Hi A M, maybe I can help clarify things a bit for you - I've got a Drolet Austral which is essentially the same stove. Long story short you`re running it way to cold. How to know when you`re running it properly is as follows:
It sounds like you have a double walled vent pipe on the Myriad correct? If that is the case then yes you need to drill an appropriate sized hole roughly 18 inches above the stove top for the thermometer you purchase that's designed for double walled venting pipe. (same as how I'm set up.) Then the thermometer just slides into the hole, job done.
Secondly it's an excellent idea to have a thermometer on the top of the stove. For both thermometers I went to my local hardware store that sells woodstove "stuff" and happened to be SBI in particular which is the manufacturer that makes the Drolet stove. (In case you were not aware of that.) They are cheap, and frankly I can't comment on the quality of the thermometers but hey they work well enough.
Now how to operate:
Your temperature reading goals after you've got the stove up to running temp:
-Thermometer on the vent pipe should cruise between 500-700f and in most cases will hang out between 500-600f
-Thermometer on the stove top should read between 600-700f.
From my experience it's actually very important to have the vent pipe thermometer as I find that if I'm not careful I can easily get that waaaaay to hot long before the stove is up to operating temp. On the flip side if you only have that thermometer it's quite possible you won't get the stove up to temp, or at least not as efficiently as you could.
From a cold stove I achieve this by opening the bypass, pull the air intake control wide open, light the fire and leave the door cracked open - by that I mean while the door is wide open turn the door handle so that it's in the same position as when the door is fully closed and then push the door closed until it can't go further - the door closer hits the body of the stove and stops it from closing properly, thereby leaving it cracked open.
Now I monitor the stove, it flames up quickly, keep an eye in particular on the vent pipe thermometer, it will climb pretty quickly, once it's up above 500f I usually shut the bypass. This slows down the vent pipe from heating as quickly. I also start closing the door a bit more, but watching the flames so that the stay "strong" not "lazy". The stove body thermometer should be climbing but of course not as quickly.
Once the vent pipe hits 600f I usually can close the stove door completely. (You can close it much earlier to be honest - the only advantage to keeping the door open a crack is the stove gets up to operating temp a lot quicker I find.)
Now watch the flames - you should soon see the secondaries firing up - you'll know they are going as you get what looks like powerful flames that look almost like a blowtorch blowing straight down from the top of the stove. The more fire you've got going across the top of your wood load the hotter the stove gets, and the quicker it hits that operating temp. Keep an eye on the vent pipe thermometer! If you're not careful it will climb very fast. Personally I've never had mine outside of what the gauge reads as safe operating temp although it's been up a bit over 800f on a few occasions. I never let it stay there - if it does hit that temp close the air controller off completely and wait, usually 5 minutes and you'll see the temp drop. Let it get down to 700f or lower. Once it starts heading back down I crack the air control open again to keep the fire building so the stove body continues to get warmer.
I can't tell you how much to open it because that is totally dependent on your particular setup, how much draft you get etc. With mine I crack it enough that I can see the coals brighten up and the flames perk up a bit.
Anyway, I keep juggling the air control if I have to get the stove warmer till it's up around 600f, at that point the stove will happily cruise along on it's own. At that point you have to figure out where your air control needs to be positioned to hold that temp, but I think you'll find it fairly obvious, you'll have a reasonable amount of flame although nothing crazy - certainly you shouldn't see a big wall of flame when you look into the stove!
At that point you should be able to pretty much leave the stove alone till the next time you need to load it.
What's the smoke look like coming out your chimney? Once the stove has hit it's operating temp it should be virtually invisible. If in the past you've always seen smoke then that's another sign you're most likely not running it hot enough.
A note on wood - get a moisture meter if you don't already have one and test just how dry the wood you got actually is - split one and stick the probes in the middle of the split. If your wood isn't very dry then it's strongly recommended to burn it a bit hotter then cooler particularly earlier on in each load - this will help dry the wood itself out while it's burning, plus hopefully help less creosote from being formed on the chimney.
A note on loading the stove - I find it prefers a full load. By that I mean I fill mine till there's hardly an inch between the wood and the underside of the top of the stove. it likes nice big chunks too! Don't be shy!
But watch it as it will get hotter faster with a full load and it's way more likely to get out of control with a full load. But it will also run a long long time without filling if you do that.
Well, hopefully this will help you out a bit, happy burning!
Oh! Lastly - as mentioned in other posts cleaning your chimney while no fun is a wise idea! If you've been burning a cold fire for a while who knows how much creosote you've built up
The last thing you want is a chimney fire. I strongly recommended especially now if you continue to use the stove to monitor both the vent pipe temp and go outside and make sure there's no flames shooting out your chimney
Especially if you are only now going to be getting your stove up to it's proper temps. If you're not comfortable doing the job yourself then pay a chimney sweep to do it - it's not a huge cost plus you could probably talk them into installing the thermometer into the vent pipe if you're not comfortable doing that yourself? Consider the cost of a chimney sweep as being much cheaper then dealing with a chimney fire. Certainly it's cheap insurance at this point. Plus it will be a valuable learn to see how much he actually cleans out when he does the job.
E.