J. A. Roby Ultimate questions

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I am asking for a friend who has the JA Roby Ultimate. He and I are not familiar with secondary air stoves and how they work. He's had the stove for 3 years and has always had problems with smoke coming out of the door when opened to refuel etc. He doesn't know what the problem is and wonders if it could be the draft control itself.

Could you please explain the workings of the draft on this stove, and if it differs in any respect, generally, from say a Drolet stove.

If smoke coming out of the stove when the door is opened is an inherent problem with the Ultimate that would be good to know too.


Staff member
Nov 18, 2005
South Puget Sound, WA
Most likely this is not the stove. It's a relatively conventional design tube secondary stove. Possible causes are weak draft due to an inadequate or poorly setup flue system or the stove is in a negative pressure zone. If you can have the friend log in here with the particulars of the installation we can walk through possible solutions. They should include a detailed description of the flue system from the stove top to the chimney cap and a description of the location of the stove and house. Basement locations in multi-story homes are frequently a negative pressure zone with this issue.


Minister of Fire
Feb 16, 2014
The Ultimate really pushes the boundary between needing a 6" flue and 8" flue, 3.75cu fire box creates a lot of static air space when the door is open, decreasing the vacuum of the chimney, a larger flue outlet would help this stove, but it was made to push the limits. Also a restrictive flue cap can cause fluctuations with draft.
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