CAB50 stove: starts up then pellets stop feeding

[St_Earl]

i have had one jam at the top end of the auger in nearly four full seasons.

i poked a wire up the drop chute from inside the firebox and that cleared it.
heatilators have an "open" style auger and are very jam resistant.
the bottom end tapers to a point and the auger "floats' a little in the channel.

yep, ash is a whole different and delightful topic.

i prefer light (in weight) fly ash because our stoves are designed to blow the ash out of the burn pot and into the firebox.
the crabbe pellets i still have make a kind of ash plug as they make a heavier ash than my mwp blends. it's not a clinker, but it's not what i really want happening.
right now i am mixing the two until the crabbe are gone.
i much prefer dealing with fly ash than having to use the pull rod a couple times a night.

with just straight mwp blend, the firepot basically never gets dirty and blocked up.
and the ash drawer takes ages to fill up.
i am fine with removing the fly ash a few times a week in between cleanings.
i just scoop it out with a flat piece of sheet metal i have and dump into a metal bucket.

i can do this while i still have coals in the pot, shut the door and resume burning without having to restart the stove.
i do have a pair of leather work gloves dedicated for stove work. it's too hot to do that procedure barehanded.

 

[GLC2005]

i have had one jam at the top end of the auger in nearly four full seasons.

i poked a wire up the drop chute from inside the firebox and that cleared it.
heatilators have an "open" style auger and are very jam resistant.
the bottom end tapers to a point and the auger "floats' a little in the channel.

yep, ash is a whole different and delightful topic.

i prefer light (in weight) fly ash because our stoves are designed to blow the ash out of the burn pot and into the firebox.
the crabbe pellets i still have make a kind of ash plug as they make a heavier ash than my mwp blends. it's not a clinker, but it's not what i really want happening.
right now i am mixing the two until the crabbe are gone.
i much prefer dealing with fly ash than having to use the pull rod a couple times a night.

with just straight mwp blend, the firepot basically never gets dirty and blocked up.
i am fine with removing the fly ash a few times a week in between cleanings.
i just scoop it out with a flat piece of sheet metal i have and dump into a metal bucket.

i can do this while i still have coals in the pot, shut the door and resume burning without having to restart the stove.

 

[GLC2005]

Where do you get your pellets? Mine come from BC...just west of Alberta. The tech said quality control is not standardized: although different pellet companies describe their products similarly, the colour and amount of ash and the size and number of clinkers is quite variable. Maybe you have better regulations re pellet production and quality.

 

[Hdhogger]

I've had the same condition, which is called a misfire. The only time this has happened is when the stove has been off for a long period of time and cools to where the initial pellet drop isn't enough to satisfy the thermocouple. I believe its 5 minutes to reach 175. Your stove is in such a cold environment this could be your problem. What I've done to remedy this is before firing up take a hand full of pellets drop them in the pot then fire up. Although my basement temp never reaches what you have there this could help you get going even if you still have to hit the reset a couple of times.

 

[GLC2005]

Thanks, Hdhogger. So far haven't needed to do the "hand full of pellets" trick but good to know.

This is a real Canuck question but what do you do when the stove reaches the set point? The stove here has reached 60 F once, just as a cold front blew in, so the stove just kept going. I gather most of you down south, heat your rooms, then allow the stove to shut off, then restart in a timely manner.

 

[St_Earl]

i actually prefer to run continuously if possible when it's cold.
if i have to turn the setting down, i'll do that rather than allow everything to cool off.
once the walls and the furniture and all the contents of the house have been warmed up, i'd rather maintain that than cool down and start over.

but if it's mild temps outside, you will save more by running intermittently.
if i can't run on low without getting too warm in the house, then i use the t-stat.

we're heading just a little below 0F tonight. right now stove is on medium and i expect it will just stay there all night.

at some point closer to 10 below i start running it on high for periods and then backing it down to medium.
only a few times has it been cold enough that i ran it on high basically all night.

the more sophisticated stoves will do this for you and keep the room at a chosen temp.
but i'm always home and i never have slept much, so i am the software.

i will add that i spend the winter barefoot and in short sleeve tee shirts.
it's actually a little toasty on this end of the house right now, but instead of switching to low, i put on some shorter pants. but it's still 5F out, so as that drops, the 78 it is now in the stove room will come down a little too.
my den is off the stove room and not quite that warm.

