Pellets piling up in firepot below 10ºF.. Tired of it!

[Bobcat698]

I have an http://www.americanenergysystems.com/ Magnum Countryside pellet stove.. 50k ish BTU rating.
It has 5 settings, 1 through 5.
The chimney exits out the bottom floor of my bi-level home out the western facing wall. I have tried with a cap and deflector straight out, as well as with a 90 degree elbow facing south at about a 45 degree angle (per my local stove dealer's suggestion). There is a fresh air inlet pulling air from outside, and the damper works off the furnace blower.. you regulate how fast the air moves out of the stove, adjustable manually.
The chimney exit is 68 inches above grade. There is a 52 inch vertical chimney section, indoors, and a 24 inch horizontal run. 2 90's are in the chimney. A T-90 at the bottom and a 90 to go out through the wall.

It seems that no matter what I do, or whatever pellet fuel I try, I cannot burn the stove at 3 or higher when the temperature is below 10 degrees. I can completely clean the stove top to bottom in the afternoon, set the heat on level 3, and within 6 hours or so the fire pot is full/overflowing. You can turn it down to 1, scoop out some of the excess pellets, and it'll eventually clean out, but as soon as you turn it back up, and the temp is below 10 degrees, the same crap will happen. I've tried running the draft all the way open, half way open, all the way down to nearly closed (like the manual recommends, once you get the flame how you want it)

I have done the following troubleshooting:
Auger motor (obviously not related, but it failed)
Replaced Exhaust fan with a high-output fan (from AES)
Cleaned the stove (several times, with a leaf blow, air compressor, etc)
Replaced the fire pot (was hoping there was a revision)
Disassembled everything that can be taken apart and cleaned
Changed the vent cap to a different style
Put in a fresh air vent (in case of "negative pressure")
Cleaned the chimney

I've attached 2 pictures of the stove. (yes, the propane cylinder next to the stove is legit)

Can anyone offer any input? What am I doing wrong? I've gone back and forth with AES for advice.. Nothing changes this issue.
I'm ready to sell this stove.. I'm sick and tired of not being able to turn it up when I REALLY need heat. Sure it works good above 10 degrees but it goes below 10 for sometimes a week at a time or longer here.

Thanks for any input!

 

[johneh]

Does the stove have a manual draft control if so open it up a bit
sounds like lack of combustion air at higher pellet flow ( auger cycling faster )
putting more fuel in the burn pot

 

[Bioburner]

How old of stove? I am thinking bad gaskets in doors if more than 5 years old. I have serviced many and am getting ready to sell one I had as a backup. I hated the hidden passages.

 

[Bobcat698]

Does the stove have a manual draft control if so open it up a bit
sounds like lack of combustion air at higher pellet flow ( auger cycling faster )
putting more fuel in the burn pot

Yes. I've tried it wide open.

BTW the chimney is 3 inch.

 

[BobMA]

Might need to think about 4" pipe......elbows count as "5", each one foot vertical counts as "0.5", each one foot of horizontal counts as "1".... If total value exceeds 15 then recommendation is to go to 4" pipe....what is the diameter of outside air?... With my stove, any run longer than 6' , manufacturer recommends 3" OAK.....your manual might have some recommendations on what I've mentioned above

 

[Bobcat698]

By your numbers it adds up to just over 14. The oak is 3 inch.

 

[BobMA]

Sorry, just went back and calculated, thought your reference to 45 degrees was a pipe fitting that was installed....you have 2 - 90's = 10, 52" vertical = roughly 2.2 and 24" of horizontal = 2, so your under the "15"...would think your okay.....guess I'd still stick with outside air recommendation ..... Any chance of an obstruction anywhere?

 

[Bobcat698]

I stand corrected.. I do have a 90 degree elbow pointing at South outside angled at a 45 towards the ground.
I guess I have had that elbow on for a couple years.. With that 90 factored in I'm over the 15 recommendation.. Is it generally OK to vent to the west, wind wise?

 

[Don2222]

Hello

The stove not working on heat level 3 when the outside temperature is 10 degrees or less is preventing the proper air/fuel mixture for complete combustion in that stove. I have tried Direct Temp vennting that warms the burn air but those stoves are not made to work with it. Therefore the best option is to trade the stove.

 

[BobMA]

My vent has a cap on end that looks kind of like a dryer vent without the flapper (dura vent) and mine faces east, so I honestly don't know....perhaps try and remove the elbow when you have the issue, wish I knew a way to simulate 10*F

 

[yrock87]

I would recommend dropping the outside air kit to see what happens. Pulling in extra cold air does not improve combustion, it reduces it in pellet stove because you are now having to use btus to heat up combustion air in order for the fuel to burn properly. Living in Fairbanks I was advised not to add an outside air kit for this reason.

 

[Mt Bob]

So you have been in touch with the dealer that sold you the stove?Or is this another bought it from the tractor supply store?Who installed it?

 

[johninwi]

Whats the history of the problem?
Guessing you've had the stove a while and this is a somewhat recent change?

Put in a fresh air vent (in case of "negative pressure")

So the problem existed before having the outside air vent?

 

[DBCOOPER]

I would recommend dropping the outside air kit to see what happens. Pulling in extra cold air does not improve combustion, it reduces it in pellet stove because you are now having to use btus to heat up combustion air in order for the fuel to burn properly. Living in Fairbanks I was advised not to add an outside air kit for this reason.

Where do you think the air comes from when you don't have an outside air kit?

 

[doghouse]

Pre-heating air for use in an 1100 degree fire. OK.

