Lopi Liberty overnight burn too hot?

[Deppizzymo]

So this is what my flue temps are looking like during my overnight burn. It's a mix of way dead heartwood oak, soft maple and some sycamore. It just seems to burn out of control/into the red no matter how quick I shut it down. Is this too hot? It's a condar probe thermometer. It typically isn't a problem during normal day loads but during the evening loads it just rages and I can't slow it down... I don't know if anyone has any tips to avoid the blaze or if all is well burning this close/slightly into the red (I have heard condar probes sometimes read high...)

 

[begreen]

How tall is the flue system on this stove?
It might be the loading technique combined with small logs. Overall the splits and logs look small in diameter. They will ignite more quickly.

 

[Deppizzymo]

How tall is the flue system on this stove?
It might be the loading technique combined with small logs. Overall the splits and logs look small in diameter. They will ignite more quickly.

It's a combination of a row of logs going N/S then a row going E/W then I stuff the remaining space with what it will fit which is that row of small stuff going N/S you see. Everything below that are larger splits. I have a bunch of long pieces I had cut back when I thought we were getting an outdoor boiler that fell through so I burn them E/W during the overnight burns. Total stovepipe from stove past peak of roof probably 25-30 feet not exactly sure.

 

[begreen]

With that tall of a flue system the stove probably needs a key damper in the stovepipe to reduce draft.

 

[Deppizzymo]

With that tall of a flue system the stove probably needs a key damper in the stovepipe to reduce draft.

I've read that before on the forums. I mentioned that to my installer and they said absolutely do not do that. I'm not saying I don't trust that recommendation just saying my installer is definitely not going to help me add one lol

 

[begreen]

Ask your installer what Lopi says is the acceptable draft range for the proper operation of the stove and if he has a manometer to come out and test the flue system to see if it is within tolerance.

 

[Deppizzymo]

Ask your installer what Lopi says is the acceptable draft range for the proper operation of the stove and if he has a manometer to come out and test the flue system to see if it is within tolerance.

That's a good idea..I will contact them Monday. I might run smaller loads or let the coals completely die out until then.

 

[begreen]

I see nothing in the manual prohibiting a key damper and a strong suggestion that excess draft needs to be corrected.

From the manual:

Drafting Performance

Draft is the force which moves air from the appliance up through the chimney. The amount of draft in your chimney depends on the length of the chimney, local geography, nearby obstructions and other factors. Too much draft may cause excessive temperatures in the appliance and may damage the heater. Inadequate draft may cause backpuffing into the room and `plugging' of the chimney. Inadequate draft will cause the appliance to leak smoke into the room through appliance and chimney connector joints. An uncontrollable burn or excessive temperature indicates excessive draft.

 

[Sealcove]

I switched to a new liberty a year ago and ran into the same thing. I am running into a similar stack, of 25-30’ + of Excel pipe (I forge the exact length). I did have to add a pair of 45 degree bends to get the spacing I needed so my stack isnot completely straight up. I found that with certain loads of wood I could get very hot fires that exceeded the Liberty’s ability to control. While I did a self install, my dealer (also an installer) also advised against a damper in the chimney. I reached out to Travis and they saw no issue in adding one if I had too strong a draft, and all evidence indicated that I did.

I ended up adding an Excel damper (key damper pre installed in a short section of pipe). When I get the strong draft conditions, which is only on occasion, the damper has been a perfect solution for slowing things down to an more comfortable rate and temps. Loading pattern and wood obviously play a role too, but the damper in the system is nice to have.

 

[Hoytman]

Smaller loads, larger pieces, packed tightly together, or any combination of the three. Key damper is a good safety to have even when doing any of the above combinations.

 

[Todd]

Yeah I think all stoves are tested with a 15’ chimney and controlled draft so the manufactures build these stoves to run optimally at that height. Once your up over 20’ straight up imo you either need a pipe damper or need to modify the combustion air to keep it working like a 15’ chimney.