Over flowing pellets

frugal heater

New Member
Nov 17, 2017
8
New Rochelle
I have a St. Croix Hastings Pellets stove which I have been happily using for around 9-10 years. Over time, I've learned to take it apart and clean it like a pro, which usually solves any problems. This season it's giving me a problem that I can't solve. When it starts up, it feeds way too many pellets into the burn pot. After it runs for a while, the pellets in the burn pot eventually burn down to the right amount. However, as the day goes on it continues to gradually feed too many pellets into the burn pot. Eventually the burn pot over flows, the flame gets tall and lazy, and the glass door gets black. Attached is a picture.

I've tried adjusting the pellet feeding flow using the auger trim button, but that is not working. Anyone have any ideas of what is going on here?
 

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heat seeker

Minister of Fire
Feb 25, 2011
3,111
Northern CT
If your stove is like mine, the trim only affects heat level 1.

I would time the auger on and off cycles, comparing to the times in the manual. If the times are okay, you may have an airflow problem so that the stove isn't burning the pellets fast enough. If the times are not okay, it may be a control problem.

Have you tried resetting the control?
 

fmsm

Minister of Fire
Dec 12, 2011
942
South of Boston MA
Stupid question; Have you changed pellet brands? If the new pellets are smaller you may get more in the burn pot initially.
 

johneh

Minister of Fire
Dec 19, 2009
2,545
Eastern Ontario
Check your combustion air it sounds like to me that your stove is having breathing problems
Air damper control pos moved ? Plugged exhaust (ash)
 
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frugal heater

New Member
Nov 17, 2017
8
New Rochelle
Thanks for everyone's suggestion. The pellets are a high quality. I also reset the control. Don't see any issues with the damper control. I also looked for air leaks. I could not find any leaks, but if anyone has suggestions on how to find air leaks, would love to hear it.

Timing the auger was tricky. Other than the start up, where it loads up the hopper with pellets and few seconds, it usually feeds pellets every 11 seconds. I feel like I've seen it feed pellets quicker than 11 seconds after it has been running for hours.This is when the hopper becomes over-flowed. Unfortunately I need to sit around waiting for that to happen.

The only area I have not cleaned recently is the baffler. Super hard to get that sucker off and back in. Maybe I'll try to clean that tomorrow and see if it helps.

Thinking I may need to call in a professional.
 

heat seeker

Minister of Fire
Feb 25, 2011
3,111
Northern CT
The baffle is easy to remove and replace- once you get the hang of it.

The feed cycle, according to my manual, is 11 1/2 seconds. The heat level is determined by how long during each cycle the auger turns. For instance, on heat level 5, the auger turns 5 seconds every 11 1/2 seconds, or about 50% of the time. The times are in the manual, I believe. So, you need to time how long the auger motor is energized, be it 2 seconds, 4 seconds, whatever, and compare it with the chart of feed times vs. heat level. That determines the feed rate. If the times agree with the manual, the control is good.

If there is a blockage on the intake side of things, such as in the OAK, or in the stove anywhere before the fire chamber, the vacuum sensor will still be satisfied, even though the airflow is below what it should be.

A tip - when you have the baffle out, pull the tube scraper out and use a mirror and flashlight to look down behind the wall. You can visually check to see if there is any blockage back there. You should be able to see all the way to the bottom, and if you shine a light in the ash trap openings, you should see that, too.

The Croix web site has a great cutaway of the innards of the stove. Suggest you take a look at it, it will help you understand how and what to clean.
 
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Nov 6, 2016
119
Wisconsin
Is there a manual feed button on that stove? My afton bay has one. Could be a bad board check your manual feed button push it on and off see if it's stuck in the on position. Or makes any changes when pushing it.
 
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frugal heater

New Member
Nov 17, 2017
8
New Rochelle
Thanks for everyone's help. Spent more time cleaning some areas in the stove. While it's definitely a little better, it's still not running the way it should. In particular, I notice that when the stove shuts down after being used the glass gets dark with ash and the stove does not burn though the pellets in the burn pot. When the stove used to run smoothly, this did not happen.

