The technical question, and what settles it
Is the appliance correctly installed for its listing, is the flue intact and correctly sized for it, and are clearances to combustibles respected? Those are findings, not opinions. A Level 2 inspection with a camera scan produces them in writing. On rental stock in this county the recurring findings are a stove installed by a previous owner without regard to its listing, and a flue sized for a heating system that was replaced two conversions ago.
The regulatory question, and who owns it
Rental habitability requirements and municipal fire and building codes are set locally and change. Burlington, South Burlington, Winooski and the smaller towns do not administer them identically. A chimney contractor is not the right source for what your obligations are: your municipality's code or health officer is, and the answer is worth getting in writing. What we can tell you is the condition of the equipment, which is what any of those conversations will turn on.
The insurance question, which is often the strictest
Policies covering rental property with solid-fuel heating commonly attach their own conditions: an inspection at a stated interval, a professional installation, sometimes a specific report format. These conditions are contractual, not statutory, which means they can be stricter than any code, and a claim is when people discover which conditions they had. Reading the policy before the heating season, and booking to its interval instead of to a general rule, is the cheap version of that discovery.
Documentation and the tenant conversation
Two things reduce trouble more than anything else. A dated inspection record for each heating season, kept as a file, not a memory. And a written explanation given to the tenant covering how the appliance is operated, what fuel is appropriate, what to do if it does not draw, and who to call. Most rental solid-fuel incidents involve operation instead of equipment, and the operation half is the half nobody documents.