 

[yrock87]

Where do you think the air comes from when you don't have an outside air kit?

Obviously it comes from the hotel envelope of the house. And yes cold outside air will "leaks" it's way in somehow or negative pressure will develop. I have a tight house, but as an outside air kit was not advised, I leave an outside air vent in the room with the stove open. Combustion air is preheated from the house envelope and is replaced in the heated room minimizing drafts.

The reason they say that the direct outside air can be a problem in very cold temps (and this situation may or may not be caused by this) is because when you have sub zero air coming into a stove directly into the Pellets you are trying to bring that 0 air up in temp an extra 70 or so degrees in order to reach a high, clean burn temp. Let's say your exhaust temps are 300*, and that is where your stove is happy at. If you pull in 70 or 60 degree air, it heats up 240 by the combustion of Pellets. But if your outside air is MUCH colder, let's just say a nice Arctic - 30, you are now asking your stove to heat air 330 degrees to reach that nice happy temp. An extra 100 degrees of heating for 150 cfm of combustion air is no chump change.
If you have an esp like a Harmon it can cause significant overfeeding of Pellets just to keep the exhaust temps up, I don't know what the specific results would be with a stove that does not adjust feed rates, maybe Pellets would just pile up because they can not burn adequately.

I do see that the op installed outside air in an attempt to fix the problem, missed that last time.

 

[Bobcat698]

Ok, to clear up a few things;
The stove came with the house, I didn't buy it.
The outside air kit has been installed since I've had the house/stove in 2009.

The "make up" air kit is model 216, here.
http://www.skuttle.com/aircontrols.html
Pretty much the best way to waste $1250.. (had someone else install it)
It only brings in fresh air when the furnace runs... Which if the pellet stove is working, doesn't need to run.

I installed the skuttle in fall of 2011. Made no difference in the cold temperatures.

I am quite curious about trying to unhook the outside air kit.. It would make sense and maybe even heat slightly better since the air coming into combustion chamber would be 70 degrees+ warmer.. But cooler air is denser..

 

[SmokeyTheBear]

Ok, to clear up a few things;
The stove came with the house, I didn't buy it.
The outside air kit has been installed since I've had the house/stove in 2009.

The "make up" air kit is model 216, here.
http://www.skuttle.com/aircontrols.html
Pretty much the best way to waste $1250.. (had someone else install it)
It only brings in fresh air when the furnace runs... Which if the pellet stove is working, doesn't need to run.

I installed the skuttle in fall of 2011. Made no difference in the cold temperatures.

I am quite curious about trying to unhook the outside air kit.. It would make sense and maybe even heat slightly better since the air coming into combustion chamber would be 70 degrees+ warmer.. But cooler air is denser..

Get an air compressor and get all of the crud out of the small bendy place in the exhaust channels inside that Countryside, maybe a leaf-blower on vacuum can do the job.

Don can tell you where they are and how to get to them. He can also tell you about a high CFM combustion blower for that stove.

 

[Bioburner]

Cheap coat hanger and get into the wall behind the fire brick by going up thru the ash bin. Can give that panel behind the brick a few good thumps to help shake out those hidden passages too. PIA

 

[daffonce]

if pellets are building up it seems like you aren't getting enough combustion air, or your feed rate is too high. seems like people are saying the stove you have has hiden exhaust passages, i would start there, if they are plugged your exhaust blower will pull less air through burn pot causing less burn. the door gasket is another good idea, read up on the dollar bill test. if it is leaking and the hiden passages are blocked your exhaust blower will pull air through the leaky door gasket instead of through the burn pot, meaning you won't be burning pellets. also i would think that you might want to try the 4" exhaust, it is less restrictive and would allow exhaust to more freely flow. my bet is combo restrictive exhaust passages and leaky door gasket combo.

 

[Bobcat698]

I have installed the high cfm exhaust blower already, last winter. No change.

I've replaced the door gasket and I have made sure to do the dollar bill/paper test. It's tight.

Trust me, I've used a leaf blower and an air compressor.. I was so sick of the bs that I drug it outside at 5 degrees one morning and did it again. I know where the hidden passages are.. I've even rigged up a flexible clear hose to my vacumn to get in there real deep like.

Thanks for all the feedback thus far!

 

[SmokeyTheBear]

Now since you tell us that you did all of that, please post a picture of your burn pot and tell us exactly how well it sits in its cradle.

Air coming into the stove should pass through the pellet pile if it goes around the pellet pile you are fighting a head wind.

 

[Bobcat698]

Do you mean a head wind on the cold air side, or on the exhaust side?

 

[SmokeyTheBear]

Do you mean a head wind on the cold air side, or on the exhaust side?

No if the combustion air is going around instead of through the pellet pile the fire isn't getting enough air, this situation is a combustion air bypass and is exactly the same as not enough air. But since you brought up air against the vent system (both the exhaust and the intake comprise the vent system) I'll just say you should never vent into the prevailing wind and your OAK and Exhaust should be on the same wall. Back pressure caused by venting into the wind reduces the air flow through the stove. You also should not have any downward sections in your exhaust (you appear to be close to the 4" break point) down sloping exhaust systems also restrict airflow.

 

[hoverwheel]

Last winter I had a new pellet stove that would build up a big pile of unburned pellets and choke. In the spring I took it outdoors and used a leaf blower to super clean everything.

It took an hour and unreal amounts of billowing ash, but it ran like new again.

Will need to clean it more and deeper this winter.

Pellet stoves want to be clean as a whistle.