I'll keep trying to clean it more, but I definitely have not figured this out. The inside of the stove is covered with a dark, hard to remove ash. This was not how it used to burn.
 

jzm2cc

Minister of Fire
Sep 25, 2014
525
Northern Michigan
My St Croix Prescott will fill pot a bit too much during first 5 minutes of starting but never overflows, just large flame at first.

Allowed mine to cool off this weekend to take vacuum to internals along with sucking exhaust with leaf blower. 30 plus bags burned and only a couple holes plugged on burn pot without cleaning except for ash pan dumps . I swear by leaf blower trick to keep these stoves running clean. Yours sounds plugged up, worth trying this method of cleaning.

Some circuit boards can be set to feed less thus burning leaner. But I'd try cleaning exhaust channels first. Good luck.
 

frugal heater

New Member
Nov 17, 2017
8
New Rochelle
Thanks for the advice on the leaf blower trick. Any instructions on how to do that? Also, where are the "exhaust channels?" I think I have cleaned everything, but maybe this is something I missed.
 

bob bare

Minister of Fire
Oct 31, 2013
2,960
park county montana
Really sounds to me like one or both of 2 things,one,your exhaust/flue is dirty,and, 2 being a prescott,the internal channels are partially plugged,so you take the stove outside,beat it with a hammer,while blowing air through the exhaust passages.Not a new thing is a known problem with some st croix stoves.Some stoves collect a buildup,that is not easily cleaned,I think yours is one of them.As far as the leaf blower trick,use the search box,above,but I do not think it will help you,unless you use it while beating on your stove with a mallet.But,if you get the clog cleaned out,you will enjoy the stove running as new.
 

jzm2cc

Minister of Fire
Sep 25, 2014
525
Northern Michigan
Assuming your stove is not full of sticky creosote, you'll probably have good luck starting with a simple exhaust cleaning with a $35 electric leaf blower. This works great on my Prescott.

Open door on cold stove, go outside and remove exhaust cap, place blower suction tube over exh pipe, seal pipe to blower with duct tape, turn on blower until ash stops coming out.

You could try cleaning up ash trap doors at same time and tapping on back wall of fire box with piece if 2x4 with heat shields removed of course.

Beyond this it's into using flexible cable behind burnpot via small holes on either side, and removing each blower if it's all creosote up
 
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frugal heater

New Member
Nov 17, 2017
8
New Rochelle
Latest update. Haven't had the chance to try the leaf blower trick yet. Will certainly try. Unfortunately, last weekend the stove no longer ignite's. During the start up mode it just keeps feeding pellets into the burning pot. I'm going to also see if there are any professional repair men in my area.
 

rickwai

Minister of Fire
Nov 1, 2011
740
ohio
Suck it out with a leaf blower first!! I can about guarantee this will solve your problem. Takes less than 10 minutes. Clean stove interior as best as yo can then leave the door open and tape the suction pipe of leaf blower to you stove exhaust pipe outside and turn leaf blower on.
 

dotman17

Member
Dec 21, 2017
115
Everett, WA
I don't know. There are some good suggestions here but the only time I've ever had a spill over issue is when my igniter couldn't heat the product up to the combustion point. This typically means you have carbon deposits or clinkers in your burn pot that are acting as unwanted insulators. I would scrape your burn pot out and clean your stove. In my Harman, I additionally have to vacuum out the ignition chamber of fly ash and ensure the ignition holes are clear of ash/deposit as well. If you do this, you can burn any fuel you want. The only impact the fuel might have is the amount of carbon deposits or clinkers it leaves behind... but if you keep it clean, it doesn't matter.
 

fmsm

Minister of Fire
Dec 12, 2011
942
South of Boston MA
I would start at the beginning. Take the stove completely apart, clean and reassemble. A few years back I did not seat a plate properly on my P35i and it caused a similar issue. Once triple checking everything I would be inclined to theorize you may have a bad motherboard.