Flame time

[Flashback87]

I've seen this topic covered a few times in my search but I did not see a lot of answers. I'm hoping to see how long everyone is seeing actual flames in their stoves or inserts.

I've tried multiple techniques but seems the most I can get is 3 hours of actual flames. I'm trying to determine if this is typical or if I should be seeing flames for longer.

What's everyone else seeing?

I have a true north tn20 free standing stove and burning hardwood, north south loaded.

Thanks!