CO detector has gone off twice!

[Fish MT]

I am a new pellet stove owner (Enviro, Meridian). I have been using the stove regularly since mid October and following the cleaning/maintenance program that is documented in the manual (with two exceptions). There have been two times that the CO detector has gone off when I was running the unit on 4 (5 max) for most of the day and probably let the cleaning of the burn pot go a day to long. Luckily nobody was home either time, but this seems to be an issue. I have two young children and know that even low levels of CO can be harmful over long exposure.

The first time it happened I call the fire department and they came over and did not find any significant levels of CO in the house (all less than 5%). However, I had shut down the stove when I got home and noticed the detector going off but did not vent the house because I wanted to know if it was actual detection of a false alarm.

Could these two alarms be from my poor judgment on when to clean the stove or if there might be something wrong with the stove install? I am now cleaning my stove on a daily basis when I am running the stove above 3 and every other day other than that. This seems to be working but want to make sure I am not getting low levels of CO. I have access to a calibrated CO detector that will give me % readings but not for a couple of weeks. Please give me any advise on what to do.

 

[MountainStoveGuy]

i have never heard of a pellet stove emmiting CO from the actual unit..

How is the stove installed? is the vent close to a ventalated sofit?

 

[Fish MT]

i have never heard of a pellet stove emmiting CO from the actual unit..

How is the stove installed? is the vent close to a ventalated sofit?

A ventalated sofit is located directly behind the stove. It is not piped directly to the stove but it is within three feet of the stove. Installers said it would be a waste of money to pipe it directly.

 

[MountainStoveGuy]

read page 8.

(broken link removed to http://www.duravent.com/docs/instruct/L502_aug05.pdf)

 

[Fish MT]

Okay I might be a little slow here but just want to confirm. It looks as if I could be pulling CO from the outside through the sofit.

Now you get to know how little I know. My unit is vented directley to my chimney. So I went to inspect what the chimney looked like out side and found that the bottom of the chimney was open. Is this normal, seems like this could be a hazard with wood stove (former use of chimney).

 

[MountainStoveGuy]

wait, i thought you were vented close to a ventalated sofit, your stove is hooked up to a existing chimney? Is there a block off plate? Do you smell any smoke when the CO dectectors are going off? If you vent to close to a ventalated sofit the house can draw up CO and bring it into the house. Any chance you can post some photos of the install?

 

[MountainStoveGuy]

just to confirm we are on the same page. a ventalated soffit is the venting underneeth the roof eaves...

 

[begreen]

Sounds a bit confused with the terms. Perhaps it's OAK is under the soffit. It sounds like it's venting into an existing fireplace chimney, is that right? If the stove is venting into a chimney with no block off plate, could the chimney be back-drafting on a cold day?

 

[Fish MT]

Yes, I am a little confused. I'm not great with building terminology, Sorry. Below is a description of my install I will try to put some actual pictures in when I get a chance.

My stove is vented directly to my chimney with approximately 2 feet of the pellet stove 4" vent pipe sticking into the 8" Chimney. The vent pipe is at approximately 45-degree angle to get to the Chimney inlet. The chimney is lined but I am not sure of the specs. As I said before the bottom of the chimney is open. I have attached a rough drawing of the install that is not to scale by any means.

I have a fresh air vent directly behind my stove, and it pulls air from the same side the chimney is on and is approximately 4-6 feet away from the chimney.

I have never smelt smoke in the house and the vent pipe does not seem to leak. I clean the vent pipe every ton of pellets due to the 45-degree angle.

That is everything I know as of now but will send more details if need when I get home tonight if needed.

 

[GVA]

So the chimney outside is bottomless
the Outside air is 4-6 feet from the chimney

Was the chimney lined all the way or is the pipe just go into the chimney for a couple of feet?

Does the chimney have multiple flues?

Is there anything else on that flue like a fireplace upstairs?

Where are the CO detectors located that are going off?

 

[Fish MT]

So the chimney outside is bottomless
the Outside air is 4-6 feet from the chimney

Was the chimney lined all the way or is the pipe just go into the chimney for a couple of feet?

