Feedback on newbie observations - Flue vs SST; Air wash ignition, temp increase prior to coaling

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New Member
Dec 30, 2023
West Coast
This year I finally decided to make the shift from a conventional fireplace and installed a Drolet 1800i running a 6-inch flex pipe covered with insulation up my 12ft chimney (right at min height for the insert). I've enjoyed around 40 fires at this point, and the heat output and elimination of the old stinky fireplace odor is fantastic (ie happy wife). I've mainly been burning some cypress wood given to me from the bark beetles, and some mixed in avocado and other random wood types from my pile. Wood all tests below 20% moisture. When starting a fire I use dry branches and burn them down to coals and load it fullish of wood, this is usually 4-6 splits depending on size, 2 high, and have done both EW and NS loading. Love the forum and have been researching for my install and dreaming about the insert for a couple years

Observation 1: My flue temps when cruising with primary air control to the minimum are around 500-650F normally measured directly with a internal thermocouple, 18" above the stove, on a Auber meter. The insert stove top and top front corners usually run around 150F cooler than the flue (350-500F). Measured with IR gun. These temps are with the fan on high, I've never run with the fan off other than when starting the fire. Most posts on temp comparisons are from free standing stoves rather than inserts. It seems my flue temps are in the "normal" range; but higher than what others are reporting (ie 400F). Others also report higher SST values compared to flue, but maybe this is for free standing stoves and the insert with blower lowers the measures SST? Any feedback?

Observation 2: My burn times for visible flames are about 2-3 hours, which seems normal for the cypress which is a soft wood like pine. I easily get another 3-5 hours of heat from the coals, which is fine for the mild Cali temperatures. The flue will cruise at the range mentioned above, but at the end of the burn cycle maybe 30 minutes prior to coaling, the system will increase temps after running steady for 1.5 hours. Usually I get around a 50-100F increase in flue temps. This morning I went from cruising at 600F to 730F, then into coaling. The secondaries are clearly running hard and I will also get flames at the glass (maybe from the air wash) I haven't seen others discuss this heat event, but didn't search now that I think about it. Do others also see this heat excursion? Added a pic from the fire this morning.

Observation 3: The tape the manufacturer puts on the door gasket is ridiculous. It created an air leak at the gasket ends, as described by other in various posts. This air leak caused some dirty class early on for me, and I fixed with high temp red RTV (also suggested here); and using aluminum foil. I've done the dollar bill test and the gasket feels secure everywhere.

Observation 4: In addition to the mention of flames on the door glass in observation 2 (sometimes); I had one fire where I decided to take small branches and build a 4 high log cabin fire during startup (scared to try this again). It lit great, and I closed the door with air control fully open. Next thing I see are the gates of hell in the stove and I went full closed on the air. The gates of hell remained for 30 minutes, and air wash seemed to be pushing flames down the glass. This was before the red RTV gasket fix, so might have been caused by a leaky gasket but it blackened the bottom 1/4 of the glass. The part that bothered me with this fire was that I was getting smoke out the chimney. I only had stove top temps at this point of my life and they werent bad as it was early in the burn (550F) as I remember. I didn't know what to do, so I just paced in and outside watching the smoke outside and gates of hell inside. Wife asked if everything was ok and I played in cool with a "yes" and sat my ass in the lazy boy till it subsided. I found a post from another member that took a picture of the smoke (wish I thought of that at the time). Others said he overwhelmed the stove with fuel. Any thoughts on what to do in this event, seems like not building log cabins with sappy dry branches is the best way to avoid it.

Observation 5: The fan made quite a bit of noise from vibrating in the front of the metal casing. I first just laid a small piece of wood against the shroud and it quieted the vibration. Later I attached some magnets that have just enough weight to avoid the noise from the vibration. Seems like something they should supply with the stove as the noise was awful (wife not happy, and she had to raise her voice to express it).

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I'm a stove newbie, but here's my 2 cents.

Observation 2: My burn times for visible flames are about 2-3 hours... I easily get another 3-5 hours of heat from the coals... the secondaries are clearly running hard and I will also get flames at the glass (maybe from the air wash)...

I get about the same flame & coal times... I'm on the East Coast with a completely different stove, so it must be pretty normal.

Those flames look fine, but very aggressive. There's so much off-gassing that the fire is using all the air it can get to burn the gasses. Like driving 90 on the highway, it's not bad for your car, but it's not very fuel efficient. You can cut down on the off-gassing by turning down your air sooner, or loading less fuel, or loading it tighter (loose wood will burn hotter & faster).

Observation 4: ... I had one fire where I decided to take small branches and build a 4 high log cabin fire during startup... Next thing I see are the gates of hell in the stove... I was getting smoke out the chimney... Any thoughts on what to do in this event?

Fire is the convergence of air, fuel, and heat. That log cabin of small branches has lots of surface area between the air & fuel, so it's going to burn fast. The smoke was probably unburnt fuel, because your stove air is limited. If you open the stove door wide open you'd probably have less smoke (but way more fire). You could have probably knocked down the log cabin with a poker and laid the branches parallel. If they're all on the floor, or bundled tightly together, there's less air/fuel surface area, so there will be less fire.

Enjoy the burning season, sounds like you're off to a great start!
Sounds like you are doing ok. Each fire is a bit different. Thicker splits will burn longer and slower. Turning down the air as quickly as possible without killing the flame will help moderate flue temps. FWIW, we often run about the same flue temps. My guess is that with the blower off the stove temps would be about 50-100º hotter. It's ok to try this so that you know how the stove will behave during a power outage.