Lopi 380 draft issue...

Hi guys!

I had an issue last night with an older stove I've been using the last several years. It's an older Lopi 380, precursor to the Lopi Endeavor of today. It has early secondary burn features, but nothing like what is required by the EPA to-day. I've been burning wood in this model Lopi for at least 10-12 years, never any problems with draft or smoke in the house, except the occasional start-up when it's really cold outside and the stove pipe and steel liner in the chase is super cold.

Well, it's in the '20's and teens right now here in Seattle area, and I had the stove burning all day yesterday, just like normal, very pleasant, maintaining a comfortable heat in the house. Well, around nine o'clock last night, I went to put a couple more pieces of wood in the stove, no issues, but 1-2 minutes after I shut the stove doors and sat down, I started smelling smoke. I went to investigate and couldn't find anything suspicious. I had the secondary burn damper over top the front doors fully open, but couldn't see any smoke coming out. Temperature gauge was reading about 450 degrees Fahrenheit. The smoke smell never went away, stayed all night until I let the fire burn out, it was bothering my wife and daughter, definitely irritating my sinus too.

I thought with all the heavy snow, maybe the top of the chimney was becoming partially blocked by snow somehow, we dont usually get this much up here 8-10". I went outside last night to check, and it didn't appear any snow had formed around the chimney top.

I'm wondering if the up draft was lost some-how when I added wood late at night...if that's possible? Maybe because it was so cold, and my fire wasn't burning hot enough....but even with the start-up damper fully open and the fire really going, it still smelled like smoke. I've got double walled stove pipe from the stove to the entry point in the wall, and stainless steel liner all the way up through a tall chase.

I clean the stove and piping, and chimney liner every other year, usually only burn maybe a cord-and-a-half or two of wood a season. Never any heavy creosote build up, minimal powdery black along the walls. I have some pine that a friend gave me.....I know...PINE....nasty stuff....but I only use it for start-up, and it's been dried by me for 3 years. I switch over to 2-3 year seasoned maple after its warmed up.

i've included some photos to kind of show my set-up. Tall chase on the right is the one the stove is hooked to. I'd appreciate any advice...if we loose power in this storm, I need this stove working.

Thanks very much,

Dow

begreen said:

Is there a screen at the top of the chimney? If so, it should be checked for plugging.

That is quite a long horizontal run. Pull the stove pipe and check for creosote buildup in the horizontal section. For better drafting consider shortening the stove pipe coming off the stove and connecting that with an elbow to create a simple offset angled directly to an elbow in the wall thimble.

How much snow did you end up getting?

Click to expand...

Thanks,

I pulled the stove piping, and like you suggested, the elbows and horizontals had probably 1/4" of silty/powdery creosote build up...no hard crisp stuff. I cleaned it all out with a brush, put it back to-gether, and it's working just fine now. We ended up loosing power for a day, so it was nice to have the stove going.

Here in Maple Valley we got around 2 feet of snow. Worst weather driving conditions I've ever been in. We still have a ton of snow...my wife got stuck yesterday at the end of the driveway while I was traveling for work.

Thanks again for the advice.

Dow

This photo is of the thimble.

begreen said:

Good to hear that it is working again. The horiz. run combined with the 90º turn at the end is slowing down draft too much. Changing this to an offset with an angle should cure the problem and it will help the stove run better in milder temp weather.

Yes, I've done a lot of snow driving and this stuff was bad. As it warms up driving in it is like driving in a foot of mud. Feels like there are ball bearings under the tires. Fortunately our roads and drive are now finally clear.

Click to expand...

Could you give me some sort of photo example of the set-up your talking about for better draft. I'm trying to picture in my head what you mean...just want to be sure I'm on the same page as you.

Thanks,

Dow

Man....a week later and the same problems occurs tonight.

It’s been working fine and all of a sudden it dips down below freezing again and the the house is smelling like smoke. I can’t see where any smoke is coming out of the stove. Where would it...the upper secondary damper, or the lower start-up dampers?

This piping is expensive, not too thrilled about having to buy some more. But I guess I seriously need to. So two 45 degree bends with vertical and horizontal offset going to the 90 coming out of the back of the thimble is better than the current set up: a long stretch out the top of the stove to a 90, then 45, to the thimble and another 90?

I can’t run this stove in it’s current state, my girls are coughing. Very irritating.

Thanks for the help!

Dow

Thanks for all the replies guys! I haven’t been able to access the cap, too much snow on the roof still...I could easily slip and fall off/ break my neck. I’ll just have to wait until it’s safe to access.

I was able to clean out the soot at the bottom of the chase when I took the stove pipe apart.

Ya...run it with this pipe setup the last several years, and never an issue with configuration. Hoping it’s just dirty cap.

I’ll keep you all posted!

Dow

Well...shoveled enough snow off the roof so I could access the chimney. I pulled and inspected the cap, wasn’t hardly dirty at all, minor build up, and it’s not a mesh screen cap, it’s very open, I didn’t see anything that indicated a blockage of any type. And the pipe leading to the cap had minimal powdery build up along the walls, nothing to restrict flow.

Guess it’s got to be something to do with the stove pipe setup and temperatures in the high teens and low 20’s messing with the draft. This only happens late at night, when it’s really cold just before bedtime, after I’ve had the stove going all day without issue.

I’m trying to re-strange the piping, and this thimble sticks out awfully far from the wall, 10”. I need to cut down that horizontal flow path, can I just cut this thimble in half myself to reduce length, or should I buy a new one?

Thanks,

Dow

Here’s some pics of the horizontal piping, and the thimble.

Dow

And here’s how I’ve arranged the pipe I currently have and was previously using. I’ve got to go get another 45 degree connection, and may need to adjust the stove some. Does this setup look a little better? Nothing is attached, just in position for effect.

Dow

begreen said:

Yes, that will be better, but it looks like the vertical pipe coming off the stove needs to be taller.

Click to expand...

The 45 degree offset pipe sticking out is telescoping, it’s got a lot more room to extend. I was going to cut the thimble, move the stove forward another 6” and install another 45 elbow on the modified thimble, should line up ok.

Does the vertical pipe coming out the top of the stove need to be taller for better flow?

Thanks,

Dow

begreen said:

No, just for alignment.

What does the thimble connect into? 6" tee and chimney pipe?

Click to expand...

Correct. Thimble just screws into a receptacle flush with the wall, and that is connected to the 6” tee that is connected to the chimney pipe. I’m thinking I can just cut/shorten the pipe on the thimble, to leave enough for maybe 5” and a 45 to come off of it.

Dow

Thimble...

Nothing permanent...but after a trip to town and an extra piece of pipe, and another 45 elbow...this is what I’ve got.

I only wonder if I ought to remove the 5” in between the 45 and thimble...the only horizontal on here now? I just don’t want the pipe being too close to the wall without the 5” piece of pipe. It’s double wall rated for 6” away from drywall, but....I’m not crazy about hot pipes and drywall. But hey....got rid of a 90 degree elbow and a foot of horizontal pipe

The man at the stove shop was thinking maybe the issue could be that after burning all day, and late at night...my house could be starving for air, and my stove also, even with dampers open. Something about a negative pressure where the stove is burning low enough to be overcome by cold outside air pressure, and my house is using it as an inlet, smoke and all. He agreed that a better stove pipe setup would help the stove run better.

Thanks,

Dow