repair oven - who is responsible?

[Peter Fokas]

Recently purchased an investment property in Newark NJ that had already had tenants living there that are MTM with no documented leases.  We have not sorted them out yet in terms of getting them on signed leases yet but tenant has been complaining that two of the burners are not working in the oven and wants it fixed. The previous owner never fixed it. Who is responible to fix appliances?