Pellet Stove blowing smoke into room

I took the pictures after the smoke was cleared (and I could breathe again)..

He put the caulking after it was cleaned, he put on two tubes of caulk. Right now, I don't know how to get at it again.

Could a brush pierce the tube - I think they just used a shopvac. How can tell if there is a leak in the flex connection? Is it too late to put on a clamp?

You could add a clamp at anytime. If the used a pellet vewnt brush which is soft nylon, I doubt it would wreck the flex. But it would stress it enough to make the sealent leak.

Only way I know to find the leaks is with a bright light while its just starting(smokiest). If its smoking that bad, I would say you should be able to see whereits coming from. Otherwise don't run it until you have the guy come back to fix all the leaks. Make sure he runs it while he there.

Do you have a working CO detector in the home?

Sure do.

I'll add a clamp and see if that improves things. For some reason it seems to be coming from the right side of the machine, but smoke is tricky to nail down. I'll keep trying anyways.

What is the flex pipe for. Is it hooked to the tee for exhaust or is it fresh air intake?

The flex pipe is hooked to the tee for exhaust.

Should I consider replacing the flexible pipe? This is a fireplace insert by the way, just realized I forgot to mention that in the beginnning.