the stove onto. does anybody know where I can get a cheap set of rails in the boston / norwood area?
 
GVA said:
Have you checked commonwealth stove on rt 1 norwood?

they're the guys that are claiming that it's a dirty blower problem, and refused to listen when I told them that I had the stove set to 85F, and the feed maxxed out (their responce is "don't do that - it's too high")
 
Anton Smirnov said:
also, the reason that it is dirty

Have you CLEANED your vent?

I would think a malfunctioning room air blower would probably cause a reduced feed rate because the heat is going out the vent and not into the room. The ESP temp tops out and the feed rate is reduced.
 
Anton Smirnov said:
GVA said:
Have you checked commonwealth stove on rt 1 norwood?

they're the guys that are claiming that it's a dirty blower problem, and refused to listen when I told them that I had the stove set to 85F, and the feed maxxed out (their responce is "don't do that - it's too high")
No I meant try them for the rails..... Have you checked with Harry?

I would get the stop watch out and time the auger feed rate with what you have it set at.
You could have a bad or dirty (feed rate) potentiometer, which would warrant replacement of the board, just another possibility.
Could be the ESP regulating the feed rate down too, so I would time it right after ignition and the Distribution blower comes on (proof of fire has been made).
and then an hour later and then compare.
and though unlikly make sure the cam follower is still attached to the driven sprocket (the one that moves the horseshoe cam for the slide plate) and make sure on the auger gearmotor that the output shaft is turning when the stator is turning, it could be slippage in the gears...
 
Hi What are these rails you are talking about? I wondered about accessing the back of mine, and seeing as its in the corner is going to be a real pain to get in there to pull panels, and clean. Does anyone have any suggestions onhow the easiest way would be to do this?? I googled for pellet stove rails but come up empty. I was thinking mabe I could unhook the flue and have someone help me to pick it up and spin it, but Id rather try and do it myself, and dont want to scratch the hearth pad I paid a small fortune for. Any advice ? Thank you
 
A "poor man's" rail kit can be made from 2 x 4s. The front of the stove behind the bottom trim has two sockets that are the size of 2x4s. The you cut vertical legs the height of your hearth. Its a bit harder to pull out than the rail kit, but far cheaper.

SMK
 
Regarding the original post:

As suggested, put the feed rate on 6 and the stove in STOVE TEMP on 7. Let the stove burn for 30-45 minutes. Leave the control door open so you can see the lights on the board. With these settings, you should be in virtually continuous feed. That means the FEED MOTOR light should be glowing all the time. If it is not, then you have a draft problem that is causing the draft differential swich (vacuum switch) to intermittantly open and close, leading to irregular feed. Let me know what you find.

SMK
 
I have a Harman Accentra- freestanding, but thought I'd let you know that I have had 2 thermostats/temp probs that were way, way off- Ihave to turn mine to about 70 degrees to get it to turn on, when it is 62 degrees in the house. The thermostats are worthlees in my limited opinion!
 
Placement of the room probe is the biggest factor when customers are unhappy with the stove's ability to maintain temperature. The probes are far more sensitive than a wall mounted thermostat and can respond adversely to drafts or being in contact with the floor or the hearth. The stove is attempting to maintain a temperature at the point where the room probe is located. That particular spot (i.e. behind the stove) may be considerably colder than the chair across from the stove. This will make the discrepancy between the set point on the stove and the actual temperature in the room appear larger than if the probe were located near wher the customer spends most of their time. Obviously, if the probe is in a warm place, the opposite is true. That's why they can be extended up to 100 feet.

SMK
 
The temp sensor and temp setting are NOT like the similar setup on an oil furnace. At least not in the Harman P68. Coming from a geek side, I'd say the tuning loop for the sensor is very long. When you make a adjustment on the oil furnace, the thing comes on pretty quick, gets up to temp, and shuts off. When you make an adjustent on the pellet stove, it goes through the same type of cycle, comes on, up to temp, and moderates down. But this is over a ;long period of time. I find most of the complaints I hear locally are because people don't realize this. I actually find it a minor pain to lower the temp at night, and bring it up in the morning. I usually just set it for comfortable, and leave it. AND, when I make an adjustment, I ignore the darn thing for an hour, then checkit !

Second note, especially on the Harman, that room temp setting is also able to make a large change in how the sotve works. Put it in the low setting, and it cycles on and off more like an oil furnace, and the temp will vary up and down as it does. If you don't mind that blower running more, put the setting nearer the high setting, the blower runs more, BUT the temp doesn't vary at all. Last year the outside temp varied -22 to plus 30 in January. The temp inside my house varied 2 degrees over a month time frame.

To me the pellet stove is NOT an oil furnace , not an instant gratification heating device. But rather a stable, long term, heat source. Maybe we need someone to write the Zen book of pellet stoves, and tell people to be one with your stove !
 
I did a thorough cleaning (the room air / distribution fan was a pain to get at, and it was not as badly filthy as I had feared, with three cats in the house)

I used wood instead of rails. cheaper.
And a hammer to get those tough clinkers off

But the stove is still feeding less than 4lbs an hour - 40 lb bag of pellets lasts more than 12 hours, even when stove is set to an absurdly high room temp (which it never reaches)
 
Please re-read my post. I am suspicious that you have a weak vacuum switch which can give you this symptom.
SMK
 
stovemanken said:
Regarding the original post:

As suggested, put the feed rate on 6 and the stove in STOVE TEMP on 7. Let the stove burn for 30-45 minutes. Leave the control door open so you can see the lights on the board. With these settings, you should be in virtually continuous feed. That means the FEED MOTOR light should be glowing all the time. If it is not, then you have a draft problem that is causing the draft differential swich (vacuum switch) to intermittantly open and close, leading to irregular feed. Let me know what you find.

SMK

I tried that - the stove feeds for between 15 -40 seconds out of every minute.
the flames are pretty energetic, so I think the draft is good.

If the Vacuum switch is bad, what is the solution? can it be replaced independantly, or do I need a new controller board?
 
With the controls set as described, the feed should be constant. The fact that is not is the reason that you are only feeding a 4/lbs/hour. The vacuum switch is a very simple replcement. Please be aware that there is a known issue on Accentra Inserts with vacuum switches that are identified with a yellow part number tag. You need one with a green part number tag. This is due to the longer distance the vac switch is from the intake plenum on the AccIns.

Also, the next time you run low on pellets in the hopper, scoop the rest of them out and check out the slide plate. Your owner's manual describes cleaning the fines out of the feeder periodically. The slide plate lives above that clean out area. You may have to jog the feed motor to get it to a point where you can pull the slide plate out. I want you to look for 2 things: 1) excessive fines trhat can build up in the slide plate area, particularly in the area where it goes "home" meaning where it is at its farthest point of travel. 2) makes sure the slide plate is in one piece. Very rarely the welds can fail and you end up with 2 slide plates and the fines build up between the pieces and cause your symptom.
 
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