If you landlord installed a new exhaust hood in your rental over the stove and the hood is not working, then your landlord needs to remedy the problem immediately. He/she installed it and it does not work. Most importantly, it could be a health issue due to the smoke.I would write him seeking its repair by a set date. If he does not remediate it by then, your recourse is to consult with a landlord tenant attorney and/or contact your local health department for an inspection of the rental.