Problems with an early model Quadra fire 5700 step top woodstove

Im new here so am unsure where to add a new thread.
Ok so I have a highly modified 5700 woodstove. It was in my shop for many years and got little use. Now, after mods, its in our home as the main heat source. First year- no problems. Second year, somke / fumes sometimes leak into our home. Not a lot, but its obnoxious. The obvious issues have been checked, it doesnt appear the chimney is downdrafting. All door gaskets have been replaced. Heres my question. This stove has the primary draft and secondary draft in the front. Theres some kind of mechanism to transmit motion to open the secondary. I believe that is where my problem is. If anyone has ever owned or worked on this stove, you know its odd. The sheet metal panels that wrap around the stove are attatched at the rear with screws, but also are welded at the front and rear. To gain access to the rear it appears youd have to grind out some welds. Uh………..what?? Heres specifically what some tests have determined. This stove is hard piped to the outside, so no makeup air is pulled from the home. When I place an incense stick outside and burn a hot fire, the circulating fan blows hot air and the odor from the incense. Theres no holes in the makeup air plumbing. If the fan is pulling odors from outside, its no doubt pulling smoke / fumes from the stove too. When burning the stove without running the fan its ok almost all of the time, but when burning at a lower temp I will sometimes smell wood smoke inside. Chimney was cleaned out at beginning of the season. Stove has been shut down twice, disassembled, cleaned, and gaskets rechecked. Has anyone else had a problem like this? Regarding the modifications……….well:
I had a metal fabricator cut up some 5/16 plate. I designed and welded a water jacket to the top of the stove. Welded in bungs for feed and return water lines for radiant floor piping. T and P valve, an aqua stat, and radiator type bleeder valve also installed. The system works beyond my expectations. I have a lot invested in this equipment. If I have to grind stuff apart I will but would appreciate any input. Thanks in advance!

 

Tell us about the chimney.
Have you pull the firebrick out, give the firebox a good inspection for holes/rust?
Oh, and welcome to FHC!

 

Yes, Welcome!

If you're smelling smoke inside then you're most likely having a back drafting or down drafting issue. Try opening a window a little bit and see if that helps clear the issue. You should feel air coming into the room from outside. Not leaving the house. Also a lot of ventilation inside the house that exhausts to the outside can also affect this. ie stove exhaust, bathroom venting/fans attic fans and the like.

Chimney height from the top of the stove to the cap is important. The smoke is most likely coming into the room via the air intakes as you described, but you really should only smell smoke when the loading door/ doors are open and even then only a minor amount. What happens when you open the loading door when the fire is burning? All air open and damper open if you have one. If you get smoke back into the room, then that could also be an indication of negative pressure.