Another FPX Large Insert Thread....

So as not to hijack the other thread. Here are the facts as I know them presently.

1. Insert installed today by a certified installer. Insulated liner up a two story exterior chimney, custom insulated block off plate. Old smoke dragon in the basement feeds into the main flue, no independent liner. That dragon is not in use so the only thing going on in the flue is the new liner...it was wrapped in insulwrap, taped at the seems, wrapped in wire mesh.
2. Ran a break in fire...a few splits of kiln dried cut to about an inch. Used newspaper and whatever fire starter nugget they gave me. Seemed to pull well up the flue, some minor spillage, but I ran the small fire with the door cracked per the manufacturers recommendation. Fire lasted 45 min to an hour. Only part of the insert that I couldn't touch was the glass...though admittedly I didn't try, just assumed since it seemed to take on some decent heat. The surround and face were warm, but not really hot. Primary air was open, bypass open as recommended by the installers. Window slightly cracked to help with the fumes.
3. Wife comes home a few hours later. I go to show her the install and mechanisms for control. The bypass wouldn't budge. Stove slightly warm. I figure something is wrong and I'll just call the shop tomorrow.
4. Check it again after dinner and it will slide. I look up in the stove and can see that the plate is sliding open and closed. It's not as smooth as I'd like, but it's functional.
5. Figure it was just some manufacturing gunk cooking off so I decide to do another slightly larger break in fire. Same story as before, only I didn't use the fire starter nugget. Firebox fills with smoke and isn't drawing well up the flue. The bypass is open for sure, I have a window cracked, and the door of the stove cracked. Abnormal amounts of smoke are coming out, so I shut the door. I'm getting ok flames, but certainly not what I'd expect. Plenty of heat in the box to make it draw at this point. Even now, when I crack the door slightly, I get significant spillage to the point my wife has asked that I quit checking. The box just isn't clearing smoke like it should...it's not even manageable for adding new wood if I wanted to.
6. The primary air can control the small fire.
7. Its 22 degrees outside and snowing.

Help me understand what might be going on here. Window has been cracked the entire time. Fire has reached a point where there shouldn't be smoke in the box with the bypass open, yet a few seconds after being open, it's spilling. The bypass is still sliding so I'm guessing it was just some gunk cooking off. I have not shut it all the way...only moved it enough to see that it's sliding.

For reference, here is a picture of the exterior chimney. Insert is on the main floor.

Thanks for the reply. I did see that about the rod and am surprised it hasn't been addressed. But the matter of spillage to me is alarming. I had a window cracked for the fumes so there was no competition for air. Smoke dragon shouldn't be an issue (I think?) since there is now an independent flue for the insert. When it was an open fireplace, I did the same thing you describe....light some newspaper, hold up in the flue and warm it. Now it's an insulated and smaller flue that had a fire burning it for close to an hour. If a newspaper could get a larger/harder to warm flue to draw, it doesn't make sense to me that a small hot fire burning for a while wouldn't hold enough draw to open the door.

Another thing I've just thought of is that we're in the process of converting from oil to geothermal heat pumps. Downstairs isn't operational yet, but the upstairs is running. Doesn't make much sense since it's drawing the air and putting it back, but might be relevant to the conversation.

Previous thread I started that gives some specs of the home.
https://www.hearth.com/talk/threads/considering-another-insert.102610/

Ok....I haven't been clear and the pictures were dated by a week or so. The smoke dragon was disconnected from the flue before this install..Only really brought that up to give relevancy for potential issues. It's illegal in this state now to have two devices using an unpartitioned flue. The entry point in the basement is now sealed with durock board so I could get the install Permit/performed.

I'm stumped. .

So I figured I'd give another try this afternoon. Lit some newspapers in the box and went outside. Smoke is coming out the chimney. Warmed the flue up with several more newspapers. Started kindling fire. Still don't get all the smoking pulling up, so I close the door with primary air open all the way to prevent anymore from getting in the house. This is the third fire, so I slowly built it up with the bypass open until it was a pretty normal fire. When the door is closed, I can see the flames funneling toward the bypass. I open up the window about two inches and then open the door to the box. Less spillage, but still more than I'm used to on my other insert. Decent size fire burning now. Some minor spillage when I added some more wood, but it seemed to be back drafting from me pulling my arm out. I don't think there is anything wrong with the unit/install other than the bypass door that takes a little muscle. Even with just a few splits burning, it can push out some heat. Wish the blower was a bit quieter though.

And the blower just threw out some sparks and quit working. Ugh.

Yeah. I was really surprised at the sound of the blower. Much much louder than my alterra on high. Draft issues seem fine with a coal bed.

