Sweep that cheminée

Households with open fires or wood-burning stoves must have chimneys swept once or twice a year depending on local rules (see the règlement sanitaire at your local mairie) and once in the usage period.

It is the responsibility of the person living in the property to do so and a professional must be used (check for OPQCB Qualibat certification).
Costs will be €40-€80 and the ramoneur will give a justificatif de ramonage for your insurance.