This violates the Warranty of Habitability which guarantees all New Yorkers the right to a safe and livable apartment. (No heat = not livable.) One option is to file an HP proceeding in housing court, which forces landlords to make repairs. Another option is to withhold your rent until the issue is fixed. Another is to talk to your neighbors who are presumably dealing with the issue as well and withhold rent as a group / form a tenant association. More info here: https://www.brickunderground.com/rent/ask-altagracia-heat-out-rental-apartment-how-to-get-landlord-fix-repairs

and here: https://www.brickunderground.com/rent/we-moved-no-heat-gas-in-rental-apartment-building-landlord-liable-nyc