Does the chimney have multiple flues?

Is there anything else on that flue like a fireplace upstairs?

Where are the CO detectors located that are going off?

Yes chimney outside is bottomless and outside air is 4-6 feet from chimney.

The chimney is lined with an 8" (diameter is what I think it is not sure though) liner all the way up. The stoves vent pipe sticks into the 8" inlet to the chimney and does not go into the vertical flue. It is a duel flue chimney other flue is used for fireplace upstairs. The CO detector is located in the basement in the same room of the stove.

Thank you all for your patience in understanding my post. I will someday be able to make my post a little more clear.

 

[GVA]

How exactly is the 4" vent connected to the 8" pipe
are all joints in the 4" pipe sealed properly?
Do you have a gas water heater or any other fuel fired appliance in the basement?


Where are you located? recent weather? was it really cold on the days the CO detectors went off.
The bottomless chimney sounds like there may be a TEE at the bottom with a cleanout possibly, But on cold days will keep the liner cool.
like on a woodstove draft is important and a cold chimney will affect that... Even though it is a power vented stove the chimney should help not hinder this.
Does this stove start by itself?
I'm leaning towards vent pipe problems here at at least one connection.
If i'm throwing too much stuff at you just let me know?

Pictures too... Like the saying goes they are worth a thousand words

Hey guys who's the Enviro guy here? >:-(

 

[HarryBack]

looks like a steel cimney to me.......Im guessing the plug to the bottom of the tee is missing. Maybe some gas getting sucked back in thru a window or around the wall thimble..also possibly a leak. Get another CO detector, use it as a check....if they both go off, shut that thing down and figure out wahts going on. Self-install or dealer?

 

[elkimmeg]

My geuss since it is in the cellar and being vented into a masonry chimney is that there are other fuel burning appliances is furnace hotwater heater possibly a clothes dryer there
If the pellet stove is venting into that chimney and a furnace oand hot water heater the location of all fuel burning appliancee and in close proximity and all vying for the same imediate vollume of combustion air Even with the outside air kit is it blocked? Is it possible another appliance is setting off the co detector? we need much more detail of your chimney setup and what else is connected to it and their location in relationship of each other is a dryer also in that basement?

 

[Fish MT]

Okay now I have some pics. But first a few questions to answer. Live in Montana, weather was cold (high of -5 F) the first time CO detector alarm went off not as cold second time but probably in the teens. There are other gas appliances and dryer in the basement but the dryer was not on either day, and the gas hot water heater is in a seperate room that is attached to the garage with good cold air available. The chimney is steel and yes the plug at the bottom is missing (is that a problem?). Professional install.

Now the pics. First just a pic of the unit itself and the vent pipe inside.
Second close up of wall thimble

More to come

 

[Fish MT]

More Pics

Chimney outside can see the Tee out let on top of pic

Pic inside chimney Tee with view of stove vent

Any other pics that could be useful?

 

[berlin]

i'm not completely sure what i'm looking at in the right-hand picture, however if you have a cap missing from the clean-out T, i would say that yeah, that's where you need to start; PLUG IT NOW.

 

[begreen]

Good info Fish. You're doing great. Get a proper endcap installed on the bottom of the 8" stack. That's step one.

However, at this point, I still don't see the connection to the CO alarm going off. Does the stove have an outside fresh air intake system installed? This would be a separate pipe that delivers fresh combustion air to the stove.

 

[Fish MT]

Thanks everyone for your help this is a great site a novice like me couldn't ask for anything more. I am going to get a new plug for the T in the chimney and also a secondary CO alarm. If they go off again I am going to get the dealer back to the house to check the seals around the stove vent.

Does the stove have an outside fresh air intake system installed?

The dealer did not install the outside fresh air kit because I have a outside air vent that is positioned directly behind the stove. You can see just a sliver of the vent cover in the picture of the front view of the stove right side of stove. I think I will pipe it directly to the stove. Thanks again for all of the advice.