 

[GLC2005]

That's pretty toasty.

So how do you clean out the ash when you run continuously? You must have found some way of minimizing the flame so that you can get at the ash between the pellet chute and the fire pot. That's how this whole thread started: I went through the shut down procedure to clean out the ash around the firepot. Then had trouble getting the pellets to feed continuously when I started the stove up again.

 

[Hdhogger]

Thanks, Hdhogger. So far haven't needed to do the "hand full of pellets" trick but good to know.

This is a real Canuck question but what do you do when the stove reaches the set point? The stove here has reached 60 F once, just as a cold front blew in, so the stove just kept going. I gather most of you down south, heat your rooms, then allow the stove to shut off, then restart in a timely manner.

My stove runs on a T-stat. so it comes on and off as needed. Haven't had any misfires since that one time. But my basement never gets below 69 now and the high is 71 that's when the T-stat. shuts it down.
I also shut it down once a day to clean the pot.

 

[St_Earl]

i have a paint brush with the bristles burnt to nubbs.
i gather the ashes in a pile towards the front and scoop them out with the thin flat bit of sheet metal.
but that's just for in between times when i shut down for a full cleaning. behind the baffles etc...

i still scoop ash first when doing a full cleaning. keeps the shop vac from filling up so fast and also aids in the cool down time.

and i'll reiterate here -

i prefer light (in weight) fly ash because our stoves are designed to blow the ash out of the burn pot and into the firebox.
the crabbe pellets i still have make a kind of ash plug as they make a heavier ash than my mwp blends. it's not a clinker, but it's not what i really want happening.
right now i am mixing the two until the crabbe are gone.
i much prefer dealing with fly ash than having to use the pull rod a couple times a night.

with just straight mwp blend, the firepot basically never gets dirty and blocked up.
and the ash drawer takes ages to fill up.
i am fine with removing the fly ash one or two times a week in between cleanings.

again, while the MWP blend makes a goodly amount of lightweight fly ash, the burn pot stays almost completely free of ash. that's what i care about. it's just a much better burn.
i suppose with a bottom feeder, a heavier ash that stayed in the pot might be preferable, as i think those clear themselves by the ash being pushed out.

 

[GLC2005]

Hdhogger: Never gets below 69F?? No wonder you said we're in a cold environment here. Last night it was felt balmy in the shop at 14 Centigrade.

St_Earl, I still don't get how you use your paint brush. How do you get the flames low enough in the firepot to clean. Do you run at LOW so the flames barely rise out of the firepot?

Have either of you developed a good way to shut off the stove? I open the lid to the hopper to stop the pellet flow. The fan continues to blow but, after a few minutes, I find I can open the glass door without getting smoke into the room. I unplug the stove before I open the door though.

Then I clean inside, empty the firepot, followed by the tray. Then I plug the stove back in.

If all goes well, a blue light flashes twice in the back and the pellets start dropping. The tech said I shouldn't have to press reset...which is what I was doing initially.

 

[St_Earl]

yeah, i just let it die down a little, brush most of the ash to the front of the box and remove it into the metal canister i have. i wear my leather work gloves that are dedicated for stove work, as it's not a job i can do barehanded.
you really don't need to do this.
i could just ignore the ash till a full cleaning. there is an epic thread about two guys seeing whose stove would run the longest without even opening the door. i think someone ran their PS50 nonstop for a month or more. i just like to clear the fly ash away between full cleanings.

it sounds like maybe you don't have a thermostat. (?)
if you do, just bring it down until it clicks off.
that's what i do when i want to shut down for a real cleaning. if i'm just doing a quick ash removal, i open the lid so i can resume without doing a new start up cycle. which is what happens if you use the stat to shut down and then call for heat again by turning it back up.
a thermostat is also a manual on off switch. but only if you want to reinitiate the start cycle with a fresh pellet drop and having the igniter come on again.

if i just do a quick removal, the heat in the stove stays high enough that when i close the lid again, it just keeps feeding pellets.

for a full cleaning, i turn the t-stat off and let the stove cool a while. but after shutdown, when the fans stop, then, with the t-stat still off, if you then unplug and replug in the stove, the exhaust blower will start, but the igniter and auger will stay off. i do this while i'm cleaning so the airborne ash is sucked out by the exhaust blower rather than getting into the house.