First legit fire is down to a two inch coal bed now. Impressive heat production, though a lot of it ends up at the top of the stair well. Not terribly concerned by that since the new heating system has a humidifier that will run the air handler to keep things at desired humidity without running heat pump if temp is right. Should work out nicely with the two inserts pushing dry heat. I'll clearly need to get my wood supply efforts ramped up. should be fine next year, but year after is looking bleak. Spring should yield a few cords on my land alone. Blower situation is unfortunate, but I'm certain that will get remedied since it was on maybe an hour total. Email into the stove shop already.

Went from third break in fire to a legit fire this evening...no smoke spillage once a coal bed was established. Curious as to where the air inlets are on this unit though. The manual isn't much help. I requested an insulated block off plate to stop any unnecessary warming of the masonry yet I feel some draft around the unit. I saw the blockoff plate, though not sure if it was actually sealed off with furnace cement or caulk. I have the unit completely shut down right now and can hear a whistling. Maybe this is part of the drafting issue?

and for the record, no idea what folks complaining about dirty glass are talking about. Even with a lazy draft on the warm up fires, I only got a slight haze. Wiped it off with a paper towel before this last break in fire transitioned to legit fire and that only produced a little bit of fog at the corners. Here is a picture of the coals after burning some legit splits....by no means packed and after charring and bumping down, mostly open just slightly more than the white line on the primary control. Not bad for loading 16 inch logs for something that can clearly hold 24-26. I'd also caution whoever said they were burning theirs wide open all the time to not do that at all or question their wood quality. With legit logs loaded (16-20% mixed species), I was only full primary for 20-30 minutes max before the logs were charred enough to start choking and enjoy secondary burns. Started the third break in fire around 2pmish. This picture was taken about an hour ago.

Today's fire....still difficulty creating the draft with the start up fire. I think you're right about negative pressure/stack effect. The other insert is in a one story portion of the house. This one is in the two story portion. No issues on that side, just this side. Once the coals are nice and hot, there aren't any issues. I have plans to start working on the upper envelope/insulation as soon as my main floor geothermal goes in. The side walls were covered under the Mass Save program and I'll be able to take advantage of that again this year. Can't burn in the stove Sat/Sunday since the repair tech is coming to fix the blower control. I'll look into some diagnostics then. Right now, without blower, this thing is keeping my living room a balmy 78 degrees with partial loads. The wife might be in love.. I think she even regrets complaining about the time I spent processing wood this past year. Of course the huge viewing window doesn't hurt matters. Definitely produces a lot more heat and lasts a lot longer per load than the Alterra. Looking forward to having the forced air heat with humidistat that circulates air without the heat pump on.

Big thanks to Woodstock for producing some nice literature for diagnosing issues. Really wish these guys made something more modern looking so the wife would be interested. All around great company from what I've read here and other forums.
http://www.woodstove.com/pages/pdffiles/Cures For Backpuffing.pdf

Problem(s) identified and remedies are in progress. After reading tons of websites on negative pressure, decided to investigate why I was losing so much air to create said pressure when it didn't exist that bad before with the open fireplace. What I found was the contractors putting the new duct work and air handler in the attic broke a good size corner off the scuttle door. The door was pretty much a large ceiling tile with 6 inches of rigid insulation on the back. Not hard to see how it could happen really. The door is located in my wife's closet, which hasn't been used since the geo install started. Neither of us noticed any draft, but once I opened the door, I could feel a pretty good rush of air going up into the attic. I've temporarily covered the door with 2 layers of contractor bags and duct tape. The second contributing factor is that I had new insulation put in the upstairs knee walls (6 inches of dense pack cellulose). Well, they had to cut some holes big enough to let a small person in the wall to access the space and there are temporary plywood patches covering the holes. Needless to say, not air tight. Can't do much about that right now other than cover with plastic/duct tape since I have the Mass Save inspectors coming to make sure they job is up to par. So, after covering the leaks with plastic and creating a nice heat cap with higher temperature upstairs....no spillage at all on the last reload and a solid draft up the flue. This also increased the temperature considerably downstairs. Almost too hot in the living room.

Went to batticdoor.com at the recommendation of my Mass Save inspector and ordered a triple sealed R-42 scuttle door. My attic is only R-30, but not air tight to the living space. Any thoughts on putting flooring down over the R-30, caulking and taping the seams to make it more more air tight (easier than pulling pulling up batt and loose cellulose to air seal), then rolling fiberglass batts across that? Would create a better air barrier, allow insulating up to R-50, and save me the money of having someone furring the 2x6 rafters to required size and blowing in spray foam.

The joys of buying a fixer upper. Sometimes I love it, sometimes I question what I've gotten myself into. Grateful it appraised for much more than we paid for it, otherwise I might be in the poor house right now.

FYI, emailed my insurance company today to let them know about the changes. Don't care about insert installs.