 

[GVA]

Thanks everyone for your help this is a great site a novice like me couldn't ask for anything more. I am going to get a new plug for the T in the chimney and also a secondary CO alarm. If they go off again I am going to get the dealer back to the house to check the seals around the stove vent.

Does the stove have an outside fresh air intake system installed?

The dealer did not install the outside fresh air kit because I have a outside air vent that is positioned directly behind the stove. You can see just a sliver of the vent cover in the picture of the front view of the stove right side of stove. I think I will pipe it directly to the stove. Thanks again for all of the advice.

Herein lies the problem:
First clean that pipe...... then put the cleanout cover on it.
Second you have a pressure vented stove which means that most likely the exhaust is blowing out that cleanout and not going up the pipe.
Third the fresh air intake setup that is there is allowing that exhaust right back into the basement. (how close is this to the pipe outside?)
fourth it doesn't look like the joints on the pipe inside the house are sealed. Seal them up.
and last Good luck and keep us informed.

 

[Fish MT]

Thanks for the details GVA

So I sealed the thimble with high temperature silicon. I went to the dealerto get a plug and they said all I need is a 12" slip cap and screw it into the 11" outer pipe. The T is a 8x11" insulated T. This seemed a little weird to me I asked a couple of times to see if I wanted one to seal better. Do you think the 12" slip cap will work or should I get the actual plug that goes with the T? What is the best way to clean out the vent, vaccumn? Thanks again

 

[Gooserider]

Was that chimney CLEANED before you had the pellet stove put in? It looks pretty cruddy, definitely needs a sweeping.

I agree on the need for a cap, it would look to me like the smoke from the stove is probably going out the bottom instead of up the chimney like it should.

The other thing I'd consider is trying to get that 4" pipe from the stove extended just a little so that it's end is about even with the inside end of the "T" and if possible fill the rest of that void around the 4" pipe with something to keep the smoke from trying to travel back down the outside of the 4" pipe and into the house. Figure out where you want the smoke to go, and block all the other alternatives is the basic idea.

Gooserider

 

[begreen]

Thanks everyone for your help this is a great site a novice like me couldn't ask for anything more. I am going to get a new plug for the T in the chimney and also a secondary CO alarm. If they go off again I am going to get the dealer back to the house to check the seals around the stove vent.

Does the stove have an outside fresh air intake system installed?

The dealer did not install the outside fresh air kit because I have a outside air vent that is positioned directly behind the stove. You can see just a sliver of the vent cover in the picture of the front view of the stove right side of stove. I think I will pipe it directly to the stove. Thanks again for all of the advice.

Ah, that was the missing clue. I didn't know there was an air vent sitting below the open stove pipe. There's the problem. Cap the pie and it should be much better, (as long as no one parks a car outside the vent and leaves it running).

 

[GVA]

Thanks for the details GVA

So I sealed the thimble with high temperature silicon. I went to the dealerto get a plug and they said all I need is a 12" slip cap and screw it into the 11" outer pipe. The T is a 8x11" insulated T. This seemed a little weird to me I asked a couple of times to see if I wanted one to seal better. Do you think the 12" slip cap will work or should I get the actual plug that goes with the T? What is the best way to clean out the vent, vaccumn? Thanks again

I'm not the person to ask about cleanouts on stove pipe there are others here that know far more than me on that side.....(but I would go with the cap that fits the cleanout)
As far as cleaning the pellet pipe You can get a nylon bristle brush and most of it comes right out and a shop vac to suck up the dust.
The pipe inside the house.......... the pics showed no sign of sealant at each joint....... not just the thimble those elbows for example can leak, and every joint before and after should have the hi-temp silicone applied probably clear in your case....... If you need to have a disconnect, a portion of the pipe can be taped with a high temp foil tape for ease of disassembly just make sure you use the right tape....
And just for the heck of it go to your hot water heater and at the draft hood strike a match and see if the flame gets drawn towards the hood and not away from it.

 

[GVA]

Are ya still there Fish MT? :-/