Boil in flue pan is off - stack or other fire issue?

[tgormley358]

Something new - my 5th year using my Lapierre Jr 2x5 setup with 5” raised flues and 18x24 syrup pan. I noticed the boil in the flue pan is just way low compared to usual. And wood isn’t burning nearly as fast. When I open the fire box feed doors, flame is shooting out rather than going up the flues and up the stack. This is new to me. Where should I be looking for a problem? I don’t have a therm on my stack. Front pan is boiling well, normal I’d say. I opened up the air a little more at the bottom which usually increases the rear pan boil, but see no change.

[chep]

Check for mouse nests in base stack. Thats experience speaking

[tgormley358]

Check for mouse nests in base stack. Thats experience speaking

Toasted mouse, anyone? This started 2 hours into my nights boil. I boiled 6 hours yesterday. I’m guessing something is stuck in the stack but I’m going to have to take a look tomorrow. Hoping this isn’t a fire hazard this evening but will keep a close eye on it.

[tgormley358]

More mystery - any takers? The barely boiling state continues for about 90 minutes, then on one wood feed the boil came back almost to normal, for around 45 minutes. I thought whatever was stuck in the stack must have burned off. Then it slowed again for the rest of the night. A mouse nest would have friend along time earlier. Tomorrow I’ll take it apart and see if I can figure it out.

[ecolbeck]

Is there a damper in your stack? Chimney cap closed? Is your stack well above the height of your roof ridge? Perhaps last night's wind caused back drafting?

[tgormley358]

Is there a damper in your stack? Chimney cap closed? Is your stack well above the height of your roof ridge? Perhaps last night's wind caused back drafting?

Thanks ecolbeck. Yes on the damper and yes I’ve given that a look last night. Thing is, I haven’t touched in 5 years so I’m doubting it’s the issue, but still will look again at it tonite. In fact, on my very first boil with it 5 years ago, I had a damper issue and a lot of smoke in the sugar shack, similar to last night. Chimney cap - yes I have one and will take a look later. I also thought about the wind last night, especially as the issue wasn’t constant - started find for 2 hours, then the problem started, then the boil came back, and then the issuer returned, but not as bad. At one point there was actually smoke collecting just below the flue pan. I took video of it.

[maple flats]

On a wood burning evaporator you should have NO damper. It needs the full draft and that makes the wood burn full potential. Until you can remove the damper, make sure it is still attached to the handle and not able to turn out of alignment with the damper handle, then wire the handle to face straight vertical. Next, give the fire as much air as it needs to roar, your boil will thank you for it.
An evaporator is nothing like a wood stove in your home where you need control of the exhaust.

[tgormley358]

Chep had it right. I took the pan off the arch today and sure enough a big nest in the base stack. They pulled out a lot of fiberglass insulation and dragged it in there. A pail full. I even reached up vertically into the stack to see if there was more and there was a bit more. Busy little beavers.

Unfortunately this wasn’t the end of it. I started a small fire and it’s still not drafting. They must have more nest further up the stack. Tomorrow I’ll go back at it. I laid a couple of mouse traps tonite. I’ve got to keep them from going back in there. The only way in I can see is thru the air vent below the fire box. I closed that tight tonite.

[tgormley358]

On a wood burning evaporator you should have NO damper. It needs the full draft and that makes the wood burn full potential. Until you can remove the damper, make sure it is still attached to the handle and not able to turn out of alignment with the damper handle, then wire the handle to face straight vertical. Next, give the fire as much air as it needs to roar, your boil will thank you for it.
An evaporator is nothing like a wood stove in your home where you need control of the exhaust.

Thanks Dave. I’ll also check the damper when I look up the stack tomorrrow. Lapierre shipped it with the damper, not sure why.

[chep]

Im glad you found it! I did the same thing 2 years ago. The flames comin out the firebox was the clue that tipped me off. Now i check very well before assembling the rig each year

[maple flats]

In all of my years I never had a nest in the stack, is your stack straight up off the arch?
The best mouse trap I've ever run is a bucket of water (or RV antifreeze in cold temps) about 4-5" deep. Set it out of the way. Then place a rod across the top and on the rod have a bottle that can rotate (I used an Orville Redenbacher popcorn jar, it has a deep dimple in the bottom, to drill a hole and a small neck. Then slide it on the rod or dowel, smear a little peanut butter on the outside of the bottle and check for victims every day or 2. I've gotten as many as 12 in 2 days, in my 5th wheel camper when I first tried this method, now, if I need to, I set it up and 1 or 2 nights cand the problem is gone.
I also see an ad running recently for a trash bucket with a flip cover that dumps the mice as soon as they walk on the top, no idea what they cost, but I'll bet it's fool proof, can catch a bunch and less messy.

[motowbrowne]

In all of my years I never had a nest in the stack, is your stack straight up off the arch?
The best mouse trap I've ever run is a bucket of water (or RV antifreeze in cold temps) about 4-5" deep. Set it out of the way. Then place a rod across the top and on the rod have a bottle that can rotate (I used an Orville Redenbacher popcorn jar, it has a deep dimple in the bottom, to drill a hole and a small neck. Then slide it on the rod or dowel, smear a little peanut butter on the outside of the bottle and check for victims every day or 2. I've gotten as many as 12 in 2 days, in my 5th wheel camper when I first tried this method, now, if I need to, I set it up and 1 or 2 nights cand the problem is gone.
I also see an ad running recently for a trash bucket with a flip cover that dumps the mice as soon as they walk on the top, no idea what they cost, but I'll bet it's fool proof, can catch a bunch and less messy.

I call that one the wheel of misfortune.

[tgormley358]

This turned into a bit of a saga, thanks for input and bearing it with me. The mice nesting was the problem, but that caused other problems. After cleaning out the nest last night, and yet I still couldn’t get a draft, with smoke flowing out the front of the firebox, a friend helped me look up the stack tonite. We found no additional nesting, but the fire still wouldn’t draft. ****, I found the problem but removing didn’t fix it. It’s snowing here today so I didn’t want to go up in the roof to look at the cap to see if it was clogged. Eventually that was the only option so I went up, got the cap off, and found the screen very clogged. So my guess is, the mouse nest caused a lower temp dirtier fire, which clogged the cap with soot which hasn’t happened the last 5 years. I cleaned the screen and started a small fire and it roared like normal, finally.

Dave, the damper was open but I’m going to pursue your suggestion to remove it completely.

Tom

[ecolbeck]

Why is there a screen? Is it to prevent sparks?

[tgormley358]

Why is there a screen? Is it to prevent sparks?

Not certain but I think keeping animals out is also a goal

[ecolbeck]

I would consider ditching it, especially if its purpose is unknown

[raptorfan85]

I would remove any obstruction in the pipe... leave it open for the season, nothing will have time to nest in it. After the season put something over the pipe to keep anything out.