 

[GLC2005]

Thanks, that helps a lot. There IS a thermostat but it rarely gets warm enough for it to be of much use - except to turn the stove off and on. That's why I asked what actually happens when the set point is reached...I've never seen that with any regularity.

Part of the issue may be that things cool off so quickly. The stove gets stone cold within a few minutes. I imagine it's easier to restart when it is at room conditions or a little lower than at freezing or below.

 

[GLC2005]

Tried the "St_Earl brush method" for removing ash. Works like a charm. Didn't need to shut the stove off - just opened the hopper lid to put it in pause mode. How long can you leave the lid open in pause mode before the stove shuts off?

Balmy -4 outside so shop is very comfortable 17 Centigrade. Auger/blower is set at MED except to lower the flame when it was moved to LOW

 

[St_Earl]

i guess as long as it takes to drop below minimum running temp.
but i just do a quicky. you want coals still there and hot enough that when you shut the lid and pellets fall, they ignite straight away.

use a metal canister for ashes, of course
that cheapie 4 inch wide paintbrush is really just a paddle at this point.

 

[GLC2005]

i guess as long as it takes to drop below minimum running temp.
but i just do a quicky. you want coals still there and hot enough that when you shut the lid and pellets fall, they ignite straight away.

use a metal canister for ashes, of course
that cheapie 4 inch wide paintbrush is really just a paddle at this point.

 

[GLC2005]

Yes, thanks re "minimum running temperature". Happy (and warm) New Year to you and everyone here.

 

[GLC2005]

Had trouble with the resumption of feeding of the stove again.

Called the dealer a and he came out himself. After call to manufacturer(?), he by passed the vacuum switch. Things seem ok now.

Apparently this happened to another CAB50 recently. Maybe these switches are part of a bad batch....

 

[Hdhogger]

Had trouble with the resumption of feeding of the stove again.

Called the dealer a and he came out himself. After call to manufacturer(?), he by passed the vacuum switch. Things seem ok now.

Apparently this happened to another CAB50 recently. Maybe these switches are part of a bad batch....

Is he going to replace the "bad vacuum switch"?

 

[GLC2005]

Is he going to replace the "bad vacuum switch"?

That's the plan. I'm not even sure why you need one. Apparently, it has something to do with opening the door when there is a fire going - yes?

 

[Hdhogger]

You need your exhaust blower to keep a negative pressure in your firebox to keep the pellets burning at a good consistency. The vacuum switch makes sure this is happening. Once it senses a drop in, or no negative pressure your stove should shut down.

 

[GLC2005]

You need your exhaust blower to keep a negative pressure in your firebox to keep the pellets burning at a good consistency. The vacuum switch makes sure this is happening. Once it senses a drop in, or no negative pressure your stove should shut down.

Thanks. I will see if the flame is more variable now that the switch is by passed...

 

[St_Earl]

it doesn't affect the pressure, it only senses it.
so it's not for flame regulation, but for safety.
for instance, if your venting was blocked, your negative pressure would drop or disappear and the vacuum switch would open and break the circuit to the auger motor and no more pellets would drop.
or if your combustion mtor just crapped out, same thing. if pellets continued to drop, they would overflow because no air flow would cause them to burn at the proper rate, and this could cause a fire to spread to the hopper.

 

[GLC2005]

it doesn't affect the pressure, it only senses it.
so it's not for flame regulation, but for safety.
for instance, if your venting was blocked, your negative pressure would drop or disappear and the vacuum switch would open and break the circuit to the auger motor and no more pellets would drop.
or if your combustion mtor just crapped out, same thing. if pellets continued to drop, they would overflow because no air flow would cause them to burn at the proper rate, and this could cause a fire to spread to the hopper.

Ah. Was there ever a time in stove development when there was no vacuum switch? Do other stoves use any other way to detect these conditions?

 

[SmokeyTheBear]

Ah. Was there ever a time in stove development when there was no vacuum switch? Do other stoves use any other way to detect these conditions?

It is a safety device, in fact it is the most important one. It should be bypassed only as a test. Never run one for heat with that switch bypassed.