Smoke coming out of air intake valve

[msumner7]

I have a US Stove Company Pellet Stove 5510. When I shut the stove off the fan runs for about 30 minutes. Once the stove is completely off I have had smoke coming out of the air intake valve. It is a good amount of smoke, enough to fog up the room. When the stove is on it is fine. Does anyone have any suggestions? I am considering installing a outside air vent so that if the smoke gets backed up, at least it will go outside. Is this a good idea?

 

[mark d fellows]

It sounds to me like you still have some embers that are still smoldering when the combustion fan goes off and you have no vertical rise in your vent pipe creating a draft. I don't know about your stove, is is possible to have it adjusted so the combustion fan runs longer after you shut it off?

My combustion fan probably runs for two hours after I shut if off.

If that happened to me, I would be fixing it right quick.

What would happen if in the middle of the night you lost power and the room filled with smoke? Would you be asphyxiated from the smoke?

good luck.

Mark

 

[kinsmanstoves]

I am with Mark.

What is your venting?

Eric

 

[msumner7]

That sounds like it might be the problem. I just put the vent directly outside. How far should I go up vertically? It
s about 20 feet from the ground right now and the roof is another twenty feet high? Is sending it up about 5 feet enough?

 

[mark d fellows]

That sounds like it might be the problem. I just put the vent directly outside. How far should I go up vertically? It
s about 20 feet from the ground right now and the roof is another twenty feet high? Is sending it up about 5 feet enough?

Ok, from my reading. You need to go up at least 5 feet vertical as heat rises. Then you go out about a foot to get the smoke away from the house and also get the pipe further away from the house to help with draft. Since you already went straight out, you cane put a 90 degree cleanout tee(available at lowes, HD, or Tractor Supply company) and then go up 5 feet verticle and then a 90 degree elbow and out about a foot.

Since you are going to be doing this outside and your vent pipe could be exposed to condensation, you might want to use the silver galvanized pipe. Your call though.

Best by far is if you run it all the way up to your roof and up about a foot or two. Then there is a natural draft as wind blows across your roof. For that though, you need a larger diameter pipe for runs of that length and it is more expensive. This way though you never have to worry about smoke backing up into the house unless the vent pipe gets clogged.

You can go to the below link and download a harman manual and it will go through all the venting options for you. Or just about any stove company has this available. England Stove Works, Enviro, etc. They all say the same thing.

(broken link removed to http://www.harmanstoves.com/support.asp)

Going straight out is the cheapest, but worse by far for draft.

You mentioned an inlet valve. What is that? I know of an inlet port on my stove. Does yours have some sort of valve that is supposed to close off the inlet air, thus sealing it off from the room after 30 minutes?

Please keep us informed.

Mark

 

[mark d fellows]

You know, another thought just occurred to me. England Stove Works says a Outdoor Air Kit(OAK) MUST always be installed. I wonder if that is because their combustion fan, like the one in your stove shuts off so soon?

Did your stove specify a Fresh Air Kit be installed with the stove? If so, maybe this is why.

Installing a fresh air kit and tightly sealing it I think would stop the smoke from backing up into the house. Maybe you want to look at that first. I have heard some bad things about fresh air kits making stoves not burn as hot, but have heard good things about the summers heat, Englanders that do specify an OAK as a MUST.

First step I would think would be to install the fresh air kit.

Next step would be to install the pipe similar to how I described and is described in most manuals.

I don't have time to research the stove and read the manual but I will check into it later. All I found is that Northern Tool sells them and that they get mostly positive but some bad reviews.

If you do have another form of heat, I would run it until you get this problem fixed. It is a major concern to have smoke back up into your house.

Maybe an easy fix, but still a major flaw in the installation that could be fatal.

Again, keep us informed.

Mark

 

[slls]

I think the problem is the fire is still smoldering after the fan is off. I would check to see what is actually burning when the fan is off.

My stove the combustion fan runs for 10 minutes after the pellets stop dropping, all the embers are out within 2-3 minutes and no way would there be smoke after the 10 minute fan run.

 

[msumner7]

My manual states that the outside air intake vent is usually installed in motor homes. I was thinking about installing mine until I was told by a few people that I may just need to send the vent piping up a few feet to make sure the smoke doesn't get backed up. I really don't want to do both procedures because of the cost and the extra hole in my wall. Would you suggest that I try running the vent pipe higher up my outside wall first or install the air intake vent?

 

[mark d fellows]

My manual states that the outside air intake vent is usually installed in motor homes. I was thinking about installing mine until I was told by a few people that I may just need to send the vent piping up a few feet to make sure the smoke doesn't get backed up. I really don't want to do both procedures because of the cost and the extra hole in my wall. Would you suggest that I try running the vent pipe higher up my outside wall first or install the air intake vent?

Tough decision and here is why,

1. With a cold air intake that is sealed properly, you should never get smoke in the house under any circumstance as long as the door to the firebox and the hopper lid are sealed properly in Power outage, stove turned off etc.

2. With a five foot vertical pipe and another 1 to 2 foot section at the top you should get a draft to pull the remaining smoke out.

Even if you run the pipe up for five feet, you may or may not get a draft. If you run it up above the roof, you will definitely get a nice draft.

Is money and issue, or is it time?

Do you have other heating while you are working on it?

I think with an OAK, you are pretty much guaranteed no smoke but then how will the stove burn?

 

[mark d fellows]

I looked on the usstove company website and there isn't a lot of info available.

 

[mark d fellows]

I found this thread about your stove and someone that had the same problem

https://www.hearth.com/talk/threads/31685/

boof wrote "Also, when that pot fills up and you shutdown the stove well lets just say the stove does not give enough time for the ambers to burn out and as part of the shutdown sequence the stove releases some pellets into the burnpot (for the next startup I suspect) but oftern the ambers are still glowing and now you have a smoldering mess and the stove starts smoking. I need to cal US Stove on this to see if there is a timer adjustment for the shutdown mode."

 

[SmokeyTheBear]

There can be smoldering pellets and embers in the ash that can last for a very long time (well after all of your fans are off and the stove is cold). This is one of the reasons you really need to use the proper vacuum cleaner, an ash can with a tight fitting lid, and keep all ash containers well away from anything that can burn.

You need enough vertical piping in the system to allow a natural draft otherwise you may find smoke coming out of the stove whenever power is turned off while the stove is burning.

 

[MCPO]

The pellets in my stove burns for at least 20-30 minutes after shut down and the combustion fan runs even longer.

 

[mark d fellows]

I found this link within the top of the Pellet forum in trouble shooting. This is definitely good practice for stove vent piping.

https://www.hearth.com/talk/threads/13419/

 

[msumner7]

I think I am leaning toward installing the outside air vent because it will guarantee that I will not get smoke in the house even if we lose power, Are there any dangers or concerns I need to know about installing the outside air vent? (besides the risk of having the fire not burn as hot)

 

[mark d fellows]

No dangers at all that I am aware of.

https://www.hearth.com/talk/threads/32448/

Do a search for "fresh air kit" or "Outdoor Air Kit"

Do they make a kit for your stove?

Mark