VC Intrepid Flexburn Woes / Help Diagnosing burn/smoke issues

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Wannabe

New Member
Oct 23, 2026
1
Massachusetts
Hi there,

We've had our VC Intrepid Flexburn for 3 seasons now and it's been really finicky/hard to maneuver. It's a long shot, but if anyone has dealt with similar and/or can see the pattern in the issues, any advice would be amazing!

Our primary issue has been around smoke/smouldering. From most to least concerning:

1. The smoke is much thicker coming out when the damper is closed; even if the cat probe (oem) reads hot enough, the stove is hot (600-800STT), and there's a healthy ember bed. Removing the damper almost immediately produces less smoke. I'm worried about creosote buildup (and/or annoying the neighbors, it's thick and descends into yards). Our wood should be dry enough (seasoned 2yr+), but a moisture meter is in the mail to confirm
- Found this similar thread that pointed to wet wood

2. The air intake control doesn't seem to have much effect when the damper is open. It does something, but the fire will build up to 800 STT if there's fuel even with the least intake. This is frustrating because we are forced to use the damper to prevent overheating, which has the aforementioned issues. Maybe this is by design The air intake does seem to work OK (but not perfect?) when the damper is on.
- Related thread but not explicitly about open damper

3. The stove can sometimes spill smoke when starting up / I have to take care to burn some newspaper close to the liner to establish a "path", and even then I worry if it doesn't immediately catch

4. The glass gets hazy within minutes of firing up and has established black buildup even after a couple hours burn (always in the same places where the air flows radiating out from the edges of the glass)
- Related thread says this is a leak and/or bad design

Now (1) is a puzzler because it seems to be having the opposite effect that I'd expect from a secondary burn. It's possible our cat has died due to age/overheating, but even without it, I'd expect some reduction based on reading the manual. Or am I misunderstanding how secondary burns work?

It feels like so many things could be wrong--maybe it's a drafting issue (3's smoke feels like bad draft), or a leaky gasket cooling the smoke before it exits, or a bad cat. It's worth mentioning it's a stainless steel liner (unknown if insulated) with a T-shaped connection to the back of the unit (the collar faces back instead of up). I wouldn't rule out a bad install either, the installers had no idea what they were doing.

Sorry this became so long; I so desperately want this to work. I grew up with a wood stove and loved it dearly, but this VC has been nothing but trouble.

Thanks for your time and help!
 
You make no mention of the chimney, probably information the experts will want to know. Details like diameter, length, type, last time it was swept, number of bends and the angle of the bends(if any).

How old is the CAT and how many hours of use has it had? Once your moisture meter arrives post your test results.
 
Have you tried the dollar bill test to check your gasket integrity?

Is the liner insulated? When you had the liner swept, what came out?

How was the wood stored while drying? Does the stove act differently if you burn a load of kiln dried 2x4? Some species available to you in Mass are going to take over 2 years to fully let the water out! The meter will be able to rule out a big variable!

And lastly VC stoves have a finicky reputation!